JD730

The truck in my sig, 2000 24valve of course, six speed, HRVP, Smarty is on #5, Mach 1.6's, Rebuilt head, o-ringed, studs, .020 marine gasket.

It basically sounds terrible and I can't find the reason. One mechanic friend of mine said it sounded like an air compressor and I think it sounds similar to a helicopter. I've tried it with stock injectors, stock ECM program, same noise, no change.
What I've found so far:
Pull the intake hose off the intake horn and pull the front 2 bolt out of the intake plate and you can feel air being pulsed out of the intake near cylinders #1 and 2, I don't feel this toward the rear cylinders. Not to mention the intake is LOUD, like really loud, hear it when I'm coasting, under acceleration, pretty much all the time. I can also feel it in the floor and pedals, especially the clutch when I rev up to downshift. It can be felt coasting or under power. I'm thinking cam, but I'm not going to through that if I'm not completely sure about it

Under light acceleration at highway speeds it surges, whole truck will start to jump around. Also pulling away from a stop it sounds and feels like it might be missing, see last paragraph. I've found that at idle this HRVP sometimes likes to miss and its not firing #1 cylinder, there will be not fuel coming out of the line when its cracked open.

It also will not cold start right without cycling the intake heaters, it will start, but it will miss on a couple of cylinders, it must be drowning them with fuel because the smoke is ridiculous.

So far no oil sample has shown anything wrong, only that pour good oil into the drain oil drum. Going to take another one this morning and send it out.
All the above symtoms/problems have been getting worse and more noticeable.

I know this is a tough one and I don't expect alot of responses, but thanks for at least reading it.

Thanks
Mike

dieselfan

i would definitely stop driving it! you said you weren't getting any fuel out of #1, but you get fuel form #2-#6? i m guessing all the smoke is from the #1 not firing, just as the air you feel coming back is from it not firing. if it was firing it would be going out the exhaust manifold.
how long have you had you HRVP, could that be the cause?
i know i didnt help you and probably told you what you already knew. sorry i couldnt help, hope you get it figured out.

also have you done a compression test?

JD730

It only does this sometimes and I believe it is related to the HRVP, it will push fuel out of the line if someone revs it up.

As for a compression check I don't have the adapter to do it and I haven't had the time to make one up.

As for driving it, its been making this noise for the last 20,000 miles, everything I've done has not changed it. If it was going to pop, I think it would have done it already.

Truckman

What do you have your valves set at?

m.rehme

No fuel at #1 ??

Don M

Measure the cam lift on the cylinders suspected. A cheap dial indicator and magnetic base is good, or even some makeshift thingy you can use to make certain with some accuracy the cam has not worn down.

The fact that you have been 20K with this problem makes me think the cam is probably not the culprit. They usually go down hill fast once they begin to wear.

Check the valve lash. Too tight will increase overlap and could pump air back into the intake manifold.

Since you can somewhat test the cam, I suggested that first, but the VP44 is sounding like the culprit, IMO. Unfortunantly, you cant check it.

pind

I would almost suspect that you have a bent exhaust push tube on #1, cam is doing its job, but the valve cannot. I have run into this problem on engines right through the range offered by cummins. Not a super-common occurrence, but it can happen.

Most noticeable symptom is popping or barking back through the intake. Cylinder can be firing, but exhaust has nowhere to go.

As much as I dislike popping valve covers to check things, or popping valve covers in general, I would suggest this route, and see what is happening in there.

JD730

My notes are in the shop, but I measured that and didn't find much of a difference between #1 and #2 cylinder.

Right, it also should have shown up in an oil analysis.

They were .012 and .022, I set them at .009 and .019 2 weeks ago.