dludden

My 1985 GSL-SE RX7 skips and stutters and fades out after starting when engine cold and also driving after but then suddenly it usually smooths out and runs fine after a few minutes. it sounds like a plug misfiring or clogged fuel filter but if it smooths out later then it's something else? My first mechanic has no clue but another mechanic said from my description it sounded like a stuck injector or PVM. Any thoughts as to the problem? Thank you!

LongDuck

Check your connections to the coils on the driver's side firewall and make sure everything's clean connected and tight. Any kind of miss during cold start could mean a plug that's fouled, but you can pull those easily enough and check to see if they have a lot of carbon buildup. New plugs would rule that out pretty easily, too.

Also, check your distributor cap and rotor - during cold weather, these caps are known for cracking and once cracked they can cause random missing. Usually people notice this after getting a car out of winter storage, but worth looking into now.

The -SE has a cold start mechanism which sets a fast idle cam when you put the gas to the floor and then let up completely to crank it and start it. Once the engine gets up to temperature (specifically the throttle body and Thermowax Pellet) then the idle drops back to normal.

Stuttering is a generic term, so if you can describe that better, it might help with diagnosis. If the engine runs up and down - it's sticking throttle body plate rods and an easy fix by removing TB and lubing the rods liberally with spray lube. Get back to us, as I'm sure someone here has had a similar experience. Good luck,

dludden

Thanks for the info. I replaced plugs, cap, rotor & wires in June so I don't think it's any of those but I could check the coil wires to see if loose like you suggest. When I go down the highway it starts to lose power, fades out, for a second but then comes right back to normal. It sounds mostly like a clogged fuel filter to me with all the skipping that is erratic but sometimes sounds not erratic like a plug misfiring. So when I started it last week it took about 3 minutes for it to smooth out, I mean it went from lousy to all of a sudden it was normal and I drove it several miles with turning the engine off and on and no problems!