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Miss at all RPMs

TFaoro
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MnTom

MnTom

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Posted

id toss in a different pump, its the last thing to be changed...

For the cost I wouldn't want to do that. His last IP tested just fine so there is something else going on.

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TFaoro

TFaoro

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Great thoughts guys! Sorry I have been away. Let me answer a few things here....

We don't have any Bio around here so that is not an option, but I appreciate the suggestion.
There is not an extra copper in #6, as I made a "special" piece of wire to pull those out (Some of mine didn't stick to the injector when the injectors were pulled)
Mike... Not a bad idea there... Although this is the second set of washers from DAP and they are the same thickness as my first set of injectors from them. I don't think I have the stock ones to compare to either... Could that cause the slight miss though? I wouldn't think a couple millimeters would cause spray to go outside the bowl of the piston. 
Another injection pump is not an option. Too much money and I was told it tested out perfect.
Tom - The valves have been adjusted a couple of times through all of this. No irregularities found there.
Rancherman - I will be testing that as soon as I get the pump put back in. I'm hoping it shows up tomorrow!  :pray:
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MnTom

MnTom

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The reason I said to adjust your valves was to have you check for excessive wear, excessive adjustment, lack of valve movement, etc. If you notice one adjuster different than the others it will tell you where to concentrate your efforts.

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TFaoro

TFaoro

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Pushrods have been checked and all 12 are straight. The adjustment on all of the exhaust rockers are very close, and the adjustment on all of the intake rockers are very close. 

 

i know you have done a compression test. but i still think there is a cracked/broken ring.

If there was a broken ring I believe it would have shown up on compression or leakdown test. 10 psi difference does not point towards a ring. 

The pump didn't show up today  :ahhh: So tomorrow I should be able to test the fuel with a clear line. I'm hoping it's something as simple as air in the fuel!

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MnTom

MnTom

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Pushrods have been checked and all 12 are straight. The adjustment on all of the exhaust rockers are very close, and the adjustment on all of the intake rockers are very close. 

 

Well, you sure shot the crap out of my ideas........

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Dieselfuture

Dieselfuture

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When you say miss at all rpm that means even before it starts to boost so you can rule out turbo and boost leaks, and if engine checks out good the only thing left is really fuel. And if injectors is not the cause how good is the place that tested vp. Other than that maybe valves or valve seats or even head gasket. And maybe when you did tests it's cold and doesn't leak, and if it gets to higher temps is when it happens. Man I really want to know what it is now. It's bugging me.

Edited by Dieselfuture
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TFaoro

TFaoro

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Without rereading the last 10 or so pages, did you narrow this down to one cylinder?

No sir... Can not seem to narrow it down to a single cylinder

 

Well, you sure shot the crap out of my ideas........

They have all been good ideas! I'm about out myself....

 

When you say miss at all rpm that means even before it starts to boost so you can rule out turbo and boost leaks, and if engine checks out good the only thing left is really fuel. And if injectors is not the cause how good is the place that tested vp. Other than that maybe valves or valve seats or even head gasket. And maybe when you did tests it's cold and doesn't leak, and if it gets to higher temps is when it happens. Man I really want to know what it is now. It's bugging me.

Industrial Injection is the one who tested it on their Bosch test bench, so I think they did a good job. As for temperature it doesn't really matter how hot the EGTs are or the engine temp ... it has that slight miss either way. Hopefully a piece of clear line will tell me there is air in the line. 

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rancherman

rancherman

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I'm wondering if you can just monitor the overflow coming out of the vp with a clear hose..

2 questions.

where are you 'hearing' this miss? in cab, or at the rear of truck, by the tailpipe? You feeling a stumble too? Does this miss disappear when engine is under load? (you only hear it when engine is freewheeling?)

Then, what kinda shape is your exhaust system in? Turbo- through- tailpipe?

Yesterday, I fired up my ol Massey with a 540 perkins, and right where the 'y' brings both exhaust banks together, it's a little loose. Simple slip fit, just needs the clamp tightened.

Standing back 20 feet while I was closing a gate, I could hear a sporadic pop-miss, ever so slight.

I says to myself.. hmmm, I wonder if that dude is mixing air and getting a pop... or he has a little oil leakage on the turbine side, causing a little pop-miss..

There is a slight chance of a broken ring, that when 'static' it will seal up under pressure. And it's fooling you.

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TFaoro

TFaoro

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Great questions rancherman. It can be heard at the engine (Hood open or closed), which gives a knock and shakes the truck a bit. It can be heard at the exhaust as well. The exhaust is a Magnaflow 4 inch turbo back with a muffler. All of the connections in the exhaust system are tight and not leaking (Verified this morning). 

 

As for when it misses.... freewheeling is when it is most noticeable. Once under boost you can't hear anything over the turbo so if it is missing under boost I have no idea. I'll see if I can test a bit more today and give you an accurate description. I haven't driven it in close to a month.

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rancherman

rancherman

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I was afraid you'd say that! *exhaust system is good* And the fact you can feel the engine drop a cylinder.

Hey, I'm too lazy to go back and read. Did you use a leak down tester, or just a compression tester? Also, to the best you can remember, did this come on all at once?

have you noticed a increase in soot build up in the tail pipe? what is your oil consumption doing?

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