Engine/Transmission (1998.5 - 2002) loosing prime

[AllianceDiesel]

Hey on my 02 cummins 6speed, when I let it set for like an hour, I go to start it and it will start fine but it blows out a big puff of white smoke and the engine sounds like when you are bleeding the injectors (that real loud dieseling sound) I got a raptor 150 feeding 18psi to the injection pump last time I checked. No codes. Im thinking that its somehow bleeding the fuel back. I really can''t think strait right now because I really can't be having my truck running like **** right now. After you run it for a while it runs fine and starts fine. Ive pulled the fuel filter out and check it and the oring, they are fine but Im gonna change them anyways tomorrow since its cheap. I have change the banjo bolt on the vp44 supply line with a normal one and new washer seals (the old one had the schrader valve wanted to eliminate that just incase). The only thing I can think of right now is either connector tube orings or injector orings. There are no fuel leaks, Im thinking that somewhere air is getting in, I will hook up a gauge tomorrow and see what happens when I start it and it acts up. No codes, reman injeciton pump at 85000 truck has 93000 on it.



Any thoughts would help,



thanks

mopar

 

[blacksheepdiesel]

Do a search, some guys found that parking uphill or downhill would affect whether or not their truck acted up.

Godspeed,
Trent

 

[AllianceDiesel]

I know uphill does it because thats when I first noticed it was when I parked in my parents driveway during the holidays

 

[JLandry]

I know uphill does it because thats when I first noticed it was when I parked in my parents driveway during the holidays

Does it exhibit the problem every time you start it after sitting hour whether parked level or not?



I agree with you that it sounds like a lean fueling issue.



One thing you could try is to temporarily install a length of clear tubing between the fuel filter and VP44 to watch for air bubbles when restarting after sitting for an hour.



How many miles are on the VP44?



John L.

 

[EBung]

I just had this problem after an injector swap. The one thing I did different was a guy said to alternate tightening the injector hold down and the injector line. This causes the copper washer to not seal in the head because it coks the injector in the head. So I did the whole thing over again with new copper washers, tube and injector o-rings and tightened the injector hold downs to 96in/lbs then installed the lines on the injectors and now it starts like it is supposed to. I still have slight fuel leakage at the line at the head and may need new lines but it runs fine. I would make sure your hold downs are tight.

 

[Huff N Puff]

The usual culprits are:

The fuel modules, fuel line quick coupler,or the coupler from the steel line to plastic under the drivers seat. Did you check the check valve on the VP44's return line.

 

[AllianceDiesel]

Alright, tested the return line pop-off and its working fine, checked the return fitting on back of head its good. Parked the truck this morning with the nose downhill started it like I usually do, blew out a huge cloud of grey/black smoke and shook real bad, when driving the truck it will blow out a trail of white smoke, so Im starting to think I got a bad injector. Got injector o-rings and connector tube o-rings comming, have two sets of stock injectors in my garage so gonna do a quick swap, if that doesn't fix it, gonna swap out the injection pump.

 

[JKinney]

I gotta throw this question out there: Is there enough fuel in the tank? The guage could be lieing...

 

[AllianceDiesel]

brand new fuel module, and only have about 100 miles on the tank, module was replaced with the old style so I could put the raptor on the truck without using the draw straw, truck runs fine after you drive it for about a mile, smoke goes away

 

[GaryOwen]

How about the grid heater?

 

[AllianceDiesel]

works, it does it even when its 50 degrees out so its has nothing to do with heat

 

[JoeCanuck]

I had an injector tube with a very slight leak that was causing startup problems. The only evidence was the number two injector tube was slightly wet and there was occasionally a light diesel smell.

I tightened up the tube and all is well.

The really strange thing is that the starting issues happened without me doing anything to the engine. One day it started fine; the next, lots of cranking.

Still, I don't question the results. Good luck.

 

[JKinney]

Are the connectors above the tank on the install leaking air?

 

[AllianceDiesel]

Im gonna pull the box one of these days so I can get a good look at the connections on top of the tank, also gonna pull the supply line to the vp and hook a clear tube up to see if im getting air in the supply so I can eliminate that.



Swapped injection pumps today, gonna let it sit and see what happens.

 

[grimesja]

A leaking fuel line at the injector will definitely cause that problem. Do you have fuel dripping off your transmission bellhousing? The leaking fuel line will cause cavation. A quick check would be to let your lift run before starting the truck.

 

[AllianceDiesel]

No fuel leaks anywhere, I actually wish I had a fuel leak it would be easier to find the problem, as you can tell from my name this isn't my first rodeo, but the only thing we ever saw go wrong on the vp trucks was the vp/lift pumps and connector tube orings which would cause a hard start/long crank times cold, but start fine normally.



swapped out injection pumps, still acts up, might do an injector swap tomorrow real quick and see what that does, had my buddies smarty on there today on level 9 and was getting a miss at idle, so maybe signs of a bad injector. HOPEFULLY, just kinda throwing parts at it until that check valve comes.



Tell me if im off my rocker, but what happens if an injector is sticking causing the fuel to leak into the cylinder when it shut off, this would cause a loss in vacuum letting the fuel leak back, the reason I say this is because you let it sit not even 5 mins. and it starts hard and the smoke is pure diesel (not the good black diesel, I would take that color of smoke anyday). Once you drive it about a mile the white smoke is gone. I don't know, maybe im just thinking way too hard, should go back to the K. I. S. S method, Keep It Simple Stupid.

 

[Ram4Sam]

No fuel leaks anywhere, I actually wish I had a fuel leak it would be easier to find the problem, as you can tell from my name this isn't my first rodeo, but the only thing we ever saw go wrong on the vp trucks was the vp/lift pumps and connector tube orings which would cause a hard start/long crank times cold, but start fine normally.



swapped out injection pumps, still acts up, might do an injector swap tomorrow real quick and see what that does, had my buddies smarty on there today on level 9 and was getting a miss at idle, so maybe signs of a bad injector. HOPEFULLY, just kinda throwing parts at it until that check valve comes.



Tell me if im off my rocker, but what happens if an injector is sticking causing the fuel to leak into the cylinder when it shut off, this would cause a loss in vacuum letting the fuel leak back, the reason I say this is because you let it sit not even 5 mins. and it starts hard and the smoke is pure diesel (not the good black diesel, I would take that color of smoke anyday). Once you drive it about a mile the white smoke is gone. I don't know, maybe im just thinking way too hard, should go back to the K. I. S. S method, Keep It Simple Stupid.

Since white smoke is a sign of low combustion temps, and you suspect a bad injector, try this. Get one of those infrared temp guns, have a buddy start the truck and run a high idle rpm, while it is smoking, check the temp of the exhaust manifold at each exhaust port and see if one is running colder than the others.



Sam

 

[rivercat]

awsome thread I have the same problem after having the head off twice I have regular start up only with white smoke then a bad stumble at anything more than idle while the vp re primes have changed the oring on the return back of head, changed the crossover tube orings. Multiple key bump lift cycles have taken the stumble out some times but the white smoke is always there on anykind of cold or even warm start (sitting more than 20 mins). By the way I run the stock style carter and a 7# on the frame. changing the copper washers sounds like a good fix unless my vp is giving up noticed it don't spool my sps like it used to and seems like it runs quieter (less timing)

 

[AllianceDiesel]

ok so I thought the injection pump didn't fix it, went out the next day and it started just fine all day, its been two days and not a single problem, I currently have a s. o. pump on my h. o. motor which I thought you could do but I guess you need a s. o. computer, so I had a h. o. pump from when I worked at the dealership and its on my buddies s. o. truck right now, so Im gonna give him back his s. o. pump and get the h. o. pump back onto my truck because I like the way it feels when you boost and it puts you in the seat. Been running the smarty on it just so I have power, completly stock its gutless.



Hope that helps

 

[HCannon]

I have the same problem, found that if I dont tighten the cap down on the tank everything is OK.