How hot is to hot for the ICM to run

[pedal2themetal]

HI,
Mines on the fire wall above the transmission sort of.. it was like 140* with a no contact thermo. rest of motor was like 185, to like 135.
trying to diagnose a miss at idle and at speed 40 mph. . Replaced intake gasket, new coil, cleaned rotor and cap inside, plugs look light tan to off white.

Thanks take care be safe
tim

 

[Jerry Hall]

Can you isolate it to one cylinder, or is it random?

 

[yella71]

what is an I M C ?

 

[pedal2themetal]

oops ICM

 

[kiwigtx]

oops ICM

Ignition Control Module ???

If so....not very hot at all. If it's really hot, you have a problem - either a bad ground, or a bad secondary circuit.

 

[Kern Dog]

I have seen these referred to as ECM, ECU, now ICM.....I don't recall what the factory service manual calls them. I'd have to check.
Regardless....
I was driving around my town today with temps of......

....and my car ran just fine. I did not shoot a thermal gun on it today but in the past, I have pointed it at a summer time engine warm reading of over 135 at the carburetor, 150 on the intake runners, 200 at the thermostat housing but never thought to point it at anything electrical. It is a good idea though....chase what makes sense to you. I have a standoff bracket for my ECU on the firewall....

That was with the "4 seconds flat" FBO box that I tried running. The standoff bracket allows some airflow around it to try to cut down temps a bit.

 

[kiwigtx]

I have seen an ECU that got so hot, all the gel inside oozed out into a gloopy mess on the firewall. Not my car BTW.

 

[pedal2themetal]

HI,
Thanks for all the reply's. I'm going to get a plug wire puller today so I can maybe isolate it. It smells rich, Sometime I smell raw fuel under the hood, I was thinking power valve (carb had just been rebuilt by a carburetor shop, couple of months) so it shouldn't be a problem, Haven't see any vapor in it. I have true duels and there is a definitely a strange pop out the drivers side over the passenger's side. I've set and re-set mixture screws running max at 13 to 14# vacuum. But since it has a surge or miss at speed 40mph and faster, I don't think that's a problem.
Maybe a new cap and rotor, all and wires are fairly recent. I did have to clean a big goober off the rotor...

Thanks to all, take care be safe
tim

 

[pedal2themetal]

HI,
I think I fixed it.... runs much better not really missing but still has a strange note on the driver side exhaust. Changed the cap and rotor I have 8mm wires on order (Summit ). Didn't see any problems but the rotor pin looked funky. and the rotor did have some flash marks around where the button touches the tab. See pic.

Thanks take care be safe
tim

 

[pedal2themetal]

HI
Took it for a drive and blew the cobwebs/carbon out of it and It runs 100% better. going to have to idle it down and readjust the mixture's now from adjusting it while it wasn't running right.. Must have been the cap and rotor all the time...

 

[1963JAM]

HI,
I think I fixed it.... runs much better not really missing but still has a strange note on the driver side exhaust. Changed the cap and rotor I have 8mm wires on order (Summit ). Didn't see any problems but the rotor pin looked funky. and the rotor did have some flash marks around where the button touches the tab. See pic.

Thanks take care be safe
tim

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View attachment 1496182

You have me thinking of the Same problem I am having now with the summer heat. My cap and rotor look the same. I would guess the high heat could be relaxing the pickup just enough to create a gap between the rotor and cap pin causing an arc and the carbon flash we are seeing on the rotor.
Just a guess but a simple fix.