runs fine when weather is hot

[87-911-coupe]

looking for advise.gotta 87 coupe 3.2 no mods. car runs rough from idle up to about 3500rpms feels like 1 or 2 cylinders not firing. seems to clear up beyond 3500-4000 rpms. odd thing is problem is not present when outside temperature is above approx 85 degrees car runs fine..my best guess is CHT sensor but thought I'd ask here before spending the money...thnx

[ZOA NOM]

Definitely do a search on rough running, mixture, plug wires, intermittent, etc. There are several things that can cause these cars to run rough. I've found the most temperature sensative item to be my mixture setting. Have it checked with a gas analyzer before replacing any parts.

[jbrinkley]

a truly bad CHT would not let the engine run at hot start. At least that's my experience.
did anyone just mess with the plugs/wires/cap/rotor?
what zoanas said though, mix first, check spark on all 6

[87-911-coupe]

i've repl'd plugs, rotor and cap to resolve but no help...plug wires are a couple of years old..havn't done valves since last year..guess i'll meter CHT just to make sure then find someone to analyze my exhaust..thnks for ideas

[jbrinkley]

just so you know, not trying to be a dick, the cht can test fine on a VM and still be bad

[stlrj]

..plug wires are a couple of years old..

To make sure they're still ok, spray some water on them at idle and see if it misses.

It's all about testing, not guessing.

Joe

[ZOA NOM]

You can also check the wires in the dark. Look for tiny sparks.