Misfire only when engine compartment is hot

HarryHaller

New Member
My '94 Integra LS engine started misfiring two weeks ago on the way to a job. I turned around to get her home, and the misfiring stopped after about 10 minutes.

I replaced the fuel filter and spark plugs, and checked the ignition wires. One of the latter was loose at the distributor cap, and I pushed it tight. Ran great for nearly two weeks...

But then I got the same misfire (seems to be just one cylinder) the other day. In both cases, it happened when the car was headed directly towards the summer sun, and had just been moving slowly or stopped. The second time, the problem went away within a minute or so of having the car in motion. The temperature gauge showed that the engine was in the normal range.

Conclusion: The problem occurs when the engine compartment is overheated. Check Engine light doesn't come on, nor does any other dashboard warning light.

What component, not directly in contact with the engine, could be failing at high temperature and not trigger a fault indicator, and would cause misfiring of one cylinder?

anybody?
 

Muckman

Not a M0derator
Ignition coil is heat related when failing.
If its one cylinder it could be spark plug or spark plug wire - probably time to replace them anyways.
Other things to look at are distributor cap and rotor.
 

HarryHaller

New Member
Good ideas--thanks. Yes, 180k maintenance says to inspect wires and distributor cap and rotor. Any would be consistent with symptoms, and no harm in replacing regardless.
 
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