Engine/Transmission (1998.5 - 2002) No start when hot, suspect VP44 Electronics

[jcoop]

Late 2001 2500
HO 6 speed 4wd
89,xxx miles
FASS rail mounted fuel pump
Gauges with Fuel pressure idiot lite.


Have to say that prior to fuel filter replacement I have had the same problem, but just an occasional skip then it would be fine.

Last week I changed the fuel filter and had to crack injectors to bleed the air out. Yesterday I purchased a trailer that was 100 miles away from home. Northern California summer with air temps high 90's. Drive over to seller of the trailer was uneventful. Took care of transaction and headed home, 15 min into return trip truck started to hesitate. Got off the main road into a parking lot. Pulled banjo bolt off of the VP44 and cycled it, lots of fuel. Hooked banjo back up, cracked #1 injector, lots of fuel. Fuel pressure idiot lite was off, could hear lift pump run normally.

Had around 1/4 tank of fuel talked to my mechanic and he suggested adding 5gal of fuel. Just then the seller called and said he forgot to give me the keys to the trailer. Told him what was going on and he brought me 5 gallons of diesel and the keys. Added the fuel, cycled the FASS a couple times, started rite up. Made a bee line for the fuel station and added 20 gallons.

Truck runs great for about 50 minutes / 45 miles, then same thing. Got off the freeway into a bus stop, this time totally dead. Before it would start and run for 5-10 seconds then die, this time it would just crank. This was around 4pm, the hottest part of the day.

Gave up and had buddy come get the trailer and towed the truck home.

This morning, started up no problem and let it idle for 10 min or so, smooth as silk.

Read codes yesterday
P370
P1690
P1691

Have looked them up and understand them.

My thought is that the electronics are heating up then die. After sufficient cooling they work again. Knowing what I know now I wish I would have had a can of the compressed air, I would have shot the VP44 cover and see if that would have cooled it down enough to get it running. Really think the transistor in there is dyeing of heat exhaustion.

Have seen a couple youtube videos of people taking a crack at replacing the transistor with minimal success. I have the skill to do the soldering and can take anything apart and put it back together.

My first choice would to purchase a new ecm for the pump or even a used one, then secondly give the transistor replacement a shot.


Any thoughts / suggestions would be appreciated, would rather not spend $1500 - $2k for a new VP44 when I feel the mechanicals are fine.


Thank you
John Cooper

 

[klcammie]

I've had the 1690 code before and it turned out to be my CKP sensor. Changed it out and no more codes. Don't think this is much help since you have two other codes that I didn't.

 

[jcoop]

The more I dig into this the more I think it's heat related. I wish I would have had one of those canned air dusters with me. A trick is to turn them upside down and you get a real nice cooling spray for cooling off electronics to see if that is the issue. May go buy a can and go for a drive in the heat of the day tomorrow. Will check with AAA and see if I have any more tows left though. Could be an expensive experiment if not.

John

 

[JR]

You can also pour water onto it and it won't hurt it. Obviously you don't want to douse a hot engine with a 5 gallon bucket but concentrating a slow stream onto the pump will give you a good idea.

Nobody sells individual parts for the pumps, only certified Bosch rebuild shops have access to such parts and they will sell you a pump all day long but no individual parts. Hate to say it but by the codes and symptoms your lookin at a pump. You can find a decent reman for around a grand if you install it yourself. I know it's not cheap, but not much is when it comes to owning a diesel.

 

[jcoop]

Price of admission to the Diesel world I suppose.

Just hoping I guess

Thanks for the info

John

 

[JR]

It would be interesting to see how your theory works out, it would eliminate any doubts you might have about spending that kind of money on a new pump for nothing.

Do you have a fuel pressure gauge or just the light? Even though I have a light, I never relied on them to tell me I have a fuel pressure issue. By then the pressure is too low anyway and the damage is being done if its run at that low of pressure for any length of time. I stacked a washer on top of my regulator spring to get a little extra pressure and run a steady 15-16 psi. I wired the idiot light up close to eye level so it would grab my attention if I didn't catch the gauge in the event of a problem but I do prefer the gauge to know what I am running at all times.

 

[jcoop]

JR,

Will see how brave I am later today, it took almost an hour both times. Maybe I will just let it idle with the exhaust brake on, that will heat it up.

I had a FP gauge to begin with, but I had to replace it three times. For whatever reason they just kept failing, that is why I went to the idiot light. So far that has been working good.

John

 

[SnoKing]

Mine started requiring a longer crank time when hot in the SW weather about 6 months before I got the P0216 codes and dead pedal. New VP44 from MWFI fixed it. SNOKING

 

[jcoop]

Not the test I wanted to do today, but took it on a short (20) min run and it was fine. Had check engine light on, checked the codes P1693, P1690, P1691, and P370. Not sure if they where current or ones from yesterday. I understand it will reset the codes after 40 starts or something like that.

Guess I will start searching for a pump. Like the 24mo warranty from Bluechip, but that pump is twice as much as one from others. Just want to be sure I get one with a new computer.

John

 

[mfurrh55]

Had a 2001 that did the same thing, it was the electronics on the pump, and you can't replace them,mechanic says to pour a bottle of water on the pump to cool it down enough to start it up and drive it to destination, so i bought a rebuilt pump from Graham international for 1100.00 and mine as core,Got rid of problem , then sold truck , Monte