Rough Running when Cold

[isby]

A new condition has just reared its ugly head in my ‘84 3.2. When cold, it starts fine but when accelerating it almost feels like one of the cylinders is missing. It’s especially noticeable at low RPMs. However, once it’s warm, the problem goes away. Could it be a failing CHT sensor? I replaced this sensor about 4 years ago. Thanks in advance for any input/ideas.

[917_Langheck]

Are you running the O2 sensor? How many miles on it?

When was the last time you cleaned the throttle body and the air flow meter?

All your air management lines connected and not cracked?

Check the ignition cap for buildup on the trigger points on the inside, and arcing to the plug wire where they contact the cap; also loose boot to the plug (none of these are a likely fault, but could be part of a cascade of failure points).

And, as always, clean and secure those ground points.

[Schulisco]

+1 on the oxygen sensor.
But if its really only one cylinder, this should be measurable with a IR temp gun on the exhaust for differing temperatures.

Also:
Check the injectors and their spray pattern.
Check the spark plug cables for breaks.

Thomas

[wazzz]

Could be so many things.
But since you have an '84 and its particular spark plug wire routing for RH bank, it may also be worth checking that your car was later on equipped with the fix introduced by a Service Bulletin in order to keep the spark plug wires for cyl. 5 and 6 away from corresponding injectors. Without this fix, spark plug wires can interfere with injector signal.
More info in this recent post here.