1981 chevy malibu question about spark plugs and running rich

yea, and it was all dry tested no wet test.

these are the plugs in order like they were in the engine on the right sid it goes 1,3,5,7 and left side 2,4,6,8. the ones that are pulled back were wet the others were dry and look the same as the pix

The 150’s might be OK, considering the radical cam.
#1 and #7 have serious problems.
Gotta open 'er up.

should i do a a leak down test. or not.

I’d test 1 and 7 this way - put #1 on bottom dead center, pressure up the cylinder a bit with air, and listen for where the air’s leaking - intake, exhaust, or oil filler cap. Then repeat for #7. Make SURE each is at bottom dead center first.

ok i will thanks, i also did wet test to #1 and #7 no change ill tryleak down test next and post results thanks

I almost forgot, it needs to be with both intake and exhaust closed - wonder if you cam does that? I’ll let folks who know more than me suggest a better way. Perhaps at TDC on compression stroke, with engine firmly locked in place?

And also listen at the radiator in case of a blown head gasket.

what amount of psi do i use also

Most leakdown testers just hook up to shop air and use whatever you are using to run your air tools, so 90-120 psi will be fine. This, of course, means you need compressed air to do this test. Hope you have an air compressor in your garage.

I don’t think you need to do a leakdown test to figure this one out. The problems you have with this engine should not even require that much effort to clear the waters up.

Squirt a little oil in Number One and retest. Pick one of the other 150ish cylinders and do the same. If the readings go up by 20, 30, 40 PSI, etc. then the rings are fried.
I wouldn’t go overthinking this problem because if those 2 show a ring problem the entire engine is toast anyway.

i did wet test number 1 and 7 there was no change

and yeah i do have a air compressor

It might be a good idea to pull your valve covers and check for damage to rocker arms, push rods, and valve springs. Especially for that #7 with no reading. Damaged valvetrain components can certainly limit compression readings and definitely could cause a total lack of compression. Does this engine run poorly and seem to have a dead miss?

With no change during a wet test this points to a cylinder head valve problem.

However, you should run a wet test on at least a couple of those cylinders with 150 PSI or so compression to determine if they have a ring problem. If they do then any cylinder head issues are irrelevant.

Another possibility on the 1 and especially the 7 is potential piston damage; say due to excessively advanced ignition timing. This will chew up the edges of the pistons (and rings) and the problem may be severe enough that a wet test will not seal it good enough to produce a higher reading.

ok when i did the home made leak test, i heard air coming from the valve cover openings for the pcv valve and the other 2 openings on the aftermarket valve covers. also threw the oil dip stick. i for got to listen at the exhaust though should i retest…
this was for the #1 spark plug hole it didnt leak anywere else besides that

and for the #7 hole air was rushing threw the exhaust could here it very loudly and fill it it wasnt leaking any were else

what does this mean

maybe rings in number one and exhaust valve in number 7?

and thanks to help so far

Somehow, I think it’s time to write this off as an educational expense and move on…

Step up to a factory assembled, fuel injected automobile and get back to enjoying life…

probably not, my wife has a fuel injected car and i had to tear the engine halfway apart just to change a broken timing belt if it was an interference motor i would b in the same boat. i would pick an old school over somethin new any day thats just me though

any more help out there

If you had air coming out of crankcase openings from #1 (PCV, dipstick tube), then either your rings are completely shot or you have a hole in the piston. As for #7, air through the exhaust indicates either damage to the exhaust valve or seat, or the test was done wrong (with the exhaust valve open). The total lack of compression on that cylinder would seem to indicate valve/seat damage. Ether way, the heads need to come off to further assess the damage. Even though the damage is confined to one bank, you may still end up redoing the whole engine.

i cranked the engine untill i felt little air on number 7 then i used a screw driver to tell when the piston stopped at the top,

for number one i manually cranked it tell i heard the puff of air then used the screw driver to tell when the piston stopped, is this right