I recently painted a friends engine bay(90 crx), and the paint seems to be peeling off.

I've painted many engine bays, and this is the first one to give me this problem.

For example. I painted the mounts and when i screw in the screw paint starts coming off.

- I was tightening the shock and camber nuts on the shock tower, and after i tightened all four nuts, the paint peeled off.

I do the same for all paint jobs. Sand the paint off the engine bay. clean with water, and then dry, followed by a tack cloth. I then throw gray primer and let it dry. Sand the primer down, clean with water, dry, and then wipe with tack cloth. lay down base coat. 3 coats usually. let it sit for about an hour. then 3 coats of clear.

What am i doing wrong?

 

gotta use more than water to clean that surface, especially in an engine bay where there is alot of dirt/dust/oil
You should use a wax & grease remover, get something from a paint store...the point of it is to bring contaminants to the surface, then you wipe them off...
So, Wipe on wax and grease remover on a smallish area with a paper towel, and right after you apply it come back with a clean paper towel..that will clean it...but thats after you sanded, scuffed primed and got it read to paint...

If the paint is chipping off then you might want to pay more attention to sanding better..