Ok ya all I have a 85 z51 vette. everything was working fine until i replaced the heater core. Once i did that i pluged everything back in and started the car. When i went accelerate the car bogs down a bit but as soon as the engine starts to warm up at a temp as low as 100 deg it works PERFECT i only have this problem when the engine's cool. ive been trying to figure out whats wrong, but im not getting far. I know everything is pluged in correctly So i need some help
thanks Andy

It's a pretty safe bet that if your car was working good BEFORE you changed the heater core, then suddenly it is NOT working right after you get the car back together, that you did something during that project that caused the problem. A wire not connected, a hose off etc...you could have pulled a connector or wire loose a long ways from where you were working...just go over the entire under hood area looking for any connectors or hoses that might have been pulled loose. I'd bet plenty that all it is.

Your symptoms remind me of an ECT sensor, but it is nowhere near where you were working. You were near the MAF burn off module, an 1985 only, item. I don't know much about MAFs, but I am aware the module for an '85 is expensive. Good luck.

RACE ON!!!

I'd bet the burn-off module behind the passengerside of the dash isn't plugged in all the way.