my heat sensor or somthings wrong help?

i went to put a zc in my car, things didnt work out. i put my stock motor back in, it runs good, when im driving my heat meter will fulxuate up and down. when i turn off my key and turn it back on it will read normal then start fluxuatiating again. someone help

Hi Noob! Welcome!

If you don't have a Muti-meter I'd try replacing the temperature gauge sending unit. It's cheap and easy to get at (it's the small sensor under the dizzy with a single yellow/green wire attatched).

If you have a meter the resistance cold should be around 142 ohms and should range between 49 and 32 ohms as the car warms up. GL

thanks worked, about to but a zc motor in my car, will it be fast or what.

Should be quick, the ZC has like 130hp. GL