Code 43 and running hot

[LeftVentricle]

1989 Celebrity, 3.1 MFI. I have a code 43 and I'm not sure what it means. According to the internet:

Code 43: Electronic Spark Control Unit
The ESC retard signal has been on for too long or the system has failed a functional check.

It doesn't occur when the car is cold. Once operating temperature is reached the light comes on and idle speed and performance drops. Will also run hot if stuck in traffic. I know the cooling fan works, because I have it wired to be on with ignition, so the high temperature boggles me. (The reason for the direct cooling fan wiring is because it stopped coming on altogether some time ago, even with a new relay and motor.)

Suggestions I've received range from using higher octane fuel to replacing the MEMCAL to replacing the EGR valve and thermostat. Any validity to those?

[LeftVentricle]

Nobody wants to help me out here, eh?

[1988GTU]

Replace/Inspect the knock sensor circuit. Your engine is pulling timing causing it to work hard and most likely causing higher ct's. Also if your trans is slipping, that too will contribute to higher engine temps.

[LeftVentricle]

Dammit, I bought a knock sensor a while back, fully intending to install it, then promptly forgot. Bonehead.

[Superdave]

Lol yep, that's probably it.

[LeftVentricle]

No, I didn't forget to install it. I returned it for food money. Bought a new one. Will install tomorrow so I don't burn myself.

[1988GTU]

I might be able to snag you a junk yard one .... wont cast you 40 + dollars. lol

[LeftVentricle]

Thanks for the offer, I already bought and installed a new one. Car runs fine now. Thanks guys, wish I had done this long ago. The one I pulled out definitely looked like it was original, so I'm impressed it lasted as long as it did.

[LeftVentricle]

Still running hot when idling for protracted periods, but will cool off and stay cool while cruising.

[1988GTU]

How new is your rad? How old is your T-stat? Still getting that code?

[LeftVentricle]

Code is gone since I put in the knock sensor. Radiator was replaced last year. Thermostat was replaced last month with a 180* unit. Cooling fan is hard-wired to be on any time the key is in the ON position.

EDIT: I spoke to my mechanic briefly today about this, seeing if he thought it might be the water pump. He said that the only way the water pump would be bad with the symptoms I described is if the impeller fins are worn down to nubs, which is, in his opinion, quite rare.

[1988GTU]

Is the fan wired correctly?

[LeftVentricle]

Is the fan wired correctly?

Not sure what you mean by this. The fan comes on with the ignition and stays on until I shut the engine off.

[1988GTU]

Is the polarity correct?

[LeftVentricle]

It blows in the right direction, if that's what you're getting at. Otherwise, I don't know, I didn't wire it, my mechanic did. Also, if I run the air conditioning, it will cool off in a hurry.