LOL, buy a drink and the truck sitting there running. Mine was dieseling today, walked in the house to grab a knife and the damn thing was still running. I had to adjust my idle curb screw, it was too high. Great info Tim!!
Thanks for the refresher .. i just started my 460 ford engine up and i built the motor to really move .. it has higher compresion and it dieseled when i shut it off .. i know its got old gas but it always has had bad backfeed from my electric fan .. i couldnt quite remember what caused dieseling . Id bet this video has solved my problem 100%
I had a simple fix for my diesling motor. When I was parking the vehicle and come to a stop, you know with the vehicle in drive and my foot on the brakes, when I shift into park the motor revs up because it is no longer under load (normal). It would diesel if I tried to shut the motor off right away, so I figured out to let the motor idle with the transmission in park for 3-4 seconds before shutting it off!
Arter watching your video I remember adding a 4 wire harness to control shift my 4l80e transmission I will add what's called a Short Stop that let's voltage travel one way Thanks for sharing!!
Good stuff. I've been battling this issue the last several months with the 406 in my Biscayne. I've got good gas. Timing's good. No electrical issues. It shuts off clean if I haven't been driving for an hour or more. But it does diesel after it's been running a good while (1-2hrs). So I'm leaning towards carbon build-up since I've got a big ol' carb on there and it's pretty rich.
Carbon on top of the piston will do it everytime on a SBC...acts like a glowplug in a diesel engine....you can pour a little trans fluid down carb while running...or pour small amounts of water in carb while running to bust the carbon off top of piston
Here are some diagnoses and fixes for stuff not mentioned in the video. I can also confirm everything in this video is 100% true, this guy knows what he's talking bout. *Dirty Intake Manifold* Old cars that have never been internally maintenanced in the last 5 years may have excessive carbon build-up in the Intake Manifold. This is very common if your engine is carbureted. I like to call it gunk. This gunk ruins your performance as it may catch gasoline, lowering the amount of gasoline going in to the cylinders. But it can also hold gasoline for the engine to whiff on when the carburetor stops supplying gasoline. This can cause the engine to diesel since a small amount of fuel is still getting in the cylinders. THIS CAN ALSO BE MISTAKENED BY A DIRTY OR BAD CARB. Diagnose: If you've ever had to replace your Valve Cover Gaskets to a bad oil leak, If your engine hasn't been maintenanced in the last 5 years, you had to replace your PCV Valve due to it being stuck open and sucking oil, looking down the carburetor with the doors open to see if it's gunked up or excessively black Fix: Taking off your Intake Manifold and manually clean the ports with brake cleaner. While you're at it, get it a new gasket and china walls. *Excessive Vacuum Leak* An engine has a vacuum system to allow vacuum actuated devices to function (such as the HVAC System or Brake Booster). This is a SEMI-SEALED SYSTEM. The only vacuum leak should be the PCV Valve. The rubber tubes that we pull vacuum through will rot out, go bad, or rip/crack. Vacuum is created within' the intake or carburetor when a Piston pulls gasoline down in to the cylinder. Diagnose: If you have a PCV Valve, or the hole where is supposed to go on your Carburetor, take it out of the Valve Cover and cover it with your finger. If the RPM's of the engine do not drop (aka, it does not slow down considerably) then there is possibly a vacuum leak in your engine, which will cause dieseling. Fix: Find where the vacuum leak is occurring. The only two places where you can get vacuum is in front of the Distributor connected to the Intake (its a threaded piece called a vacuum tree) and the Carburetor. A vacuum leak can occur when (1) something in the vacuum system isn't plugged (2) a device which requires vacuum is leaking and should be disconnected and repaired, this followings a hissing or sucking noise (3) The Vacuum tree on the Intake is not sealed properly. *(BAD) Head Gasket Problem* It is known that when a Head Gasket is bad it will cause Coolant and Oil to come in to the combustion chamber. But it can also cause small amount of gasoline to enter the cooling system or oil. It can also cause excessive pressure in the cooling and oil system from the explosion of the gases which can recoil and push the cylinder back down. What could be happening is that the coolant or oil is so contaminated, when it comes in to the cylinder; it may prematurely explode. Diagnose: Go to your exhaust, and get a good whiff of it (or both if you have a dual exhaust). If it smells sweet or like a sweeter gasoline smell (It will take your breathe away a bit) or is blowing slight/cloud like white smoke out your exhaust, excessive water draining out your exhaust after running for a while. Fix: Head Gasket replacement, You can also attempt to use head gasket sealer in the cooling system (I've heard this works, but only a temporary fix)
I am having a terrible dieseling issue with my 350. I tried adjusting fuel air, fast idle,and timing. I’ve gotten so frustrated with it I honestly just put the whole project to the side for months. I’d love to get back to a square one situation but I’ve adjusted and tickered with so many things at this point. I don’t know if you could help at this point but if you can that would be awesome!
I'm having the same issue with my 350, only got a couple thousand miles on new motor. Can't get motor to idle down and it deizals when shutting off... 🙄
@@georgewilkinson1068 I replaced the carb with a new one. And the high idle went away. But the dieseling stayed. I eventually realized I must have gotten bad gas Because I switched to premium and it went away.
I've got some dieseling issues myself, '89 Mustang Hatchback w/ a 347 Stroker. I'm no mechanic, but it was a good deal and couldn't pass it up... Will try some info in this vid, but any info would be awesome! **Bought from a local dealer, did not build myself**
Ive tried like everything and it still happens every now and then. A guy told me some of them just do it. Do i need to worry about this issue if it just happens sometimes?
Not dieseling related but maybe you know what I can do to solve my problem . I've got a k2500 obs with the 5.7 in it, I can put a new battery in it and if I don't disconnect the battery every time I get out the next day it's dead . How can if find what's drawing on it ? Thanks for any and all help
@@sheldonstewart70 best thing to do is hook a meter to it and start pulling fuses until you find the draw. A lot of times the glove box light on those trucks stay on.
My Nissan B13 doesn't diesel when it's cold, in fact it stalls out until it warms up, and I suspect has some carburetor problems causing problems at low rpm. But soon as the engine is hot and I shut it off it diesels. Yea maybe it's my choke staying on.
yes sir you are 100% right I might just need to add old militari vehecels hade fuel/air compensators and moisture/oil seperators new studis show bacteria eating oil exist aperantli it has some thing to do with out side organic gas with chemical gas mixture when ever I drive by centrain forest type or surage is close to my house if that back fead is present or dual relays arc due to internal diodes failure that staff gas gets sucked in the engine it floods the engine at centrain times in the morning aperantli it has to do with companion cilinders valve clearance and those engines cinde of try to act as hot bulb,hit and miss or flame liker engines some times they combine intake fiering with combustion fiering or exaust fiering wuld work also if the spark plug leads wuld get swaped around or turn distributor on warm engine 180° out of phase fiering . So preaty much anoying effects but usefull for fuel economi in some of my videos its actuali shown perfect diseling on carbureted engine its old Opel from the 80s engine its tipical GM and yes like you told terribel wire harnest evry thing arcs stuck buzzing horn,2or more relays interact with ich other,no diode on dashboard voltage stabiliser,no diode on delco 12si field wire,no ballast for xenon bulb who look like wacum tube ,organic coolant electrolusys,oil pan leaky driping at exaust pipes,leaky carburetor,or in general magnetised engine for what ever reason all springs in the car stiffen or soften for some reason including head valves,fuel reservoir cap,coolant thermostat,suspension,well not to mention those odd s/r starter motors are strange as well so my car is basicali haveing bacteria eating oil in crank shaft old lubrication oil bade fuel like you told and leaky mechanical fuel pump engine works great nothing wrong with it but hard to start it when its cold expeciali if distributor is to far advanced so my engine uses 2 stroke port fuel feading and pre heating so on my video you can see barreli any fuel is drawn from fuel filter I ques it is safe to asume it is some sort of low speed high torque low speed engine probably hot bulb,hit and miss or carbureted disel engine . I wuld recomend to use cloosed loop alternator circuet or dual voltage regulators for low and high speed engine aplications some delco alternators 12si have low rpm regulators the starter motor needs reduction gearing and probably dual baterry system or baterry/capacitor bank system wuld by great to have that thing can easely coppy older engines they use still oil splashing wia crank shaft and gear driven oil pump so under around 2000rpm safe to drive them how ever cloosed loop thermostat is requared ,haveing gages that cant react to static and preferably manuali engage thermostat ,ignition timing and variabel carburetor jets ,biggest problem are gaskets by those cars they need high compresion gaskets bether variabel transmision perhaps thicker piston rings and maybe braket for crank shaft holder evry thing ells is same just like by disel engines .Great video sorry my gramar is terribel. Just put lot diodes in that thing and seperatly build ich circuet I wuld use only leads insted chassys ground those cars havr terribel rosting problems virtual ground might save peopel from lot trobel .When that strange staff starts to happen normali the brakes get stuck they also have metalic springs or to much preshure and heat acidic solution might eat brake master cilinder rubber so it wuld by wise to put on cilinder preshure regulator or bypass all that crap and use external electric pump in case of emergency if engine fails by carefull thats bade shit there when that happens I wuld also advice you to remove stering lock mechanism for key switch that culd save your life probably Im my self decided to use on my front wheel car rear differential from similar car who is rear drive and place magnetic brake on rear differential for safti reason .I personli experianced brakes failure due to that static shit those effects are usefull but other systems in the car get also effected so by carefull .
don't allow your engine to diesel, it will damage the internals Shut it off in gear to smother it until you figure out the problem. Check your timing, lower your idle, pour Seafoam down the carb to burn off carbon deposits, check spark plug gaps. Get everything back to the factory settings. Over the years, they can get out of whack from previous owners and mechanics monkeying with them.
LOL, buy a drink and the truck sitting there running. Mine was dieseling today, walked in the house to grab a knife and the damn thing was still running. I had to adjust my idle curb screw, it was too high. Great info Tim!!
Thanks for the refresher .. i just started my 460 ford engine up and i built the motor to really move .. it has higher compresion and it dieseled when i shut it off .. i know its got old gas but it always has had bad backfeed from my electric fan .. i couldnt quite remember what caused dieseling . Id bet this video has solved my problem 100%
I had a simple fix for my diesling motor. When I was parking the vehicle and come to a stop, you know with the vehicle in drive and my foot on the brakes, when I shift into park the motor revs up because it is no longer under load (normal). It would diesel if I tried to shut the motor off right away, so I figured out to let the motor idle with the transmission in park for 3-4 seconds before shutting it off!
Mine too
I had one stick shift car and when it did that I used to try to make it go in first. It would start to rock a little but then quit.
Thank you very much for your knowledge and helping folks with problems with their trucks! I wish that I was as smart as you are my friend!
Thankyou for your vids. I enjoy them. Been working on this old iron for over 40 years!
Arter watching your video I remember adding a 4 wire harness to control shift my 4l80e transmission I will add what's called a Short Stop that let's voltage travel one way Thanks for sharing!!
Good stuff.
I've been battling this issue the last several months with the 406 in my Biscayne. I've got good gas. Timing's good. No electrical issues. It shuts off clean if I haven't been driving for an hour or more. But it does diesel after it's been running a good while (1-2hrs). So I'm leaning towards carbon build-up since I've got a big ol' carb on there and it's pretty rich.
Definitely could be getting to much fuel and the engine is just burning raw fuel,
Carbon on top of the piston will do it everytime on a SBC...acts like a glowplug in a diesel engine....you can pour a little trans fluid down carb while running...or pour small amounts of water in carb while running to bust the carbon off top of piston
Here are some diagnoses and fixes for stuff not mentioned in the video. I can also confirm everything in this video is 100% true, this guy knows what he's talking bout.
*Dirty Intake Manifold*
Old cars that have never been internally maintenanced in the last 5 years may have excessive carbon build-up in the Intake Manifold. This is very common if your engine is carbureted. I like to call it gunk. This gunk ruins your performance as it may catch gasoline, lowering the amount of gasoline going in to the cylinders. But it can also hold gasoline for the engine to whiff on when the carburetor stops supplying gasoline. This can cause the engine to diesel since a small amount of fuel is still getting in the cylinders.
THIS CAN ALSO BE MISTAKENED BY A DIRTY OR BAD CARB.
Diagnose: If you've ever had to replace your Valve Cover Gaskets to a bad oil leak, If your engine hasn't been maintenanced in the last 5 years, you had to replace your PCV Valve due to it being stuck open and sucking oil, looking down the carburetor with the doors open to see if it's gunked up or excessively black
Fix: Taking off your Intake Manifold and manually clean the ports with brake cleaner. While you're at it, get it a new gasket and china walls.
*Excessive Vacuum Leak*
An engine has a vacuum system to allow vacuum actuated devices to function (such as the HVAC System or Brake Booster). This is a SEMI-SEALED SYSTEM. The only vacuum leak should be the PCV Valve. The rubber tubes that we pull vacuum through will rot out, go bad, or rip/crack. Vacuum is created within' the intake or carburetor when a Piston pulls gasoline down in to the cylinder.
Diagnose: If you have a PCV Valve, or the hole where is supposed to go on your Carburetor, take it out of the Valve Cover and cover it with your finger. If the RPM's of the engine do not drop (aka, it does not slow down considerably) then there is possibly a vacuum leak in your engine, which will cause dieseling.
Fix: Find where the vacuum leak is occurring. The only two places where you can get vacuum is in front of the Distributor connected to the Intake (its a threaded piece called a vacuum tree) and the Carburetor. A vacuum leak can occur when (1) something in the vacuum system isn't plugged (2) a device which requires vacuum is leaking and should be disconnected and repaired, this followings a hissing or sucking noise (3) The Vacuum tree on the Intake is not sealed properly.
*(BAD) Head Gasket Problem*
It is known that when a Head Gasket is bad it will cause Coolant and Oil to come in to the combustion chamber. But it can also cause small amount of gasoline to enter the cooling system or oil. It can also cause excessive pressure in the cooling and oil system from the explosion of the gases which can recoil and push the cylinder back down. What could be happening is that the coolant or oil is so contaminated, when it comes in to the cylinder; it may prematurely explode.
Diagnose: Go to your exhaust, and get a good whiff of it (or both if you have a dual exhaust). If it smells sweet or like a sweeter gasoline smell (It will take your breathe away a bit) or is blowing slight/cloud like white smoke out your exhaust, excessive water draining out your exhaust after running for a while.
Fix: Head Gasket replacement, You can also attempt to use head gasket sealer in the cooling system (I've heard this works, but only a temporary fix)
4:00 Mark, Flash point for gasolie vapors minus 45 degrees F. Autoignition Temperature: 536 Degrees F.
I had this on my Volvo 344 and couldn't for the life of me figure out why, now 13 years later I know!
How can I stop electrical feed back I think I’m getting it with my electric fans
Can too much oil cause this?
I changed my oil and it didthis for the first time. it’s about quarter an inch over full (added 5qts, 400sbc)
I am having a terrible dieseling issue with my 350. I tried adjusting fuel air, fast idle,and timing. I’ve gotten so frustrated with it I honestly just put the whole project to the side for months. I’d love to get back to a square one situation but I’ve adjusted and tickered with so many things at this point. I don’t know if you could help at this point but if you can that would be awesome!
Did you fix it eventually? Do you happen to have a high idle?
I'm having the same issue with my 350, only got a couple thousand miles on new motor. Can't get motor to idle down and it deizals when shutting off... 🙄
@boerenbrommer no I never have fixed it. I eventually moved out of state and it just sits now.
@@samwaldfogel2246: Did you try "blipping" the throttle to slow down the idle speed?
@@georgewilkinson1068 I replaced the carb with a new one. And the high idle went away. But the dieseling stayed. I eventually realized I must have gotten bad gas Because I switched to premium and it went away.
I've got some dieseling issues myself, '89 Mustang Hatchback w/ a 347 Stroker. I'm no mechanic, but it was a good deal and couldn't pass it up... Will try some info in this vid, but any info would be awesome!
**Bought from a local dealer, did not build myself**
Definitely start with timing and good high octane fuel
Hey man my 383 Chevy motor keeps doing that after it heats up . I've un plugged the wire to the
Did the carb swap fix it ?
Ive tried like everything and it still happens every now and then. A guy told me some of them just do it. Do i need to worry about this issue if it just happens sometimes?
What do you need to look for in terms of choke???
Just make sure that it’s set correctly
@@gmtim3840 do you mean open when should be open and closed when should be closed? Or something more sophisticated?
Not dieseling related but maybe you know what I can do to solve my problem . I've got a k2500 obs with the 5.7 in it, I can put a new battery in it and if I don't disconnect the battery every time I get out the next day it's dead . How can if find what's drawing on it ? Thanks for any and all help
Does it have anything aftermarket on it? Like lights,radio amp etc?
@@gmtim3840 I'm pretty sure the radio is the only thing aftermarket and maybe wiring for trailer
@@sheldonstewart70 best thing to do is hook a meter to it and start pulling fuses until you find the draw. A lot of times the glove box light on those trucks stay on.
@@gmtim3840thanks
What if it only does it when cold staring u crank it and had to turn it off and it diesels.. when fully warmed sometimes hard to start?
My Nissan B13 doesn't diesel when it's cold, in fact it stalls out until it warms up, and I suspect has some carburetor problems causing problems at low rpm. But soon as the engine is hot and I shut it off it diesels. Yea maybe it's my choke staying on.
I'm getting a new 350 small block swapped in my GMC Yukon.
yes sir you are 100% right I might just need to add old militari vehecels hade fuel/air compensators and moisture/oil seperators new studis show bacteria eating oil exist aperantli it has some thing to do with out side organic gas with chemical gas mixture when ever I drive by centrain forest type or surage is close to my house if that back fead is present or dual relays arc due to internal diodes failure that staff gas gets sucked in the engine it floods the engine at centrain times in the morning aperantli it has to do with companion cilinders valve clearance and those engines cinde of try to act as hot bulb,hit and miss or flame liker engines some times they combine intake fiering with combustion fiering or exaust fiering wuld work also if the spark plug leads wuld get swaped around or turn distributor on warm engine 180° out of phase fiering . So preaty much anoying effects but usefull for fuel economi in some of my videos its actuali shown perfect diseling on carbureted engine its old Opel from the 80s engine its tipical GM and yes like you told terribel wire harnest evry thing arcs stuck buzzing horn,2or more relays interact with ich other,no diode on dashboard voltage stabiliser,no diode on delco 12si field wire,no ballast for xenon bulb who look like wacum tube ,organic coolant electrolusys,oil pan leaky driping at exaust pipes,leaky carburetor,or in general magnetised engine for what ever reason all springs in the car stiffen or soften for some reason including head valves,fuel reservoir cap,coolant thermostat,suspension,well not to mention those odd s/r starter motors are strange as well so my car is basicali haveing bacteria eating oil in crank shaft old lubrication oil bade fuel like you told and leaky mechanical fuel pump engine works great nothing wrong with it but hard to start it when its cold expeciali if distributor is to far advanced so my engine uses 2 stroke port fuel feading and pre heating so on my video you can see barreli any fuel is drawn from fuel filter I ques it is safe to asume it is some sort of low speed high torque low speed engine probably hot bulb,hit and miss or carbureted disel engine . I wuld recomend to use cloosed loop alternator circuet or dual voltage regulators for low and high speed engine aplications some delco alternators 12si have low rpm regulators the starter motor needs reduction gearing and probably dual baterry system or baterry/capacitor bank system wuld by great to have that thing can easely coppy older engines they use still oil splashing wia crank shaft and gear driven oil pump so under around 2000rpm safe to drive them how ever cloosed loop thermostat is requared ,haveing gages that cant react to static and preferably manuali engage thermostat ,ignition timing and variabel carburetor jets ,biggest problem are gaskets by those cars they need high compresion gaskets bether variabel transmision perhaps thicker piston rings and maybe braket for crank shaft holder evry thing ells is same just like by disel engines .Great video sorry my gramar is terribel. Just put lot diodes in that thing and seperatly build ich circuet I wuld use only leads insted chassys ground those cars havr terribel rosting problems virtual ground might save peopel from lot trobel .When that strange staff starts to happen normali the brakes get stuck they also have metalic springs or to much preshure and heat acidic solution might eat brake master cilinder rubber so it wuld by wise to put on cilinder preshure regulator or bypass all that crap and use external electric pump in case of emergency if engine fails by carefull thats bade shit there when that happens I wuld also advice you to remove stering lock mechanism for key switch that culd save your life probably Im my self decided to use on my front wheel car rear differential from similar car who is rear drive and place magnetic brake on rear differential for safti reason .I personli experianced brakes failure due to that static shit those effects are usefull but other systems in the car get also effected so by carefull .
don't allow your engine to diesel, it will damage the internals Shut it off in gear to smother it until you figure out the problem. Check your timing, lower your idle, pour Seafoam down the carb to burn off carbon deposits, check spark plug gaps. Get everything back to the factory settings. Over the years, they can get out of whack from previous owners and mechanics monkeying with them.
How far away did you grow up from Blake Shelton? You sound exactly like him.
A long way, I believe he’s from Oklahoma lol