Testing ISC...

infusion · 06-01-2007, 07:28 PM

hey guys how do i test my ISC???

i dissconnect the power from it and there is no noticible difference with reving and idleing with a/c on...

i then took it off cleaned it ( already looked pretty clean) put it back on.. no difference..

Reason why i think it may be faulty is, when i have a/c on it doesnt idle very well and after reving the car when its dropping back to idle it nearly stalls (its manual btw)

it also doesnt idle very well on startup.. for the first 15 seconds or so though...

any ideas? cheers!

Christiaan · 06-01-2007, 08:07 PM

Just replace it with a different ISC.

If it still does the same thing, your ECU might have a crook Idle circuit.

BLKPHN · 06-01-2007, 08:11 PM

and its not un common.^^^

89 S-PACK · 07-01-2007, 01:12 AM

try swapping the map sensor too, the one on the firewall.

i was having the same issue and i swapped mine just for the hell of it and it rectified the problem straight away. mine idled on petrol like ****. but on lpg it wouldnt idle at all. but now it idles like a dream and starts first kick now aswell. and im no longer blowing massive amounts of petrol smoke anymore on cold start

DEVL-XR · 07-01-2007, 01:45 AM

my car does this too, especially when i disconnect the battery and re connect it, takes a few days for the ECU to re learn the idle and in the mean time idles like ShI T

poomba · 07-01-2007, 10:27 AM

first try this:
http://www.fordforums.com.au/showthread.php?t=80624

otherwise, you can diagnose both the map and idle circut through the diagnosis port. all you will need is an LED or test light.

code: 126 and 129 = MAP malfunction
code: 411 and 412 = base idle irregularity
code: 172 and 123 = o2 sensor

if you need to know how to diagnose, i can make a tutorial, but it is lengthy. my seggestion would be to buy a gregoreys manual. it's all in there. worth every cent.