10 years after you made this video, you're still spreading knowledge can't thank you enough for the last piece of my electrical puzzle. I appreciate you so very much.
(95 1500 tbi) when all else fails, check the tach wire at the coil for ground.. If it has constant ground, a quick fix to get ya rolling is to clip it. The coil is signaled by ecm through the other white wire found in the second connector on the coil and these 2 splice into pine another inside the coil. The tach wire is finding a ground (i haven't began my search for it so ill try to get back here with an update) and that ground is trying to energize the coil anytime you hit the key and with enough time burns up the coil.. So if clip the wire orfix the ground, but still no spark.. Test your coil that you've likely just replaced or had replaced.. Hope this is helpful to someone nonethless
What's up everybody, I have a 95 Silverado. Kinda had the same problem, I put a towing cam in it this past summer and the computer went nuts trying to figure out what to do. I racked my brain for a week or so till I watched this video. All I had to do was unhook that single wire plug( 95 is under the dash on passenger side) and leave it unhooked set my timing and let the icm do the job. Runs like a champ
Wow! You just pointed out what should have been obvious to me! I forgot all about the timing wire bypassing the computer. This will tell me right away what my problem is
This could also be caused by a bad pickup coil in the distributor. I believe autozone can test the ICM but don’t buy one there. Get it from a higher quality supplier like NAPA.
I have a 92 gmc k1500 350. Only thing I have not replaced was the Ignition Control Module Relay. I ordered it see what that does. Currently it acts like no vacuum advance. It cuts out won’t pull. I had a pulsing idle replaced the knocks sensor that solved that I’m almost at 100 percent now. I’ll put that Ignition Control Module Relay in see if that’s it. I changed the cap and rotor wires and plugs. New coil as well. New ecm new computer. I bought this truck brand new so only the Ignition Control Module Relay hasn’t been replaced. Can anyone give me suggestions please?
Agreed just went through 20 minutes of U-Tube videos Looking 👀 for the Wiring Diagram on A 1990 Chevy TBI EFI and lots of CLICK BATE ) but you have the BEST information ℹ️
My husband has 98 Sierra he has changed everything,hoping this is his problem...will turn over but won't fire...we had no clue about an ecm,until this web search,hes outside ride now hunting down that black tan wire,trying to do what you said for retiming... praying it works..thanks alot for the video
Great idea for me to try. Im having an erratic tachometer and severe engine miss in my 88 4.3. It will only run for a second or two, then die. I had to get towed home last night. Pickup coil and module have been replaced within the past year and so has TPS, IAC, MAP. Im suspecting knock sensor or Spark Control Module. Thanks for reminding me about the little brown wire. 👍
Please help -Ok I have a 88 with the same coil - on the side with the thicker wire -the wire wire comes out of the plug that goes to the cap that plugs into the coil comes out and is cut - it’s Allways been like that - where is it supposed to go 🤷🏾♂️
i have a 92 s10 pick up and this may be my problem, i changed the coil and cleaned up distributor but still randomly starts, I'll try ti unplug the brown wire you pointed out and see if it helps, thanks
It should still crank with the ICM before swapping to the ECM. The brown wire connects the ECM to the distributor. The only time you should have to disconnect the brown wire is to do the initial timing.
Good advice,.... i have a 93Sierra that never stalls but often will not start do to no spark...then one day when it feels like it she'll start ! Should of never gone away from good ole points !
Haha, well I do agree that the ICM is a finicky module and it does not like heat at all. Don't buy a cheap one either or it will not last long. I doubt OEM modules even exist nowadays though :(
Thanks for this I just had to put new coil connectors on where someone had cut them off my 87 v20 and had a old school coil on it so I put it back factory.
I had the same issue several years ago. It was the pickup coil but I just replaced the entire distributor. It was easier and cheaper than just the coil.
i believe if you crank it and have fuel pressure out the injectors the pickup coil in the distributor is good.....went thru this on my 92 astro....thought i had bad coil but it was the ignition control module that was junk...the module sends a signal back to the coil to spark so dont assume its bad coil right away..
So i have replaced the ignition control module, ignition coil, distributor cap, rotor and wires, and plugs. I am getting fuel, but still having trouble with it not turning over. When i get it to turn over, it idles but then I turn it off and try to start it again and it won't start. Should I try removing that connector still? What is weird is whenever it does turn over it the radiator fan kicks on right away, but I think that is just a stuck thermostat so going to replace that as well
This could be my issue... mine is a 90 Chevy 350. Replaced three coil module 3 times, last one with ACDELCO. Still isn’t starting. I’m gonna look for this computer wire tomorrow. Pull it... crank it... and see what happens.
Get a Actron CP9690 code tester. It checks live, record, graphing, emissions readiness test, oxygen sensor tests, ABS, SRS, and MORE! It retains the memory of results. There's another without the OBDI cables and it has the same tester. It comes in a black pouch. It has a cigarette lighter adaptor. Out-of-the- box it tests from 1984-2013. It is updatable with a USB cable from EBAY. It comes with OBDI cables for Ford, G.M, Chrysler, and Toyota, and a OBDII adaptor. There are penlight batteries under the cover at the small screw. It is well- lit! EBAY has it.
I'm hoping you can answer this. My truck has a rough idle like it's not advancing the timing. I have done cap, rotor, coil, ignition control module and even the distributor at this point. When we unhooked the wire to set the base timing the truck dies. It show's a code 42 which comes up as ignition bypass circuit error.
I gotta question I have 92 chevy k1500 after tightening thepower wire to the ALTERNATOR my fuel pump wires burnt I replace the wires where the burned a little that issue resolved but while doin so I hooked them straight to the battery to test the pump it still work UT after wiri g it back correctly I have no cli king no spark absolutely nothing when I turn to the key to try and crank the the truck
I'm having a starting issue, I have a 94 1500, I replaced the motor with 1 out of a 89 model, new plugs and wires are on it!! If I were to do this would this be the culprit?! I did not replace the computer or anything! Its spinning over but wont turn over for me. Any ideas would be appreciated!!
Hey when I set the timing on my 91 Silverado at 0 degrees top dead center and then pull the Ecm fuse and put it back in and plug the ecm wire back in and start the engine, I can't see a timing mark anymore, it's like it's so far Advanced that don't want to idle at stop sign, and I set the timing when it was warm so it wouldn't do that ,but it keeps doing that what am I doing wrong? It ran great but the intake gasket was blown then I changed it and then the timing has never been exactly right since.. it runs strong but won't idle so I was wanting to start at 0° but computer keeps changing it too much..
Just looked at your video I got a 1994 chev 1500 Cheyenne I haveing trouble some times it will start and run when not in gear then I put it reverse and it will cut off and don't want to start no more I would have to put gas in the carberrader to start .. can you help me with this problem..
Where is the Electronic Spark control module located on 1993 Gmc Sierra 4.3 6 cylinder? The book we bought says near the throttle body or behind the distributor mounted to the fire wall. We can't seem to find it
I've got a 89 k1500 with no spark. I've put an inline tester on 2 different plugs and it flashes once when I turn the key on and nothing while cranking. I tried the bypass you showed and still no spark.
thanks this is helpful i still aint got no spark after doing all the same mess its a 1996 454 in a Winnebago i wonder how to set the timing or if i need to also can i set it without running by just cranking?
My 1991 will run with with my foot on the pedal and shut off once I remove my foot..any ideas..I've changed fuel pump, fuel filter, distributor and plugs
If the EGR valve is carboned up / stuck open ,broken diaphragm and allowing exhaust gases to pass at low rpm it will not idle very well. Idle air control sensor be throttle position sensor. Your throttle body butterfly flapper could be closing.There must be a slight gap to draw in air at idle.
I have a 91 S10 with a new 4.3 remanufactured motor getting excessive amount of fuel flooding out the truck loading up the crank case with gas what could be causing that
1990 Silverado, 5.7 all lights on dash work when turning key to on, try to start and nothing, starter wont rotate but still powers everything. tried two brand new starters, same problem. one day it starts, sometimes it doesnt at all. Any suggestions?
Farm boy I need some help I just bought a 89 Chevy Silverado 350 four-wheel drive and I have no idea what to do I'm having the same issue to start no crank no spark and my battery terminals getting hot when I try to turn it over help please..
hey I have a 1990 chevy silverado my truck keeps draining my battery and I couldn't find a bad ground im pretty sure the alternator is good and I am on my 3rd battery could you maybe help me out
Best way to find a battery draw is to use a ammeter with a cable clamp. Place the clamp over the positive battery cable and start pulling fuses to see which circuit has the draw. Once you find the circuit, you'll have a better idea where to look to find the issue.
Quick question. I have a 94 Silverado c2500 with a 5.7L. If I use starting fluid it starts and runs fine. No starting fluid it just cranks till the cows come home. This started after using engine degreaser and power washing it off. It started fine after the spray and I let it run for a bit to dry everything up. Was looking fir an oil leak. Any help would be greatly appreciated.
@@farmboy30117 Ok, so replaced the fuel pump relay, same issue, reset the computer and it was flashing code 21, read about it... cut a hole in the bed and replaced the fuel pump... not the problem... Its a long bed so was not able to lift it myself and I filled the tank like a day before this started... Today went and got a fuel filter and a new TPS... Replaced both of them and now it works fine, my code 21 is no longer there so guessing it was the TPS that caused the issue. I can honestly say after reseting the computer the idle is perfect now and it even seems to run better! Thanks for your help man very very much appreciated!
So if I get the no spark situation again, can I unplug the beige wire and see if it starts then ? Can we leave the wire unplugged permanently? I remember unplugging it inside the cab to set timing
Unplugging the wire bypasses the ECM control of your spark timing. If you have spark with the wire unplugged and then lose it when the wire is plugged back in, that would indicate a bad ECM. I wouldn't advise running with it unplugged because you will not have any advance on the timing and it will run poorly at anything above idle.
@@farmboy30117 ok thanks, haven't driven it much lately. Too damn cold here in St.Louis to risk a breakdown out on the road. Did they eliminate this ignition system in 96' ?.
@@timkapeller6948 I'm not sure. I know they went to the vortec engine in '96 which did away with the Throttle Body Injection system. I haven't had any experience with them.
What if it stalled randomly distributor bolt loosend up and no spark after put a new distributor in now I have spark and fuel but still won't start trys to
I have a question 97 350 try and find out where the white wire goes to come off of the have a red wine or white wine and another red wine I'm trying to figure out where this white wall coming up the call
I have a 94 1500 5.7 swapped engine w a 92 suburban 5.7 have spark and fuel but only pops? I changed pick-up coil do I have to unplug the pcm to get it to work?
I was wondering. I have an 89. R3500 with 5.7 I have spark but no injector pulse. I’m guessing bad computer what would you guess. I replaced distributor and fuel pump.
I have a 94 Chevy suburban k1500 350tbi and the ecm fuse keeps blowing randomly and can’t figure out why it only does it randomly wondering if you have any insight on how to trouble shoot it
I have a 1991 k1500 5.7 did a complete tune up except coil, ran great for 100 miles, now experiencing a flat out no power situation, runs rough idle and can not pull a hill or gain speed at all except over time. I can put my foot into it and sometimes it will act normal until I take my foot out of it but than it acts like not running in all cylinders. Oh yes revolution the throttle body as well thanks Don
I have a 1993 GMC 350 TBI that has fire to the coil and to where the coil wire plug’s in to the distributor cap but it is not going through the plug wires what could be the problem with it I have put everything new in the distributor and coil area
Could that why effect it on start up? I had to change my oil pressure sending unit and when I put my distributer back in timing was right but on start up it wants to die right away but if you give it alil gas and let it idle at about 2000rpm for about 30seconds then it's okay.
When you timed the distributor, did you unplug the wire so that the computer wouldn't effect the timing? Not sure, but it sounds more like a problem with the Idle Air controller.
@@randy1ization these trucks do have a knock sensor on the block down low by the starter motor if I remember correctly and I believe you are correct in that the esc module uses the signal from the knock sensor. Esc module was eliminated in a later year in favor of a different way of processing knock signal. Think it was when they changed from ecm to pcm. Have had 2 with esc module and no problems. Have had problem with knock sensor though. GMT400 forum has lots of info on this.
i have an unrelated question. i have same setup, recently had to replace ignition module under distributor cap. its run fine for a while, until starting up a hill the other day and all of a sudden got a loud rattling clanking noise from engine, and loss of oil pressure down to half (20) instead of 40. any ideas? the top side looks good all rockers move good, bottom side looks okay as far as i can tell, didnt get anything out of oil pan. whats your suggestion
Doesn't sound good. Loss of oil pressure sounds like a clearance issue. Maybe spun bearing? I'd definitely want to pull a couple of bearing caps off and look. Good luck.
Is there supposed to be battery voltage from the coil to the icm? My 1991 chevy 5.7 decided to not start last night. No spark. Replaced the icm hoping that would solve it. Now I'm stuck.
@@Michael-wk4yo Kind of funny this came up. Last few week, my pickup was running like crap. Getting crappy fuel mileage. Apparently I didn't put loctite on the distributor bolt when replaced the distributor. It backed out and slowly spun my distributor. If your pickup coil is bad and you replace your distributor, make sure you use loctite on that bolt! Good luck!
Heat kills them more than anything. First though, always buy from a quality auto parts store like NAPA. Don't buy them from Autozone, I've seen multiple failures with those. Next, always use heat sink paste and make sure the heat sink is clean when installing.
i have a 1990 chevy blazer 5.7 k5 i been having a miss in thengine n a hesitation when I press the throttle ive replaced cap,rotor,wires,plugs,coil,n ignition mogel n i replaced the whole distributer n still has the hesitate n miss been hoin on for a few weeks but now when I drive it for over a half hour or more it starts to bog out n backfire then shut off but starts back up and running it will do this a few times then i gota let it sit for bout 20min then sometimes it will start back up......help
+Edwin Padilla You didn't mention a check engine light, so all the sensors are probably ok. Looks like you've ruled out the ignition system, so one thing to check is a clogged exhaust (usually the catalytic converter), too much back pressure can cause strange things. If that isn't the issue, I'd look at the fuel system and make sure your fuel pressure is adequate. Hope this helps and good luck.
I have a 1990 k2500. It starts and runs fine but if you've been driving it for a while (maybe over 15 to 25 minutes) and then turn it off it then won't start again for a while. If you only drove it for a few minutes then it's fine. Then you can shut it off and turn it back on as many times as you want. But if you had ran it for a while and turned it off it won't start until you've waited 15 or 20 minutes. I can't figure out why. Anyone have any suggestions?
You can narrow it down to fuel or ignition by checking the spark next time it won't start. Could be vapor lock or an ignition part getting too hot. Since (I assume) it'll run fine as long as you don't shut it off, it probably isn't the fuel pump.
@@farmboy30117I'm pretty sure it's an electrical issue. Possibly in the ignition. When it doesn't want to start it doesn't crank at all. You turn the key and the gauges go up and down like normal but that's it. So it's not a spark issue. It acts as if you're not holding in the clutch. That's why I bypass the clutch safety switch but it's still doing it. And thank you for your reply.
@@thejohn6614 My first thought is that the starter (or solenoid) is getting hot and not working if it won't crank at all. Is the exhaust factory manifolds? It'd be a pain, but I'd try to take a test light the next time it won't crank and see if you're getting power at the starter or starter solenoid.
@@farmboy30117 it was just not starting and I checked the stater and it was getting power but then it started immediately after. I'll check again next time it does it.
I have a 1991 chevrolet k1500. I changed my throttle body gasket and started the truck up and noticed a minor leak so I shut the truck off. After I tightened the hose I went to go start the truck again and had no fire. I changed the cap and rotor and cleaned the module but still have no fire. Having trouble find the brown wire but I was wondering if you may have an other idea to why I would not be getting fire?
I have a 1989 k1500 5speed and when I unplug wire and run icm it idles amazing but when the pcm tried to idle the truck it just dies and looped and I replaced ecm and prom, and egr, iac, map, tps please help
Might be a little late but it sounds like you’ve replaced all the usual suspects. Since the icm only cares about initial timing I would say your distributor is good. I would double check that initial timing is correct because from what I’ve seen the pcm really picks up the advance on timing.
I have a 89 Silverado old truck just passed inspection the next day I tried to start it and it started to crank then nothing. I've changed battery cables but I'm not a mechanical person so idk what to look for??
Duane, to be honest, there's a lot of things that can cause one not to crank. I'd recommend finding a local shop that you can trust to diagnose it. Some things are: low battery, bad starter, bad starter solenoid, bad ignition switch, broken wire, etc.
Good info. Thank you. I replaced the complete distributor,coil,cap,rotor,plug,and plug wires. Set timing and started up. Set base timing. Shut off truck and will not start back. Any ideas ?
Yea I change fuel pump ,injecters,ignition module , thinking it was that . nothing so then we went and check the grond on the injecters and no spry so that's the issue . I tested it by touching on any ground and spayed.. but how can I fix this problem... i really appreciated your help ...
solid angel did u find out whats wrong ? i have same issue. lots of new parts pump. injectors. distr. n ign. all of a sudden i crank and no spray whats going on?
I have 94 GMC tbi 4.3 v6 vortec, was driving it, shut down like u turn key off no back fire, pop, no noise, I've checked it no spark, will crank but want start, what's my troubles, also have just replaced cap button an wires (+spark plugs) took ingintion modugel off had it checked an was good
I have a 89 suburban, the service light comes on it runs great, the light goes off it runs like crap. Spark knocks, pops and cracks, and u can smell its flooding out. Whats ur thoughts
@@farmboy30117 code 42, I changed out icm under the distributor and the light stayed on for about 2 weeks and ran great it it started shutting off again
Hey regarding that wire that isolates ignition from ECM...I have a 1991 Chevy 1500 and there's a plug there but it's white with black stripe. I unplugged it and tried to start but still no start. My issue is either ECM, ignition module, or pickup coil. I wish I could post a pic of mine. It's in the same area you pointed to but is a different color.
I m having a problem it seems like I don't have power from clips to the injectors for my gmc 1995 1500 z71. I changed my coil,module in distributor and and injector rebuild kit and no gas coming out injector. I hear gas pump cleaned fuel filter and thinking maybe change relay switch fuses are all good I'm stuck
So you probably have a fuel or ECM or Injector issue. (1) Without a fuel pressure tester, it is difficult to determine whether the fuel pump is producing adequate pressure. (2) The pink wires going to the injectors are coming from ECM1 Fuse (20 Amp) and should be hot in run or start on ignition key. Make sure you have power here with a test light or multi-meter. (3) The dark blue & dark green wires come from the ECM which provides a ground path (or ground side switched) to operate the injector solenoid. With no ground supplied from the ECM, there will probably be residual power on those wires. If you supply a ground to the blue or green wire, the injector would spray (assuming it has power from the fused wire and fuel pressure). It is difficult to see if the ECM is trying to operate the injector without a noid light or a special test light because it pulses so rapidly. (4) Check power and grounds at the ECM. You can do a Google Image search for "1995 Chevrolet Silverado wiring diagram" (AutoZone has a good one) that will show where to look for power and grounds to the ECM.
I have a 90 chevy 1500 carberator parts were stolen with truck recovered vechile and finally back together all parts have been replaced any ideas I have a truck now no crank no start no click don't hear fuel pump kick on as well seems like something not powered could starter and solenoid not connected right cause problems
Hello, I'm attempting a MSD Streetfire HEI distributor, I ran a pigtail for the coil, but how do I connect the 4wire harness for TBI pulse? Stock distributor is 2plug, and this new distributor only requires 2pin in?
farmboy30117 The stock is an 8 pin controller, electronic controlled, and the new streetfire is a 4 pin, vacuum advanced. I just need a signal to pulse the injectors. Will the "B" bypass pin provide timing pulse to injectors?
10 years after you made this video, you're still spreading knowledge can't thank you enough for the last piece of my electrical puzzle. I appreciate you so very much.
Mannnnn you're a lifesaver. 800 in towing, 3 sets of plug wires later i appreciate this.
Try gettng aaa roadside. 5 free tows every year
This worked! Purchased a truck with “no spark” 30 second fix!! Thank you!
(95 1500 tbi) when all else fails, check the tach wire at the coil for ground.. If it has constant ground, a quick fix to get ya rolling is to clip it. The coil is signaled by ecm through the other white wire found in the second connector on the coil and these 2 splice into pine another inside the coil. The tach wire is finding a ground (i haven't began my search for it so ill try to get back here with an update) and that ground is trying to energize the coil anytime you hit the key and with enough time burns up the coil.. So if clip the wire orfix the ground, but still no spark.. Test your coil that you've likely just replaced or had replaced.. Hope this is helpful to someone nonethless
hi i had replaced the clips that go to the distributor.my truck would start with starter fluid but now it doesn’t can it be the coil?
@@559Obsalexsame here with my caprice. How did you resolve it?
So my issue is the tachometer wire, how did you fix the issue permanently. I would love have operating tachometer as well lol
What's up everybody, I have a 95 Silverado. Kinda had the same problem, I put a towing cam in it this past summer and the computer went nuts trying to figure out what to do. I racked my brain for a week or so till I watched this video. All I had to do was unhook that single wire plug( 95 is under the dash on passenger side) and leave it unhooked set my timing and let the icm do the job. Runs like a champ
Awesome! Glad it helped :)
How did you set the timing
So u unhooked the ICM witch is the PCM correct.... And u left it unplugged
Wow! You just pointed out what should have been obvious to me! I forgot all about the timing wire bypassing the computer. This will tell me right away what my problem is
Thanks man. My buddy’s 93 k1500 4.3 crank, no start was due to the ignition control module.
Yeah, that's pretty common. Glad it helped!
@@farmboy30117 every morning i have no spark and have to replace my pickup coil. Any idea on what to test
Thank you brother. Can't wait for it to get daylight so I can check this. Replaced my head gaskets and hasn't started since. No spark.
This could also be caused by a bad pickup coil in the distributor. I believe autozone can test the ICM but don’t buy one there. Get it from a higher quality supplier like NAPA.
I am so grateful that you made this video. God bless you and your Family
Thanks Charles! I'm glad it helped!
@@farmboy30117 I could use help on same issue same engine.
I have a 92 gmc k1500 350. Only thing I have not replaced was the Ignition Control Module Relay. I ordered it see what that does. Currently it acts like no vacuum advance. It cuts out won’t pull. I had a pulsing idle replaced the knocks sensor that solved that I’m almost at 100 percent now. I’ll put that Ignition Control Module Relay in see if that’s it. I changed the cap and rotor wires and plugs. New coil as well. New ecm new computer. I bought this truck brand new so only the Ignition Control Module Relay hasn’t been replaced. Can anyone give me suggestions please?
Agreed just went through 20 minutes of U-Tube videos Looking 👀 for the Wiring Diagram on A 1990 Chevy TBI EFI and lots of CLICK BATE ) but you have the BEST information ℹ️
Thank You so much sir. I appreciate learning auto mechanics from people who can explain in a common sense manner. Have A Great Day! 🛻🚤🏖️
Thanks, you too!
Thank you a million times over for taking the time to make this video, I truly appreciate it, you have helped me out. Great video.
Thanks, I'm glad it helped!
farmboy30117 what if the car runs ok but i keept that black / tan wire unpluged what will happe ? thanks man hope u replay to me
farmboy30117 what if no spark still after distributor changed .igintion module. The pink wire is getting no power whatsoever
My husband has 98 Sierra he has changed everything,hoping this is his problem...will turn over but won't fire...we had no clue about an ecm,until this web search,hes outside ride now hunting down that black tan wire,trying to do what you said for retiming... praying it works..thanks alot for the video
@@mikeanderson1994lol lll
Finally someone showing stuff on a 454!
And yes this ain't a 454 but it's the same, and helped me figure out the issue on my 454
Great idea for me to try. Im having an erratic tachometer and severe engine miss in my 88 4.3.
It will only run for a second or two, then die.
I had to get towed home last night. Pickup coil and module have been replaced within the past year and so has TPS, IAC, MAP.
Im suspecting knock sensor or Spark Control Module.
Thanks for reminding me about the little brown wire. 👍
Very good information- you made it easy to understand- thank you -God Bless
I need help 92 Chevrolet c1500 with 4.3 tbi ive got fire at the coil but no spark at the plug wires
Bad rotor dirty distributor cap
Please help -Ok I have a 88 with the same coil - on the side with the thicker wire -the wire wire comes out of the plug that goes to the cap that plugs into the coil comes out and is cut - it’s Allways been like that - where is it supposed to go 🤷🏾♂️
I believe the white wire would go to a tachometer
i have a 92 s10 pick up and this may be my problem, i changed the coil and cleaned up distributor but still randomly starts, I'll try ti unplug the brown wire you pointed out and see if it helps, thanks
It should still crank with the ICM before swapping to the ECM. The brown wire connects the ECM to the distributor. The only time you should have to disconnect the brown wire is to do the initial timing.
@@farmboy30117 ok, well i think its my distributor and rotor, what a ding dong i didn't check for spark first and just did and there's nothing. thanks
Good advice,.... i have a 93Sierra that never stalls but often will not start do to no spark...then one day when it feels like it she'll start ! Should of never gone away from good ole points !
Haha, well I do agree that the ICM is a finicky module and it does not like heat at all. Don't buy a cheap one either or it will not last long. I doubt OEM modules even exist nowadays though :(
Very good job help me out a lot
This video is pure gold thank you!
Thanks for this I just had to put new coil connectors on where someone had cut them off my 87 v20 and had a old school coil on it so I put it back factory.
I'm getting fuel but no spark what do you think is?? Truck was running great than it wouldn't start out of no where
I had the same issue several years ago. It was the pickup coil but I just replaced the entire distributor. It was easier and cheaper than just the coil.
i believe if you crank it and have fuel pressure out the injectors the pickup coil in the distributor is good.....went thru this on my 92 astro....thought i had bad coil but it was the ignition control module that was junk...the module sends a signal back to the coil to spark so dont assume its bad coil right away..
I have a 92 that has done this twice and it was the electronic ignition module under the dist cap.
So i have replaced the ignition control module, ignition coil, distributor cap, rotor and wires, and plugs. I am getting fuel, but still having trouble with it not turning over. When i get it to turn over, it idles but then I turn it off and try to start it again and it won't start. Should I try removing that connector still? What is weird is whenever it does turn over it the radiator fan kicks on right away, but I think that is just a stuck thermostat so going to replace that as well
This could be my issue... mine is a 90 Chevy 350. Replaced three coil module 3 times, last one with ACDELCO. Still isn’t starting. I’m gonna look for this computer wire tomorrow. Pull it... crank it... and see what happens.
Good luck!
Your video was very helpful, well displayed. Thank you.
I'm glad it helped!
the module is to the left of distributer? with one electrical plug?
The ICM (Ignition Control Module) is under the distributor cap inside the distributor.
@@farmboy30117 thank you sir. what is that thing called that is to the left in your video it has a green plug on it and a vacuum line
MAP sensor?
Get a Actron CP9690 code tester. It checks live, record, graphing, emissions readiness test, oxygen sensor tests, ABS, SRS, and MORE! It retains the memory of results. There's another without the OBDI cables and it has the same tester. It comes in a black pouch. It has a cigarette lighter adaptor. Out-of-the- box it tests from 1984-2013. It is updatable with a USB cable from EBAY. It comes with OBDI cables for Ford, G.M, Chrysler, and Toyota, and a OBDII adaptor. There are penlight batteries under the cover at the small screw. It is well- lit! EBAY has it.
I’m getting spark. It no fuel however with starting fluid it does not crank over so I’m not sure why it won’t start
Fuel pump bad, fuel pump relay bad, fuel filter clogged, computer bad...
I'm hoping you can answer this. My truck has a rough idle like it's not advancing the timing. I have done cap, rotor, coil, ignition control module and even the distributor at this point. When we unhooked the wire to set the base timing the truck dies. It show's a code 42 which comes up as ignition bypass circuit error.
What was setting the code 42?
Did you ever figure it out
My gas gauge pegs out when it starts registering gas it will crank and run then any ideas
I gotta question I have 92 chevy k1500 after tightening thepower wire to the ALTERNATOR my fuel pump wires burnt I replace the wires where the burned a little that issue resolved but while doin so I hooked them straight to the battery to test the pump it still work UT after wiri g it back correctly I have no cli king no spark absolutely nothing when I turn to the key to try and crank the the truck
Whats the red inline fuse thats has an orange wire on other end on the distribution fuse block
The coil failure will keep fuel from pumping also so no spark-no fuel will occur.
Mine has spark but no pump on fuwl
What wiring plugs into the block behind the drivers side tire? Someone cut mine
I'm having a starting issue, I have a 94 1500, I replaced the motor with 1 out of a 89 model, new plugs and wires are on it!! If I were to do this would this be the culprit?! I did not replace the computer or anything! Its spinning over but wont turn over for me. Any ideas would be appreciated!!
Will it fire on starting fluid?
Hey when I set the timing on my 91 Silverado at 0 degrees top dead center and then pull the Ecm fuse and put it back in and plug the ecm wire back in and start the engine, I can't see a timing mark anymore, it's like it's so far Advanced that don't want to idle at stop sign, and I set the timing when it was warm so it wouldn't do that ,but it keeps doing that what am I doing wrong? It ran great but the intake gasket was blown then I changed it and then the timing has never been exactly right since.. it runs strong but won't idle so I was wanting to start at 0° but computer keeps changing it too much..
There should be a sticker under the hood that says what the initial timing should be. I'm thinking it is about 8 deg BTDC but could be wrong.
Just looked at your video I got a 1994 chev 1500 Cheyenne I haveing trouble some times it will start and run when not in gear then I put it reverse and it will cut off and don't want to start no more I would have to put gas in the carberrader to start .. can you help me with this problem..
Where is the Electronic Spark control module located on 1993 Gmc Sierra 4.3 6 cylinder? The book we bought says near the throttle body or behind the distributor mounted to the fire wall. We can't seem to find it
It's inside the area the distributor cap covers... It has two screws holding it in and it has two connectors with wires hooked up to it...
Nope
I have a cap on my distributor. The screw keeps sinning and wont come loose any suggestions
I've got a 89 k1500 with no spark. I've put an inline tester on 2 different plugs and it flashes once when I turn the key on and nothing while cranking.
I tried the bypass you showed and still no spark.
have a code 43,23, and 28 im stuck at a dead end any help appreciated
Sir can you tell me if there is a difference in a 94 and a 95 engine tbi 4.3 foe a s10 chevy pick up
I know they went to a vortec 4.3L which had a balancing shaft in it. Not sure if it was '94 or '95 though, but I'm thinking it was '94.
Can the ignition module be placed away from the distributor? Can I mount it against the firewall with a heat-sink?
thanks this is helpful i still aint got no spark after doing all the same mess its a 1996 454 in a Winnebago i wonder how to set the timing or if i need to also can i set it without running by just cranking?
Still not getting spark on mine was running before i put new coil distributor and unplugged wire getting fuel no spark
Check for power and grounds. Could be broken wire or defective parts.
My 1991 will run with with my foot on the pedal and shut off once I remove my foot..any ideas..I've changed fuel pump, fuel filter, distributor and plugs
If the EGR valve is carboned up / stuck open ,broken diaphragm and allowing exhaust gases to pass at low rpm it will not idle very well. Idle air control sensor
be throttle position sensor.
Your throttle body butterfly flapper could be closing.There must be a slight gap to draw in air at idle.
I have a 91 S10 with a new 4.3 remanufactured motor getting excessive amount of fuel flooding out the truck loading up the crank case with gas what could be causing that
Probably a little late, but I think you should check the fuel pressure regulator. It's built in to the throttle body
Thanks I needed to know that as I'm working on a 90 Silverado with a no spark issue😮
How do you replace a 93 Chevy 3500 with a 5.7 v8 manual control box wiring hardness
Mines a 1990 suburban 2500 and i think its the same thing mine just dosnt crank at all
Did you figure it out?
@@jonhsmith2706 yea i did
@@danl878What was it if you dont mind me asking I have the same issue on my tbi caprice
1990 Silverado, 5.7 all lights on dash work when turning key to on, try to start and nothing, starter wont rotate but still powers everything. tried two brand new starters, same problem. one day it starts, sometimes it doesnt at all. Any suggestions?
i have a 82 gmc and i get lights on dash when i turn the key on but i get nothing at all ytrying to start it
NCS on transmission or look under mate on driver's side you will see black tar tap under it is a fuse
Farm boy I need some help I just bought a 89 Chevy Silverado 350 four-wheel drive and I have no idea what to do I'm having the same issue to start no crank no spark and my battery terminals getting hot when I try to turn it over help please..
What does it sound like when it's turning over? Hot wires means high resistance, so either bad terminals, grounds, etc. You live in salt belt?
@@farmboy30117 it sounds like it wants to turn over..but it wont..
hey I have a 1990 chevy silverado my truck keeps draining my battery and I couldn't find a bad ground im pretty sure the alternator is good and I am on my 3rd battery could you maybe help me out
Best way to find a battery draw is to use a ammeter with a cable clamp. Place the clamp over the positive battery cable and start pulling fuses to see which circuit has the draw. Once you find the circuit, you'll have a better idea where to look to find the issue.
Quick question. I have a 94 Silverado c2500 with a 5.7L. If I use starting fluid it starts and runs fine. No starting fluid it just cranks till the cows come home. This started after using engine degreaser and power washing it off. It started fine after the spray and I let it run for a bit to dry everything up. Was looking fir an oil leak. Any help would be greatly appreciated.
Sounds like a fuel issue but very weird for a gas engine to act like this. No idea on this one.
@@farmboy30117 I noticed off or the key on no fuel comes out of the injectors. So guess I can start tracing and testing there
@@hangoversamuiadmin3163 Maybe start with the fuel pump relay
@@farmboy30117 Will do, thanks for the help
@@farmboy30117 Ok, so replaced the fuel pump relay, same issue, reset the computer and it was flashing code 21, read about it... cut a hole in the bed and replaced the fuel pump... not the problem... Its a long bed so was not able to lift it myself and I filled the tank like a day before this started... Today went and got a fuel filter and a new TPS... Replaced both of them and now it works fine, my code 21 is no longer there so guessing it was the TPS that caused the issue. I can honestly say after reseting the computer the idle is perfect now and it even seems to run better! Thanks for your help man very very much appreciated!
So if I get the no spark situation again, can I unplug the beige wire and see if it starts then ? Can we leave the wire unplugged permanently? I remember unplugging it inside the cab to set timing
Unplugging the wire bypasses the ECM control of your spark timing. If you have spark with the wire unplugged and then lose it when the wire is plugged back in, that would indicate a bad ECM. I wouldn't advise running with it unplugged because you will not have any advance on the timing and it will run poorly at anything above idle.
@@farmboy30117 ok thanks, haven't driven it much lately. Too damn cold here in St.Louis to risk a breakdown out on the road. Did they eliminate this ignition system in 96' ?.
@@timkapeller6948 I'm not sure. I know they went to the vortec engine in '96 which did away with the Throttle Body Injection system. I haven't had any experience with them.
When I prime mine it starts but no no injection pulse
That usually indicates an issue with the wiring or bad PCM. Hope it's just a wire issue.
What if it stalled randomly distributor bolt loosend up and no spark after put a new distributor in now I have spark and fuel but still won't start trys to
Mine starts up and shakes a lot know what could be the problem?
Sounds like some plugs aren’t firing properly. Have you give it a tune-up lately?
@@farmboy30117 yeah changed wires and spark plugs and oil change
Hi am Ernest. My c3500 just happened to shut down. No fuel from the throttle body no start. But starts when I prime it. Fuel pumps works. Can u help?
It's probably a little late on the reply, but how do you know the fuel pump works? Did you pressure test it? Does it stay running after you prime it?
I have a question 97 350 try and find out where the white wire goes to come off of the have a red wine or white wine and another red wine I'm trying to figure out where this white wall coming up the call
Hey I have a 90 Silverado I want to add a kill switch can you tell me where the wire is to splice into.thanks
The ones I've seen are spliced into the neutral interlock or clutch interlock switches.
I have a 94 1500 5.7 swapped engine w a 92 suburban 5.7 have spark and fuel but only pops? I changed pick-up coil do I have to unplug the pcm to get it to work?
Sounds like the timing is off. Unplug the wire from the PCM to the coil and set the initial timing with a timing light
Thanks I'll give it a try
I was wondering. I have an 89. R3500 with 5.7 I have spark but no injector pulse. I’m guessing bad computer what would you guess. I replaced distributor and fuel pump.
That would be my guess but I’d check power and grounds to the computer before condemning it.
I have a 94 Chevy suburban k1500 350tbi and the ecm fuse keeps blowing randomly and can’t figure out why it only does it randomly wondering if you have any insight on how to trouble shoot it
Sounds like a wire with a bad spot that grounds out every now and then. Have to trace the power wires out and see if any are chaffed.
Thanks Brother best one on TH-cam!!
You're welcome!
@@farmboy30117 you got me back on the road ! Thanks again!
I have a 1991 k1500 5.7 did a complete tune up except coil, ran great for 100 miles, now experiencing a flat out no power situation, runs rough idle and can not pull a hill or gain speed at all except over time. I can put my foot into it and sometimes it will act normal until I take my foot out of it but than it acts like not running in all cylinders. Oh yes revolution the throttle body as well thanks Don
I have a 1993 GMC 350 TBI that has fire to the coil and to where the coil wire plug’s in to the distributor cap but it is not going through the plug wires what could be the problem with it I have put everything new in the distributor and coil area
Can you tell if a 95 to 93 4.3 will go in a 81 4.1 without any problems
Could that why effect it on start up? I had to change my oil pressure sending unit and when I put my distributer back in timing was right but on start up it wants to die right away but if you give it alil gas and let it idle at about 2000rpm for about 30seconds then it's okay.
When you timed the distributor, did you unplug the wire so that the computer wouldn't effect the timing? Not sure, but it sounds more like a problem with the Idle Air controller.
No I didn't not unplug that thing. I had no idea about that plug until I watched this
how does the ignition control relay that is mounted next to the map sensor on the bracket come to play in this system
That's called esc module.
does it control timing due to knock signals
@@randy1ization these trucks do have a knock sensor on the block down low by the starter motor if I remember correctly and I believe you are correct in that the esc module uses the signal from the knock sensor. Esc module was eliminated in a later year in favor of a different way of processing knock signal. Think it was when they changed from ecm to pcm. Have had 2 with esc module and no problems. Have had problem with knock sensor though. GMT400 forum has lots of info on this.
Mine is not getting fire and I replaced the coil and the ignition module and all the point of contact are clean....
Check the power and grounds going to the distributor; if they are good, then most likely it is the pickup coil inside the distributor.
i have an unrelated question. i have same setup, recently had to replace ignition module under distributor cap. its run fine for a while, until starting up a hill the other day and all of a sudden got a loud rattling clanking noise from engine, and loss of oil pressure down to half (20) instead of 40. any ideas? the top side looks good all rockers move good, bottom side looks okay as far as i can tell, didnt get anything out of oil pan. whats your suggestion
Doesn't sound good. Loss of oil pressure sounds like a clearance issue. Maybe spun bearing? I'd definitely want to pull a couple of bearing caps off and look. Good luck.
Is there supposed to be battery voltage from the coil to the icm? My 1991 chevy 5.7 decided to not start last night. No spark. Replaced the icm hoping that would solve it. Now I'm stuck.
Me too bro did you figure it out
@@Michael-wk4yo Pickup coil in distributor.
@@Michael-wk4yo Kind of funny this came up. Last few week, my pickup was running like crap. Getting crappy fuel mileage. Apparently I didn't put loctite on the distributor bolt when replaced the distributor. It backed out and slowly spun my distributor. If your pickup coil is bad and you replace your distributor, make sure you use loctite on that bolt! Good luck!
not sure how to test this type of coile either boss
Thanks for info, trouble with my 89 tbi also.
What would be blowing a ignition module? I've had to put three in my 91 gmc 2500 sierra just dont know what it could be.
Heat kills them more than anything. First though, always buy from a quality auto parts store like NAPA. Don't buy them from Autozone, I've seen multiple failures with those. Next, always use heat sink paste and make sure the heat sink is clean when installing.
i have a 1990 chevy blazer 5.7 k5 i been having a miss in thengine n a hesitation when I press the throttle ive replaced cap,rotor,wires,plugs,coil,n ignition mogel n i replaced the whole distributer n still has the hesitate n miss been hoin on for a few weeks but now when I drive it for over a half hour or more it starts to bog out n backfire then shut off but starts back up and running it will do this a few times then i gota let it sit for bout 20min then sometimes it will start back up......help
+Edwin Padilla You didn't mention a check engine light, so all the sensors are probably ok. Looks like you've ruled out the ignition system, so one thing to check is a clogged exhaust (usually the catalytic converter), too much back pressure can cause strange things. If that isn't the issue, I'd look at the fuel system and make sure your fuel pressure is adequate. Hope this helps and good luck.
I have a 1990 k2500. It starts and runs fine but if you've been driving it for a while (maybe over 15 to 25 minutes) and then turn it off it then won't start again for a while. If you only drove it for a few minutes then it's fine. Then you can shut it off and turn it back on as many times as you want. But if you had ran it for a while and turned it off it won't start until you've waited 15 or 20 minutes. I can't figure out why. Anyone have any suggestions?
You can narrow it down to fuel or ignition by checking the spark next time it won't start. Could be vapor lock or an ignition part getting too hot. Since (I assume) it'll run fine as long as you don't shut it off, it probably isn't the fuel pump.
@@farmboy30117I'm pretty sure it's an electrical issue. Possibly in the ignition. When it doesn't want to start it doesn't crank at all. You turn the key and the gauges go up and down like normal but that's it. So it's not a spark issue. It acts as if you're not holding in the clutch. That's why I bypass the clutch safety switch but it's still doing it.
And thank you for your reply.
@@thejohn6614 My first thought is that the starter (or solenoid) is getting hot and not working if it won't crank at all. Is the exhaust factory manifolds? It'd be a pain, but I'd try to take a test light the next time it won't crank and see if you're getting power at the starter or starter solenoid.
@@farmboy30117 it was just not starting and I checked the stater and it was getting power but then it started immediately after. I'll check again next time it does it.
My Chevy Caprice 305 has no power when I put in fresh battery. What should I do?
Correction I don't have that clip ur talking about. I ha e the bigger squar one that holds a fuss
your a good man to help people God bless u sir
Thanks Luke!
What is the tack that the white wire is connected to
I have a 1991 chevrolet k1500. I changed my throttle body gasket and started the truck up and noticed a minor leak so I shut the truck off. After I tightened the hose I went to go start the truck again and had no fire. I changed the cap and rotor and cleaned the module but still have no fire. Having trouble find the brown wire but I was wondering if you may have an other idea to why I would not be getting fire?
On the side of the coil where one wire is bigger than the other, where is that little white wire supposed to be hooked to?
I believe the white wire would go to a tachometer.
I have a 1989 k1500 5speed and when I unplug wire and run icm it idles amazing but when the pcm tried to idle the truck it just dies and looped and I replaced ecm and prom, and egr, iac, map, tps please help
It also will start fine it just won’t idle
Might be a little late but it sounds like you’ve replaced all the usual suspects. Since the icm only cares about initial timing I would say your distributor is good. I would double check that initial timing is correct because from what I’ve seen the pcm really picks up the advance on timing.
I have a 89 Silverado old truck just passed inspection the next day I tried to start it and it started to crank then nothing. I've changed battery cables but I'm not a mechanical person so idk what to look for??
Duane, to be honest, there's a lot of things that can cause one not to crank. I'd recommend finding a local shop that you can trust to diagnose it. Some things are: low battery, bad starter, bad starter solenoid, bad ignition switch, broken wire, etc.
farmboy30117 return work. I never had a cavity till I went to a dentist
Good info. Thank you. I replaced the complete distributor,coil,cap,rotor,plug,and plug wires. Set timing and started up. Set base timing. Shut off truck and will not start back. Any ideas ?
Yea I change fuel pump ,injecters,ignition module , thinking it was that . nothing so then we went and check the grond on the injecters and no spry so that's the issue . I tested it by touching on any ground and spayed.. but how can I fix this problem... i really appreciated your help ...
Sounds like it isn't getting a ground signal from the computer. Might be a bad connection, wire, or PCM.
solid angel the ignition module can go bad to where it still has spark but doesn't send a signal to the ecm telling it to power the injectors.
solid angel did u find out whats wrong ? i have same issue. lots of new parts pump. injectors. distr. n ign. all of a sudden i crank and no spray whats going on?
Your problem is the computer
I have 94 GMC tbi 4.3 v6 vortec, was driving it, shut down like u turn key off no back fire, pop, no noise, I've checked it no spark, will crank but want start, what's my troubles, also have just replaced cap button an wires (+spark plugs) took ingintion modugel off had it checked an was good
I have a 89 suburban, the service light comes on it runs great, the light goes off it runs like crap. Spark knocks, pops and cracks, and u can smell its flooding out. Whats ur thoughts
Sounds like it's going into a default mode when the light is on. Need to find the code to see what sensor has gone bad.
@@farmboy30117 code 42, I changed out icm under the distributor and the light stayed on for about 2 weeks and ran great it it started shutting off again
Hey regarding that wire that isolates ignition from ECM...I have a 1991 Chevy 1500 and there's a plug there but it's white with black stripe. I unplugged it and tried to start but still no start. My issue is either ECM, ignition module, or pickup coil.
I wish I could post a pic of mine. It's in the same area you pointed to but is a different color.
I've heard they are in different areas depending on the year.
i have a 95 Chevy 1500 5.7 with a hesitation stumbling problem, changed out EGR valve etc, runs rough codes say running lean!
any ideas?
@Ricky definitely most likely cause of lean exhaust.
I m having a problem it seems like I don't have power from clips to the injectors for my gmc 1995 1500 z71. I changed my coil,module in distributor and and injector rebuild kit and no gas coming out injector. I hear gas pump cleaned fuel filter and thinking maybe change relay switch fuses are all good I'm stuck
So you probably have a fuel or ECM or Injector issue. (1) Without a fuel pressure tester, it is difficult to determine whether the fuel pump is producing adequate pressure. (2) The pink wires going to the injectors are coming from ECM1 Fuse (20 Amp) and should be hot in run or start on ignition key. Make sure you have power here with a test light or multi-meter. (3) The dark blue & dark green wires come from the ECM which provides a ground path (or ground side switched) to operate the injector solenoid. With no ground supplied from the ECM, there will probably be residual power on those wires. If you supply a ground to the blue or green wire, the injector would spray (assuming it has power from the fused wire and fuel pressure). It is difficult to see if the ECM is trying to operate the injector without a noid light or a special test light because it pulses so rapidly. (4) Check power and grounds at the ECM. You can do a Google Image search for "1995 Chevrolet Silverado wiring diagram" (AutoZone has a good one) that will show where to look for power and grounds to the ECM.
thanks merry Christmas I will do exact and get back to you from Hawaii Oahu aloha
Hi ... have a 95 chevy c1500 no spark or fuel change the coil and pickup alone with the module and the same result
Thanks for sharing the details.
I have a 90 chevy 1500 carberator parts were stolen with truck recovered vechile and finally back together all parts have been replaced any ideas I have a truck now no crank no start no click don't hear fuel pump kick on as well seems like something not powered could starter and solenoid not connected right cause problems
I'd suspect something wrong in the ignition switch.
Hello, I'm attempting a MSD Streetfire HEI distributor, I ran a pigtail for the coil, but how do I connect the 4wire harness for TBI pulse? Stock distributor is 2plug, and this new distributor only requires 2pin in?
I've never done a swap like that before, but is the HEI distributor computer controlled or vacuum advanced?
farmboy30117 The stock is an 8 pin controller, electronic controlled, and the new streetfire is a 4 pin, vacuum advanced. I just need a signal to pulse the injectors. Will the "B" bypass pin provide timing pulse to injectors?
I would contact MSD and see what they have to say. I have no idea.