1998 Buick LeSabre

[inafogg]

i thought we already found the culprit 115 LB PSI.i'd find out what the reason
for this issue is first.just my opinion??

[JLKINSER1970]

Originally Posted by Jrs3800

Not a good answer at all...

An injector balance test should tell quite a bit... and I know the Injector balance test can easily be done on the 98...

I hadn't heard of an injector balance test before.
I never feel the miss. I was told if it had a miss then I would feel it but I don't know if that is so or not. When I was testing the injector with the node light, the car ran fine without that injector hooked up.
Any opinions? Since all of the other cylinders seem to be firing I assume that if the number one is the only one that isn't firing then it is possible I wouldn't feel the miss. I know it sucks gas.

[JLKINSER1970]

Originally Posted by inafogg

i thought we already found the culprit 115 LB PSI.i'd find out what the reason
for this issue is first.just my opinion??

I was told anything over 100 LB was fine. But compared to the others, that was a very low reading I thought. Could a bad valve make the LB low or just the piston rings

[inafogg]

yea thats right the difference in cylinders if you pull the spark plug wire i'd bet
that does'nt change the idle much either

[HotZ28]

This thread is getting long, and sometimes we need to go back & read all the post to remember what was said. I agree with inafogg, if you actually have only 115 psi on #1, you may have a ring, or valve seat problem. If #1 appears to be pumping oil, (an indication of blow-by, or valve seal leaks); but usually leaking valve seals will not affect compression unless the guides are worn out. Can you pull the plug on # 1 & post a pic? BTW, compression on all cylinders should be within 10% of each other!

[Jrs3800]

Originally Posted by inafogg

i thought we already found the culprit 115 LB PSI.i'd find out what the reason
for this issue is first.just my opinion??

Completely my fault for not noticing that...

Agreed... 115 Psi is a bad thing...

I think general rule of thumb is that it should be at least 70% of the highest reading cylinder, but even then we all know it will not run right like that...

I do agree, it would be good to see the Plug... When the compression test was done was any oil squirted into the low reading cylinder to see if this would help bring the compression up?

[inafogg]

When the compression test was done was any oil squirted into the low reading cylinder to see if this would help bring the compression up?
__________________
POST #1

[HotZ28]

Also, it sounds like the #1 and #2 lifters are chattering.

Several things come to mind that coincide with noisy valve mechanism. There could be a broken valve spring or a bent push rod, one or both of the the valves could be sticking or leaking, or the camshaft has excessive wear and is not opening the valve(s). Pull the valve cover and take a close look.