Possible ECM issues

[Takendad]

New here so haven’t read all the posts yet. I have a 1999 Dodge 3500 5.9 Cummins 24 valve. Truck sat for 12 years after my dads death. Been working on it for the last 6 months. New VP44, lift pump, fuel filter and so on. New turbo, APPS, all sensors and so on. My issue now is I can drive the truck as long and far as I want to, no issues, no power loss. As soon as I shut it off and I re start it after being off for 15 mins up to two hrs, it will run for five mins or so and just shut off. Won’t restart until it sits a couple of hours. I know this isn’t a good practice but tried it twice, I can put about 16 oz of water on ecm (not on wire harness) and wait 5 mins and it will start and run as if there was never an issue. Truck is stock and ecm is still mounted to block. Any thought? Thanks in advance!!

[Dieselfuture]

Welcome, 

All of us still have the ecm on the block, the fact that you dump water on it and it starts to work tells me there's a solder issue. From what we know earlier ecms weren't as strong built as later ones like 01,02 you could try sending yours in to have it repaired or try to find a used one and reprogram it to your trucks vin. I have to say usually it's the vp board that people dump water on to get started, not sure I've heard of ecm doing that, but what I've said is my guess. Someone will correct me, that's what we do best here is trying to get the best answers to the problem.

It would be a very good idea to do the WT mod and check your alternator for AC noise, that is 2 biggest electrical causing problems with these trucks and also rest of grounds and good batteries. 

After all these years we're still finding something to mod and improve, that's of course if you like to tinker with stuff. 

[Tractorman]

Good info from @Dieselfuture.  @Takendad, is it possible that you were unintentionally getting water on the PSG unit mounted on the VP44 injection pump while you pouring water on the ECM?  If so, it is more likely that you are having solder problem in the PSG rather than the ECM.

 

- John 

[Takendad]

I am very direct putting the water on the ecm, about 98% sure I’m not hitting the VP44 in anyway. I will try it again and make sure 100% that I’m not. I’m also gonna try the mod over the weekend. Of course anything can go wrong but VP44 has less than 100 miles on it, by the way truck has 113,297 miles on it. I found the list of reputable ecm suppliers and repair shops. I am a “diesel dummy” so all the help is very much appreciated!!

[wil440]

Good luck with the truck you came to the right place to get it all sorted out

 

As @Dieselfuture says... WT mod, check alternator for noise

Have you a scanner that can see live data or borrow one, check data on when running ok against when not starting, is there any fault codes....  preferrably scanned 

 

As the truck has sat for so long I'd be checking every ground on it certainly if sat outside, there is 3 grounds at and below the drivers battery, more than likely nothing to do with your problem but worth making good, I had a wiper/ turn signal problem a month or so ago, signal left and the wipers came on and stayed on until the turn was cancelled, I actually removed the holding nut and checked it out on the back of someone on here (thanks) and it looked ok so bolted it back up, after checking everything else I went back to that ground G100 in the schematic and dug into it, one wire in the middle of the bunch down to ONE strand and urinal blue corrosion all around it in the middle of the bunch.

Also do the PCM charge fuse that @Mopar1973Man figured out

They are great trucks but very electrically challenged, I don't even lift the hood (bonnet here in the UK) in the rain rather unfortunate really as we do get a lot of rain 

[Takendad]

Thanks for all the help, I’ve checked all grounds, wires but going to go over everything again this weekend plus try to do the WT mod. Thank you all for the information. I will let you know the final cause is so we can pass it on later if needed!!

[Mopar1973Man]

On 4/9/2021 at 1:53 PM, Takendad said:

Thanks for all the help, I’ve checked all grounds, wires but going to go over everything again this weekend plus try to do the WT mod.

 

Don't have to do the other grounds because the W-T mod will relocate the grounds. That would be a waste of time cleaning up the old ground to relocate to a new place which will force you to create a new clean ground. 

 

[wil440]

16 minutes ago, Mopar1973Man said:

 

Don't have to do the other grounds because the W-T mod will relocate the grounds. That would be a waste of time cleaning up the old ground to relocate to a new place which will force you to create a new clean ground. 

 

That needs a little more clarification to be fair, The WT mod relocates what the WT mod relocates, this is not all grounds and someone reading this could think WT done.... I'm good..... not so, there are more and depending on the problem as to where one needs to be looking.

The WT mod does take care of some very poor Dodge electrical design connected to very important  systems but 12 years parked anything could be corroded

[Dieselfuture]

WT came out of nowhere and vanished just the same after sharing with us his electrical knowledge. Hope he's doing good, I know he went through a lot after the fires @JAG1 drinks beer with him every night and keeps an eye on him, he also likes to drop bolts and nuts in random places 

[JAG1]

34 minutes ago, Dieselfuture said:

WT came out of nowhere and vanished just the same after sharing with us his electrical knowledge. Hope he's doing good, I know he went through a lot after the fires @JAG1 drinks beer with him every night and keeps an eye on him, he also likes to drop bolts and nuts in random places 

Yep, target practice time! That sofa ain't no good with a pair of these! 

[Mopar1973Man]

Next time I see you @JAG1 I'll drop an manifold bolt in your intercooler.   

[Takendad]

Update: Went through all wiring and grounds, haven’t done mod yet. Took truck for about a 25 mike ride and came back home, hit speed bump in parking lot a little faster than I guess I should have. Truck shut right off, drifted into parking spot. Still going to do mod, but now definitely leaning towards a bad connection in computer.   Checked every ground and wire and all connections from battery back. Bright side I put new headlights, fog lights ( not yellow anymore) and new led cab roof lights. 

Edited April 12, 2021 by Takendad

[Mopar1973Man]

On 4/11/2021 at 12:07 PM, wil440 said:

That needs a little more clarification to be fair, The WT mod relocates what the WT mod relocates, this is not all grounds and someone reading this could think WT done.... I'm good..... not so, there are more and depending on the problem as to where one needs to be looking.

The WT mod does take care of some very poor Dodge electrical design connected to very important  systems but 12 years parked anything could be corroded

Simple and main computers ground do not go to body metal in stock form. ECM, PCM, and VP44 are all on the passenger ground cable. After the W-T mod the computer will not be on the passenger battery but the gear near the VP44.

 

All other subsystems ground to body metal. Like ABS grounds near the driver side headlight.