Misfire at idle and light throttle
 

Hey guys so I consistently have a misfire at idle (had to make idle super rich 11-12 just to keep it from dying) and also at light throttle. I changed out the plugs and it still does it. Wires are ngk blues with around ~10k miles. Should I change out the coils? Car has 78k miles.. Oh and my tach has been going crazy for forever. It drops out and back in inconsistently but I have been unsuccessful locating its ground. Any advice appreciated

Could it be an injector that's leaking fuel? When the pulse width goes short, one cylinder runs rich and the other ones lean. Increasing the load would even it to the point where the difference between cylinders is smaller. Did the sparks look roughly the same? Don't know about the tacho though..

Yea I guess anything is possible but I haven't noticed any leaks. Seems to spark good but I'll check all the wires with a timing light soon to make sure their sparking.

Any updates to this issue cowboys?

Did a compression test and cylinder 4 was really low so did a leakdown and 60% was leaking from that cylinder. Our guess was the rings because it sounded like it was leaking through the crankcase. Have all the parts for a built engine on the way.

That sucks. Oh well its a good opportunity to build a nice stout bottom end now at least.

Out with the old and in with the fun :) in some ways I envy you. I'm at 255,000 and counting.

Yeah I'm not sure if it's a blessing or a curse but luckily I had the money and since the engine is out I might as well go all out with my measly budget. :)

Hey guys, so after building my engine I still have this same miss. The only thing I didn't mess with was the head. I did a compression check last night and the compression is good and consistent. I'm going to try and borrow my brother's cam and crank sensors and see if those make a difference. Any other ideas?