When it's hot outside (low to mid 90s), my car, 2000 HX with e-gay CAI&muffler, really hesitates when I start it, and idles pretty rough. After it warms up, it's fine even with the AC on. But if I stop the car and like go into a store, when I come back, it does the same thing again. This is the first summer with the car, so I don't know if this is a new or recurring problem.

Cliffs:Car idles rough when it's hot outside.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Ghetto Civic HX &raquo;</TD></TR><TR><TD CLASS="quote">When it's hot outside (low to mid 90s), my car, 2000 HX with e-gay CAI&muffler, really hesitates when I start it, and idles pretty rough. After it warms up, it's fine even with the AC on. But if I stop the car and like go into a store, when I come back, it does the same thing again. This is the first summer with the car, so I don't know if this is a new or recurring problem.

Cliffs:Car idles rough when it's hot outside.</TD></TR></TABLE>

Is the AC on when it does this? I had a car that would stall / not start if the AC was on until it was warmed up. Traced the problem (after 2 years) to the IACV. Check that with a multimiter to see if it's working (the specs should be in the haynes manual). If that's not it, check for vac leaks, then plugs, cap, rotor, fuel filter. Those things solve 90% of weird idle problems.

 

I don't start the car with the AC on. I'll check on all the other stuff you mentioned. I already have some concern about my fuel pump.