1991 Tercel - miss #4 cylinder

[Boss 302]

Just changed the clutch, pressure plate, and throwout bearing in my daughter's 91 Tercel. Engine was running great prior to removing it.

Put it back together and it misses at a low speed, clears up as revs increase but uses a ton of gas. Problem is with #4 cylinder.

Started by checking for any loose wires, missed wires because the engine was out. Everything is hooked up as far as I can see.

Checked the plug and compression. Car had new headgasket a few months ago, compression was fine and spark was good.

Figured the injector may be dirty, removed it and it was carboned on the bottom. Cleaned it and switched positions with #2 injector, which was working perfectly. Miss is still there and stays with the cylinder, not the injector.

Hooked up my circuit checker and electronic pulses to the injector seem to be fine. Pulses on the right terminal, constant on on left terminal.

Thought the injector relay may be misfiring, changed it Saturday but same problem.

At present, injector is unhooked so car misses all the time (naturally). If we hook it up, it dumps fuel in the cylinder.

Any suggestions, I'm stumped with this one.

Thanks,

Boss 302

[97cavalier]

Um i can only think of a copple things. Check the intake valve and valve spring. while you are there check the rocker arm and the cam might be worn out in that spot and not hitting the valve all the way. I would start with the valve though.

[uti-student]

Sounds like something with the ignition system. Is the ignition system waste spark/ coil over plug. A possibility check ur coil resistance(secondary coil) match to specs if read OFL replace. Also check your spark plug wires for resistence could be low that is why it is miss firing not enough hot spark. good luck with ur problem. hope ya get it fixed