Last night I hooked the scanner to the truck to retrieve some codes and determine why it wasn't charging. Dad's taking the alternator up to get it tested and replaced if its bad.

While I was there I did a cylinder cutout test (engine idles a little rough and has a noise in it at rpm with fuel), to make the long story short, #1 cylinder is not firing like the others are, the change is just barely noticable. And when I come out of that menu and back to choose a different cylinder the engine returns to idle and its still missing for a little bit. It will snap out of it if I burp the throttle a little, but will still idle rough.

I just put a set of F1 Mach 1.6's in it, so I don't suspect injectors as I had the same symtoms before with the old sticks.

Is this a sign that the VP44 is going to raid my back account soon?

 

reinstall the connecting tube on that injector, it might just be off enough to bypass the pop pressure of that injector. if that solves your problem call Don and tell him about it, if I remember right there was a guy that burned a piston down after a similar situation....he apparently scraped some metal into the injector via the con tube......I might not be remembering right so ask don for sure. he is your best source of info.

 

I remember that post, I'll check it out, but whats pointing me away from injectors is that this rough idle was present before I put these injectors in.

 

JD how many miles do you have? This sounds like a valve that may be burning out on you. My number 4 was doing something similiar when did the Cut Out Test. I had a bent valve & a busted valve head. Both were burned pretty well too. I hope this is not your fate. The injector tube is another possibility too, & a whole lot cheaper to fix. Good luck.

 

Right around 80,000 miles, I purchased it with 68,000. This noise (noise in the intake also, but I understand these things are loud to start with) and rough idle thing has developed over the last few months, at first it was hardly noticable, but lately it'll drive you nuts.

I did try reseating the connector tube, same behavior. I'm going to pull #1 and do a leak down, and switch it with a different cylinder and see what I find. I don't care what I have to do, I just want to find the problem and fix it.

 

while you are in there check the valve clearance

 

I figure I'd bump this and give alittle update. I switched #1 injector with #3 injector, still lazy on #1. I'm not suspecting injectors now.

I'm going to run it past the cummins shop today and see what they think.

 

Mike, have you run the engine with the valve cover off, watch for weak valve spring, or lazy valve? Did you have a drop in rpms as a result of a burned valve too? I'll PM you later, I might be in your neck of the woods 6 MAY06, I'll give you a call as it gets closer.

 

We had one with a miss that would come and go. It sounds a lot like what you are going through. We replaced all the injectors and the problem was still there. It was hard to pinpoint which cylinder was acting up. On ours i believe it seemed to be number 5 that was the weakest on the drop test. We ended up as a last resort replacing the vp-44 which cured the problem. When we asked chryslers star center along with or local cummins shop they all said the vp-44 was not going to be the problem. Customer was bent out of shape so to resolve it we tossed a pump on it and end of problem.

 

Pretty spendy part to throw at a prob huh Nitrousn!! been there done that!!

 

There is something else that I noticed, when your coasting in gear, I can hear something, maybe even feel it if your observant enough, very hard to describe it, but its there and gets louder with fuel and you can feel it alot more in the pedals.

Could it be the VP44, certainly, I haven't ruled it out yet, but I suspect a valve problem or maybe even piston problem in this case (although it doesn't huff and oil anaylisis shows nothing)

 

Hi Jay. You know how it is when under warranty trying to get help and get parts that are on restriction. Its one of those cases where the problem is uncommon and a one of a kind type deal. Every one says no way will the pump cause that when infact it is the pump with a glitch.

 

Boy it was a bumpy ride home in the jump seat on the 93.

Here's a little update.
The VP44 gave up the ghost tonight.
Now I need a VP44 ASAP (I need this one running before my trans goodies arrive), should I go Hot Rod VP or Standar VP?

We'll see if this solves the missing problem.

 

BTTT,
A little update for those who remember.
Tore into it last night, #1 cylinder wasn't firing right. Same behavior as previously described. Pulled the rocker arms, checked the pushrods, pulled the injector and checked the bore. Everything there looks good or great.

Pressurize the cylinder and had my helper listen in the exhaust. Hmm, not good, leaky (probably burnt) exhaust valves at a pretty good rate too. That and I'm not to impressed with the amount of movement I see back and forth in the valve stems.

 

...just curious. When the truck was running you mentioned a noise in the intake. Would that have been like a "woof, woof, woof" sound while running (hard to explain!) in the air inlet system? If so you'll most likely be pulling the head. Also not sure why but every 80K plus truck I've run into (maybe only three) the valve guides slop was pretty bad.