Only running on 3 of 6 cyl

Just went out and reran all spark, fuel and compression tests. Pictures are always better.....

*EDIT- x means the tester shows I have it*

Camaro.jpg
 
1BADAIR said:
check the rockers on #3
maybe back them off 1/4 turn
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Seriously? A 1/4 can fuck with you that much? How does that explain the other two cylinders though? Spec for the rockers is 3/4-1 1/2 past removing the play. I did 1 turn on all 12 of them.
 
depends on how good the preload spring in the piddle valve in the lifter is at retainging oil. I would back both rockers off a bunch.

As for the other 2 cylinder missfiring. It could be air disturbance if the intake valve is hanging open. Basically it could be egring itself to death.

GrandmaLS said:
Seriously? A 1/4 can fuck with you that much? How does that explain the other two cylinders though? Spec for the rockers is 3/4-1 1/2 past removing the play. I did 1 turn on all 12 of them.
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Sean said:
depends on how good the preload spring in the piddle valve in the lifter is at retainging oil. I would back both rockers off a bunch.

As for the other 2 cylinder missfiring. It could be air disturbance if the intake valve is hanging open. Basically it could be egring itself to death.
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You saying to back 5/6 off a bit too?
 
Damn, still working on this thing? Sorry I ain't around to help, cuz I remember a similar problem last time we did an upper end job on that engine.

Yes, a 1/4 turn too much can make it so the valve never gets a good seal. I've had lots of fun on these chinese motorcycle engines with adjusting valve lash.

Good luck!
 
CLC85TA said:
Damn, still working on this thing? Sorry I ain't around to help, cuz I remember a similar problem last time we did an upper end job on that engine.

Yes, a 1/4 turn too much can make it so the valve never gets a good seal. I've had lots of fun on these chinese motorcycle engines with adjusting valve lash.

Good luck!
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Our problem last time was we didn't have a spec so we only did like 1/2 turn and they were ticking. Too tight, too loose, next time they'll be just right..... God, I hope there is no next time. I don't care if the PCV is plugged, next time this car breaks down its staying broken down until an engine worth having is ready to go in.
 
I know this sounds dumn, but if its running with no comression after you did head gaskets are you sure the gaskets sealed properly??........was all the old gasket materal and crap cleaned off the deck??
 
turbo89gt said:
I know this sounds dumn, but if its running with no comression after you did head gaskets are you sure the gaskets sealed properly??........was all the old gasket materal and crap cleaned off the deck??
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100% of it. I spent 2 hours cleaning the head surface on the block and the heads.
 
dave89iroc said:
why did you do head gaskets?

did you have the heads gone through?
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Did the head gaskets because I THOUGHT they were leaking. With the alternator bracket in place you can't see very clearly but I was 99% sure it was the headgaskets. Did them, put it back together, and still leaking. It was the timing cover gasket. Pulled it, replaced it, and no leaks. The heads were gone through.
 
Try starting the motor up and backing off the intake and exhuast rocker a half turn at a time. See if the cylinder pick up. I have had some iffy lifter in the past that required me to lash them running. Given th emileage of the engine the lifters could just feel really light for judging preload. I would start with cylinder #3 and see what happens.
 
Maybe it simply just has a dead hole, and your chasin your tale.....if the reason you changed the head gaskets was for no compression and it still has no compression.......hmmm i hope not though!!
 
If I remember right from last time I helped him, you can't adjust the lifters without pulling the intake.

don't worry, Tom, I'm keeping an eye out for LS-based engines for that thing.
 
put the push rods in backwards? Are they the same length or the different lengths like the newer 3100 and 3400's?
 
I loosened up both valves on #3 to no change in compression at all. I was reading through the manual again and remembered something. The felpro gaskets were not labled "Top" or "This side up" The holes were identical both ways but depending on what side you were looking at, there were metal rings showing or not. In this manual it doesn't show a picture for one way or the other. Does it matter what way those rings face? I think I put them facing down. Once again, the holes are identical either way and the gasket didn't say it mattered what way went up.
 
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