Engine/Transmission (1998.5 - 2002) 100HP injectors installed, now it stumbles

[jmarx82]

This is not the truck in the sign. This is my friend's truck I have been working on. It is a 02 with 95k on it. We put a set of 100HP inj. in it and now it has a very noticable stubble on acceleration and white smoke. The problem seems to get clear up once the truck is warmed up, but you can still feel it. He is running a 95gph fass and quadzilla tuning. The fuel psi is a steady 16psi. The problem doesn't change with or without the programmer hooked up, not hooked up, etc. There are no codes or check engine light. The VP44 was replaced 7/06, at 60k, under warrenty. I am thinking that the VP44 was going out and now with these injectors, it just made the problem more noticable. I was wodering is anyone had anymore input before I throw a $1000 part on. Thanks

 

[Sticks]

Double check to make sure all the lines are tight. At 100k, the O-rings on the cross over tubes may be bad, or are not seating right in the new injectors.

Try cracking open the lines one at a time to isolate which cylinder has the stumble.

 

[jmarx82]

I replaced all the orings on the crossover tubes. I did try cracking lines one at a time, and had no luck isolating one cylinder. I even tried it with someone in the cab, with the truck in drive, to put a little load on the engine. The truck idles normal. Its just under acceleration and crusing while cold. Once its fully warmed up, you can not feel it at cruising, just under acceleration.



Here is another reason I think its the pump. Yesterday, after running the overhead, I started it, idle was normal. I revved it up to 2k or so, it stummbled and white smoked, came back down to idle. It had a hard miss for approx. 10 seconds, and cleared up. Almost like the timing in the pump decided to catch up.

 

[Sticks]

Starting to sound like a VP, but there may still be other possibilities.

Crank sensor, tone wheel, TPS...

Try a rev test when the engine is at operating temps.

Truck in neutral, from idle, mash the throttle and hold at wide open for a few seconds. RPMs should increase smoothly. Smoke should be a little puff of black/gray then nothing.

If the truck starts coughing and blowing white, then I'd just about confirm VP (except that this all started with injector replacement).

What brand of injectors, where did you get them?

BTW, whats the air filter like?

Checked all your ground connections?

 

[jmarx82]

Yeah, it just keeps doing the same thing. I bought the injectors from FTE Diesel. I have bought injectors and injection pumps from him before and never had a problem. I really think the VP was failing and the new injectors set it over the edge. And I also found out today that he had been running his Quadzilla levels 7-10 the past two weeks.



I don't think its the injectors because it seems to idle normal, and the problem seems to come and go. I also really can't narrow it down to one cylinder.



Airfilter is clean, and grounds are good.

 

[WDixon27]

spitting and popping with white smoke on a diesel is usually not enough heat to burn the fuel, via timing, injection pressure or other means

 

[Sticks]

Quadzilla...

OK. Remove/disconnect all programmers, chips, boxes and the like (not just turn off). Get the truck back to near as stock as possible. Lets eliminate the possibilities that something else is messing with the timing and fuel levels. I am not familiar with the Quadzilla box. Does it tap into the VP pump wire or use a pump PC cover/lid?

Rinse and repeat.

 

[jmarx82]

Yes it does tap the pump wire. Yes I did completely unplug everything and take it completly out of the picture.

 

[THoltz]

Not a hijack attempt, but what causes the white smoke?

 

[BGlidewell]

Not a hijack attempt, but what causes the white smoke?

see post six

 

[Sticks]

All this and still no codes?

 

[Vaughn MacKenzie]

Before assuming it's a dying VP44 try putting the stock injectors or known good injectors in there to see if it clears up.

 

[SSolderitch]

adjust the valves? I had a friend do a head gasket/injectors and didn't get them right the first time... .

 

[Tractorat]

Just goes to show you that if you drive your truck into a competent diesel shop and give them some money, everything starts to work again. Its just like magic.

 

[waltk]

The new injectors might advance your timing too much. I had much the same problem at start up in my 99 with 370 marines and smarty with advanced timing set come winter in new york. With even bigger injectors, you might have the problem in warmer weather.

You seem to have perfect pressure for the pump, not low enough to kill it, and not high enough to blow seals.

Also, no accelerator response is more of a VP death sign in my experience. And the truck obviously accelerates.

 

[Missouri Mule]

Blue Chip Diesel has good info on how to check out the vp44.

Blue Chip Diesel Performance Specialists



Putting stock injectors back in sounds like a good idea.