Debunked - Dodge Fuel Synchronization - Part 3 (Whoa/Not What I Expected)
ฝัง
- เผยแพร่เมื่อ 18 ต.ค. 2024
- In this video I show a 1998 Dodge Magnum 360 running in slow motion with noid lights plugged into injector connectors for cylinders 1 and 5. I wanted to use cylinder 6 but it was on the other side of the engine and wouldn’t be seen. The intent was to show that when the cam sensor was disconnected the engine would switch from sequential fuel injector timing to batch fire wherein all 8 injectors fire at the same time once per engine revolution. But the video shows that the engine kept running with sequential injector timing even though there was no cam sensor to time the injectors. What the video doesn’t show is that if the engine shuts off it will not restart without a working cam sensor. This is poor engineering because it makes the engine less reliable in the event of a cam sensor failure.
But the take away from this video is that my claim that the cam sensor is not used to time the injectors is bolstered by the fact that the engine continues to run with the cam sensor disconnected. The cam sensor initially enabled sequential fuel injection using the crank position sensor and the engine continued to run using the crank position sensor after the cam sensor was disconnected. This is more evidence that the cam sensor is not used to time individual injector firings. It only enables the pcm to identify the location of the crank sensor and then the crank sensor is used to time injector firings.
EDIT: I never got around to making a part 4 video. But I found a video that covers what I was going to talk about anyway. It’s called rotor phasing. I can’t explain it any better than this video does.
• 🛠 Rotor Phasing Explai...
He starts talking about rotor phasing at the 2:38 mark.
I feel you brother. Trying to figure out what engineers do as to the big 4 is beyond explaining. Nowadays the so called Techs at the dealer just read out of a book.
Us Mechanics working on multiple platforms have to think as yes reengineer what the oem did, just to troubleshoot an issue. I am a diesel guy mostly heavy equipment and Class 8 trucks. I don’t do petrol/gassers unless it my own families vehicle.
I love it when us lowly mechanics not for pay figure out certain fails in systems those college engineers paid so dearly for as to education. Well done a good video.
Tomorrow I will try and box in when the injectors are firing using an idea I had today. GM fires them at 300 degrees crank rotation but not sure if Dodge follows suit. I think I can show that they fire between 260 and 330 degrees after TDC on the power stroke. Watch for the video on that.
Look forward to the video
Not for nothing but the system is no different than say a 7747 gm computer that fires either batch injection for individual cylinders or for the older TBI units . The cam sensor could be completely eliminated, just takes a few extra rotations for the crank to pick up the proper cylinders . Many use it with a cammed up engine and to initially build oil pressure . Good videos. Informative for those who can follow and understand.
The 7747 was not used for any batch multiport systems. It was TBI only which was alternate fire. There was also never a 7747 used with a cam sensor. Cam sensors didn’t come around until 1996 in trucks. I think the Grand National and maybe some Cadillacs used cam sensors in the 1980s. There is an aftermarket product that used a 7747 for multiport in batch fire mode. That product is “dynamicefi”.
I just completed a big job on a 5.9 magnum, I am glad I watched your video’s before putting it together as one of the parts I replaced was the distributor since the shaft etc and I was a victim of the fearmongering due to the “fuel synch”
I found your analogy of the gm 4.3 dist to be spot on, it is even simpler with this distributor since it has a flat shaft and you don’t need to consider the gear travel as it engages to the cam. It is either correct, or 180 degrees out. I completed replacing a host of seals and gaskets in the engine, placed the dist to point to the #1 terminal and when I turned the key it started instantly and runs really quite well, however I did end up with a check engine light and a code p01391 - do you think making small adjustments to the distributor position would change that, or should I have someone attach a scan tool to it, I only have a scanguage I don’t believe it can show realtime pods
You said you installed a new distributor. I would put money on it that the distributor has an aftermarket cam sensor that is intermittently defective. If the engine runs at all the fuel sync is fine. The code is for an intermittently bad cam or crank sensor so I would install brand new crank and cam sensors of Dodge mfgr.
@@moccasinmarine thank you for your reply. I did install a new distributor as the one that was in there had alot of corrosion etc. I ordered my parts from rockauto so the actual mopar brand was not availabe, the one I used was wai global, I chose that brand because I used one in my 4.3 chev a few years back and am happy with it (especially since it has a metal housing unlike the gm plastic one). The durango with the 360 magnum had been sitting for a few months as I disassembled it, located parts etc so once I was done with it I initially removed the fuel pump relay and cranked the enging over for some time to build some oil pressure, with the relay reinstalled I primed the key twice and had 50 some psi of fuel so I turned it over and it started instantly and runs very well even driving it all runs very strong - since then I have been messing with it to make sure all is good with leaks etc and today when I started it that engine light and code are no longer there so I don’t know if it had to relearn the cam position or what but all is great with it now. The distributor I bought actually came all assembled with a stick on seal on the position sensor with their phone number support line etc as their warranty may be void once the seal is torn, their distributors seem of decent quality.
I am very happy that you posted your videos and I feel you have a good understanding of the system and I felt much more confident to go ahead and swap the distributor since all the bs I had hears about the fuel synch had me gunshy. The fact that you compared it to the 4.3 gm really hit home with me as I had done mine a year and a half ago and really struggled with the installation of that one since all you really have to do is make sure the rotor is at the number 1 firing position and the computer does the rest. It just seems too simple to me having never done distributors on fuel injected/computer controlled engines before so timing lights, adjustments afterwards etc.
When I do “tune ups” now I always just replace the distributor assemblies as opposed to cap,rotor,pickup coil because it is usually only another few dollars to just get the whole thing and then you have a new shaft/housing to boot.
Thanks for your videos I have watched quite a few.
This engine only has 115000 km on it, I disassembled it because the lower plenum plate on the intake had a failed gasket and the intake/timing gaskets had failed also - kind of a quirky setup that engine is
Just watched this video and I’ve come to a conclusion: you have misunderstood what people mean when they say the cam sensor position is for injector timing. We’re not saying it’s variable during operation like the ignition is. It’s a mostly static setting. I say mostly because if you actually go through the DRB3 setting process, if you set the fuel sync to +4 for example, it won’t just stay +4. In real time it will change quite rapidly. 43422243344334556554444356444345444344. Alot like that. But that’s as close as static as you can set it just due to tolerance. But that’s what we call +4. So now that we’re set to +4, the injectors are just going to 4 degrees of distributor rotation sooner than they otherwise would when set to the OE spec of 0 degrees. This is regardless of rpm, load, ignition timing, etc. It’s like locking out the distributor in a carb application and running 30 degrees all the time. This is why it continues to operate fine when disconnected yet refuses to start when shut down. Without that setting it IS as you have said and the crank sensor doesnt know where in the 720 degrees it is. The cam sensor needs to show where cylinder 1 is and when and once accomplished the cam sensor doesn’t really matter. The fuel sync is set in the pcm.
Once again you are completely not understanding the point of my videos. The fuel sync has nothing to do with injector timing or cam timing. All it does is help the PCM identify where the crank sensor is in a 720 degree cycle. And by the way the reason the fuel sync setting jumps around is due to the slop in the timing gears and chain that I mentioned in the video. I’ve got another video coming that will explain why you need to set fuel sync at zero or best you can at zero and nothing else.
@@moccasinmarine I think you're right. My guess is that the PCM determines what rotation you're on right away at, or after startup; thus if you pull the plug on the cam sensor, it doesn't matter..
Pretty sure the cam sensor in the dizzy is only used during start up. I just know it has to make a full turn before she will light. Then I think it's replaced by the crank sensor for timing. Could be totally wrong about all of that.
It is. Basically the same way the old batch fire computers of the 90’s for GM worked. They will crank and start with just a crank sensor. Takes a few revolutions of the starter until the crank sensor picks it up but does run . Using. A 0411 computer on a 5.9 just because the tuning software is much more usable and much much cheaper
The video made since but I need real time fix ..my 5.9 litre gasoline engine runs good,idles smooth but has lost a lot of power well before I hit 254000miles. My gut tells me it's the slop in the timing chain and the distributer .maybe not ! However if I run 93grade unleaded I get additional power back but not near what it had when below 200,000.miles it's been a slow deterioration.thanks for the Video I'm a bit late to watch .
Check your catalytic converter. It clogs up slowly over time.
Also those are notorious for leaks on the bottom of the intake where a plate is bolted from underneath, the gasket between them fails and it leaks vacuum and draws oil vapors etc into the cylinders - if run this way for a long time, the catalytic converters can get clogged. I am in the middle of this plenum gasket repair right now, not exactly a fun project
what is that for lights an have you a link from this tool