My 90 Honda EX (125,000mi) is acting termpermental. Every few days I go out to start the car, and it cranks but won't fire up. If it doesn't fire up the first time, I have to let it stand for at least 5 to 10 mintues, no shorter, and it most often it starts fine. Other days I go out and it fires up straight away. What gives, any ideas?

 

Sounds like the Main Relay to me. Listen for the fuel pump to cycle when you turn the key on. If you can't hear it, have someone turn the key on with your ear at the fuel filler. The relay is about 50 to 60 bucks at Honda. Take a few minutes to replace. Under the dash on the drivers side. BTW, take the old one apart and smell it, if it smells burnt, that was it.

 

main relay

 

So you're saying if the fuel pump cylcles than most likey it's the main relay, and if it doesn't I might have a fuel pump issue?

 

The main relay controls the fuel pump, so if you turn the key and the fuel pump does not run, then the relay is (99% likely) bad. Most likely is the relay though

 

Yeah, it sounds like your main relay needs to be replaced. The main relay doesnt just control the fuel pumps power, but it also controls your entire ignition system. Sometimes the ignition alone can go out, sometimes the fuelpump can go out, or sometimes both go out. Its like around $50 for a mainrelay, if you can install it yourself.