I've got a 2004 Civic EX that has a intermittant problem that I can't seem to figure out. It only happens during the heat of the day (usually around 85 degrees or higher) and this is what happens... I can start the car and drive away just fine, but after a couple of minutes, the engine light flickers, the tach loses power, the A/C will not blow cold air, and the engine acts like it wants to stall and will not allow me to accellerate. I also hear a relay clicking behind the glove box.This all happens in a fraction of a second and then goes back to normal. this will happen about a dozen or so times before it finally stays that way, forcing me to pull over and shut off the car. Shutting off the car for about 1 minute usually cures the problem until the next day where it happens again. As previously stated, it only happens during the heat of the day. I used a code reader for numerous days and waited for the problem to manifest. With the code reader properly linked; the ECU failed to produce any codes when the problem occured. In fact the code reader would lose the link to the computer when the problem happened. I'm guessing that since the ECU is not spitting out any codes, that it might be the ECU itself. Any ideas??? BTW where is the ECU located on the car??

 

Could very well be an intermittant power or ground connection problem.