So here's a question: I'm driving home from work one day and my '90 Accord just stops running. I came to a red light and as soon as I stopped, it shut off. Won't start back up. I've tested to see if I have a spark (I do) and I just replaced the fuel filter, which I thought might've been plugged up. Still not starting. My question is, if the main relay went while the car was running, would it just cut out like it did? Probably a stupid question but I'm relatively new at this whole DIY repair thing.

 

I'm digging way back in the memory banks here, but on my previous 90 accord it was typically a start issue. If the problem had included failures during driving, it would have been a huge recall....people would have cars cutting out on the highway. That being said, why not turn the key and see if the pump primes? That alone will tell you if your main relay is bad....on mine it was a simple cracked solder joint fix.

 

Yeah I don't think the pump is priming when I turn the key. But I don't know if it's the main relay or the pump itself causing the problem here. Any way to tell for sure?

 

All you do is check for fuel. If you got no fuel then you apply power to the fuel pump and see if you get fuel pressure(pump turns on), if yes then it's likely the main relay is bad. It won't always test bad, it needs to heat up and then it stops working so a test isn't always foolproof on it.

 

oh man, yea I forgot about the heat expanding the crack in the solder joint. My friggin car would never start on hot sunny days when the interior of the cabin heated up the relay.