Hey guys, forgive me for this post in advance. It's 107 degrees outside and I really am not interested in poking around with a voltmeter under my dash and engine bay outside roasting my *** off.

Long story short, when its hot outside, my 97 civic won't start. Its running a chipped p28 with lsvtec swap. It only appears to happen when the INTERIOR is extremely hot. It will not start when parked outside in the heat with the windows up. I can beat the **** out of it on the track all day long, even in 100 degree weather without issue. But the minute its parked in front of my house and not driven at all, it refuses to start if its hot.

Its not the main relay, tried a new one already. I'll try a second new one if I have to. Key on power, battery light, fuel pump works. Cranks over and over but simply will not start.

Engine bay is a solid 20-30 degrees cooler right now and the fact that I have zero issue when beating the **** out of it on the track tells me its probably not the distributor or related to engine heat.

Am i looking at a bad ecu?

Any tips would help before I start dicking around with this thing in this ridiculous heat. Thanks!

 

Try another ECU and see if the problem goes away.

 

This may sound silly, but next time you park your car in the heat, take the ECU out with you and bring it inside. Plug it back in when you next go to start the car.

If it starts right up with no problem, then there's probably a weak solder joint or something on the ECU board.