I have a 1991 civic dx with FI that doesn't seem to want to start
when its hot. this problem just started after i replaced the radiator but i can't think of any reason why this would affect it. If you leave it sit for 10-15 minutes it will start right away. any suggestions as to something obvious that i may be missing? thanks in advance.

 

It's the Main Relay. Hondas old ones suck ass. Mine did the same thing. To know for sure turn the key to ACCII, if you don't hear the fuel pump come on it's probably the Main Relay since it turns on the Fuel Pump and Injectors. It's $41 at the dealer.

It's located behind the coin box right above the hood release lever. Takes a 10mm socket to get it out.

 

4gh is right, my 46h does the same thing.

 

Great!!!!!!!!
My car's been doing that to me on hot and humid days and I never found out what it was... Thanx guys!!!

 

if that's the culprit, its supposed to be hot today so it should act up on me. if it does i have a product called "Freeze Spray" that should cool the relay off enough to allow it to work again. thanks for the help!!!

 

Eh it might work, but mine used to die after I had been driving around for a while. And I know the temperature inside my car wasn't that high.

 

yep, it was the main relay. i'm going to take the old one apart and
see if the relay thats built inside the module is actually replaceable. Being an electronic tech maybe i can replace it for way cheaper than it cost to replace the whole module ($75 cdn)
thanks for the help!!!