I have had issues with my camaro for years. It had been over heating. Radiator, water pump, Coolant temp sensor, engine temp sensor were replaced few years ago. This year I finally got the time to change the head gaskets, and yes took the heads in to get check, resurfaced and valve job. Still overheats, cooling fans dont turn on, fans to work with direct power to them, relays changed, fuses checked. I just check Air pump which apparently is not working, so ill have to replace that. I have access to shop key and a Snap on modis. I also noticed that at a idle the knock is at 3 and the spark advance is 14-16 degrees, and when i bring the idle to 1400 RPM the spark advance goes up to 40 degrees knock is 3 and knock retard is 0 degrees. I had replaced the crappy opti spark distrubuter and cap and rotor few years ago with one from the Auto parts store. So I am down to changing the ECU. Any comments or suggestions, and also Its a 94 (late 93 early 94) Z28 with 104xxx miles on it, how much of a differance will it make if i get a ECU from a suppesed Police intercepter caprice with the LT1?

 

You say your fans don't turn on, but you can wire them direct to go on. Does it overheat with the fans running? If they're not on, there's your overheating problem.
And, your air pump not running isn't going to overheat the engine. That's to keep exhaust emissions down by injecting air into the exhaust until the engine/cats heat up.

 

The only way i have been able to keep it cool enough is running both cooling fans with just water and additive called 40 below.

 

thermostat?

 

Thermo was replaced. What about ideas on the Spark advanecd being so high? ecm, or malfuncting knock sensor or opti spark, i know the part store ones are not the greated but i only have maybe a 1000 or 2000 on that one, wich was replaces few years ago, havent had this car on the road for over 2 yrs now. Its depressing, and my birthday is may 6 and i cant even drive the damn thing.