I need some help with diagnosing a starting problem for my friends '90 Prelude 2.0Si. The car starts great in the mornings, but after it's hot, it may or may not start again. This also happens if it's very hot outside, and it's parked in the lot all afternoon. If cranked often and long enough, it will eventually start after several minutes of effort.

There are no CEL, and the car runs great once started. My thought was the fuel pump wasn't holding pressure, or that there was vaporization in the fuel rail, but I'm really not sure. Is there a cold start valve on this engine? Any ideas?

Thanks!

 

Sounds like the main fuel relay, as they begin to go bad they become very sensitive to heat. Also, once they finally close the car will run fine like you describe. I think the part is 50-100$ and is under the dash somewere. Goodluck.
-Mike-

 

Thanks, I'll have him check/replace this.