Martin_vtec

iTrader: (1)

okay... so.....

I have put on 3 new iacv's and my car was still reving up and droping in idle... i also checked for vac leaks and it seems to be neither i have broguht it rto 2 shops they dont know wats going on.. so what else could this be.. My next step is taking of the intake manifold and cleaning that up cause i chacked my intake and it was like coated in mud/dirt(cold air ) so it makes sense that some of that dirt made its way up there.. but i would still like opinions on this.. i ahve also drained the coolent and re-filled.

also can this be caused by a stretched throtle cable?

91dohcvtec

I remember finding a small crack on the bottom of a plenum (had some carbon built up around it) on the intake manifold that was causing a bad idle, covered it with some JB weld and it was good to go. I don't think it could be your throttle cable either.

jayp6969

crack in the exhaust manifold which is sending a bad signal from your o2 sensor. just have a quick peek under the heat shield Honda exhaust manifold always crack

spike

Try changing your thermostat, that cause the same problem in my last civic.

Martin_vtec

iTrader: (1)

dont think its exhaust manifold got DC headers, thermostat u say eh?? that could really do this? whe n i start the car it revs like 4000-5000 for like 8seconds

chris_v2

A thermostat is not going to cause your idle to drop.

Bring it to my shop. I'll find the problem.

Martin_vtec

iTrader: (1)

thats quite the way out there... and the cash flow has slowly rained out untill payday

chris_v2

Understandable. Just trying to save you a few bucks. Don't bother replacing the thermostat (unless it actually fails a test) but this is not causing your idle issue.

Martin_vtec

iTrader: (1)

if i unplug the iacv and it stops reving up and down is that defently the problem or can it be something controlling that?