Have I Wrecked my IAC?

sly · 27-09-2007, 03:48 PM

A few weeks ago I cleaned my throttle body and IAC. Due to the gas mixer I took the TB off the manifiold to do the job. Ever since, the revs drop too low when coasting or braking to a stop, they drop to 400 rpm or less once the revs get down to 1000 or so, it's an auto BTW. On petrol the revs usually recover after stumbling a bit and it idles OK, but it stalls on LPG almost every time, consequently I have to remember to switch to petrol coming up to intersections etc. Have done ECU reset but no difference.

It seems almost as if the IAC is not opening quickly enough or is sticky. Is this possible, can I test it? What sort of life should I expect from an IAC? Mine has 320,000km up.

daz_ · 28-09-2007, 12:23 AM

Pulled the manifold off? Is there an air leak or something?

au2sw · 28-09-2007, 05:51 AM

are you 100% sure that you put everything back on exactly the way it came off? earth strap on, all vacum hoses still connected, LPG feed line still in position.....that sort of thing. I would honestly go over it thoroughly to make sure everything is on properly before thinking about changing the IAC.

LPGUTE · 28-09-2007, 08:25 AM

is IAC the same as ISC? my car do the opposite to your the rev jump to 1800rpm.

FGII-XR6 · 28-09-2007, 08:30 AM

if you pulled the throttle body off did you replace the gasket? you may have a leak there with it running listen carefully see if you can hear a sucking noise. pour a bit of water over the throttle body area and see if there is any change, if there is it is a vacuum leak

sly · 28-09-2007, 12:49 PM

Quote:

Originally Posted by LPGUTE

is IAC the same as ISC? my car do the opposite to your the rev jump to 1800rpm.

Yes same thing.

sly · 28-09-2007, 12:51 PM

Double-checked connections etc yesterday, all good. Will do water test later today & see what happens.

sly · 28-09-2007, 10:07 PM

Read this thread http://www.fordforums.com.au/showthread.php?t=114646 and remembered that it's not switching over cleanly to LPG when cold now like it used to. It takes a bit of a rev on petrol before switching over otherwise it stalls when the gas kicks in. Maybe time to clean out the converter, it's done 4 years and about 130,000km, can't complain too much.

EX-Y494 · 29-09-2007, 12:07 AM

The best way I know of if the ISC is working is to have the car running then unplug the ICS and if the car stalls it working if the car dosen't stall it not working.