SirRevvs

I have a 94 ex Civic with a B18A1 (non OBD) and a chipped P75. I did a search but it seems like most people have a problem with a high idle when its cold outside. My problem is when my engine is cold and I start it up it idles really low, about 500rpm and the car shakes like the engine is about to stall. If I give it some gas (kinda bogs out) for a few minutes until it reaches optimum operating temp the idle will level out perfect (about 800 rpm) and it runs great. So what would cause a really low idle when the engine is cold. Maybe the FITV, but from all the archived posts I've read the FITV always causes a high idle problem. Would it have anything to do with a chipped ECU? Maybe the IACV. I'm not sure but if anyone else has ever had this problem your advise would be very helpful. Thanks

-Chris

Filthy Focker!

Could be a bunch of things. What happens when, while idling, you turn on the AC/heater? Does the idle go up a bit.

If not, you may well have a defective IAC valve. Is your check engine light on?

fs

SirRevvs

No CEL and when I turn the A/C on the idle just gets even lower. Not real sure about the heater, but I don't think it affects anything.

Filthy Focker!

Well, if it get lower, than i could very well be the IAC valve.

I would first disconnect the battery for a while to reset the ecm
then turn off all electrical components
start car and keep at 3000 rpm until the fan comes on
then let it idle for an additional 5 minutes.

This makes the ecm relearn the idle.

then if the idle is still low, measure the resistance of the valve and compare it to a known good one.

If it is out of whack, replace it.

fs

SirRevvs

I've already reset the idle three times and it still does it. About a month ago I did an idle adjustment because the engine would idle at about 1200 rpm (at operating temp) and it was too high, but when I started it cold the idle was fine (before the idle adjustment). It just recently got cold here in Texas so I'm not sure if it's the idle adjustment I made or if something is just messed up and the cold weather is affecting it. I will check the IACV though and compare the resistance to another properly functioning IACV. So you don't think it would be the FITV right?

Filthy Focker!

Hard to say, unplug it and see. If the idle goes wonky, then it is working properly, if not, then you may have found your problem...

Hard to say when i am not in front of the car.

fs

SirRevvs

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by filthy_shovel &raquo;</TD></TR><TR><TD CLASS="quote">Hard to say when i am not in front of the car.

fs</TD></TR></TABLE>

Yeah I can completely understand that, thanks for your input though, appreciated I was just kinda looking for a general area to start diagnosing the problem. Can't look at it right now anyway (I'm at work)