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Discussion Starter · #21 · (Edited)
Could a faulty wax ksb cause it?

Who knows. Mine works.
I also blew the fuel return line out..... No help

Lift pump is/was new from install....


I'm down to changing the ip to a new one, just to try. Then if that does nothing.... Recheck compression, although I cant see how that would be bad....... Or try different injectors.
 

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can u narrow down what cylinder is missing??? should be able to do that by crackin injector lines while its running, one cylinder shouldn't change when cracked. If all 4 change then I'd say it's in the injection pump, prob not puttin out the pressure it should be to the injectors.
 

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I had a crack in a fuel line to the lift pump and It kept a little bit of air going into my fuel filter, so until rpm camp up it would suck air, run rough and require me to crack injectors over and over. I dont have an explanation for another problem i had, The return line was loose and it would drip after shut down, then it would sputter and miss on startup until it had a few revs. I retightened and no more probs. Dont know if that helps at all.
 

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I'm not even sure it is missing from the video. You absolutley CAN tell wich cylinder it is missing by loosending the injctor nuts one at a time while it is running. If it slows down on each one you don't have much of a problem.
Look for any wetness or leaks around the lines - that could cause a weak cylinder.

How is the blowby?

How do you know your injctors are good? Even if they were new, one could have goten a tiny piece of dirt in it when installed etc....
 

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Discussion Starter · #26 ·
I'm not even sure it is missing from the video. You absolutley CAN tell wich cylinder it is missing by loosending the injctor nuts one at a time while it is running. If it slows down on each one you don't have much of a problem.
Look for any wetness or leaks around the lines - that could cause a weak cylinder.

How is the blowby?

How do you know your injctors are good? Even if they were new, one could have goten a tiny piece of dirt in it when installed etc....
I have cracked all lines. All have the same effect. All of them.

I'm 100% positive I am significantly rougher at idle than the two 4bts I have seen in person run.

My power sucks, my mileage sucks.
 

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Discussion Starter · #28 ·
Might have something else going on but not a miss.

How's the blowby?

Did it used to run better?
I think it did run better. But I honestly cannot say for sure.

My blowby through the tube seems to be greater than my buddies... I suppose I need to do a blowby test instead of compression?
 

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Unless there is a major puff puff puff out of the blowby tube or the oil cap when you take it off I wouldn't worry about the blowby. Rev it why you look at the blowby.

Are your valves adjusted?

There is always a chance that someone put the pump gear in a tooth or two off. That would make it run poorly!

Does it start well?
 

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Try raising you idle speed a little too. That might make you problem go away. P pump engines will lope badly with too low an idle speed.

I'd put a pice of clear tubing in line after the lift pump and before the injction pump and look for air bubbles. Just the pulse of the lift pump might be enough to make it lope.

Any air in the fuel will make it run badly and loose milage etc.
 

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i assume this behavior is the same under load?
i realise you have a new lift pump...but you may want to hook up a fuel pressure guage,and see whats what.
have you altered timing in a significant way?...experiment with the timing.
when you had the injection pump tested...what did they do?
i believe there's an inlet filter screen on the ve itself...where the fuel inlet enters the pump.maybe check that?

sounds suspiciously like delivery valves...wish i could help more,but i havn't been into to many VE's.
 

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Discussion Starter · #32 ·
He checked the pump, said it was all good. He even ran it while I watched and explained it to me.

I have tried timing, with no appreciable results. The reason I don't suspect the lift pump is I cannot detect the miss at high speeds, due to noise...
 

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Can't remember if you said you adjusted the valves? That can put one heck of a miss on it if they're way off. Also good to inspect your rocker arms & valve springs closely, and make sure you don't have a bent or broken pushrod. Other than that, maybe a bad lifter?

My guess is your problem is located there, somewhere in the valve train.
 

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Can't remember if you said you adjusted the valves? That can put one heck of a miss on it if they're way off. Also good to inspect your rocker arms & valve springs closely, and make sure you don't have a bent or broken pushrod. Other than that, maybe a bad lifter?

My guess is your problem is located there, somewhere in the valve train.
What if a couple lobes on the cam are wiped off??? I didn't even think about cam and valvetrain, you could do a test with a dial indicator on the pushrods, turn the motor over and measure how far up each pushrod goes.
 

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Really hoping you find it, Lee, and I know you will!

Have a similar problem on my truck, the Townie 4BT, with consistent miss, no matter what. I can feel it at all rpms, but checked everything and so far nothing! I'm pretty sure mine is an injector problem, find out if I can ever afford a set of injectors hah!

Also real hard to tell what's in an engine after all these years. Could be one short pushrod, something weird with a lifter, bad rocker arm bushing, one screwy valve or seat, one broken or wek valve spring, who knows?!

Mine was one of two trucks [another guy here posted that he FOUND THE SAME THING!] that had a Lincoln penny slipped under the edge of #3 valve cover in order to cause gasket to leak! Couldn't be an accident, no way in hell. It got intentionally placed there for whatever reason. Still have the penny here hah!

Just never know sometimes, lots of strange folks out there walking around among us....you already knew that...
 

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My only thoughts are possibly a slightly bent push rod(s) possibly. The dial indicator will show the lobe lift. Did you check the rocker arms for wear and the push rods for straightness?
 

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Discussion Starter · #38 ·
Blowby test is well within spec.

So i know its not that.

I'm sick, and tired of checking the valves.

I need to machine a base to hold my dial indicator, and the last thing I'm going to do is check the pushrods.

After that, I'm swapping injector pumps. After that, I'm swapping injectors.

After that? I'm swapping motors.
 

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another thought that crossed my mind. Did you check the firing order to make 100% sure you have the lines on the pump going to the appropriate injector??
 
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