Got a EF fairmont, with 5 spd, and a AU engine in it, and for some reason the revs are really really slow to drop. cleaned the isc and tb and made no diff, reset the computer numerous times still no diff. I even fitted the stock intake and filter back on and still have the same prob (cos i got a 3" intake pipe with a K&N filter)

its weird cos u can pull up put it in neutral and the revs will sometimes take from 5 to 10 seconds to drop from 2000rpm. and the idle can be normal sometimes at 750rpm and for no reason go to 1000 or even 1200rpm.

im goin to take it to ford on the weekend and plug it in to see if there is some error codes in the system but does anyone else have any ideas that might fix the prob?

(dont have a cam or aftermarket chip in it, apart from intake and zorst and diff engine its stock)

Welcome to the world of the s**t ford ecu. Mine does the same and the solution is drilling a hole in the Idle control (ask jonno).

Or use it as an excuse to get a new pooter.

I would say it is running the auto computer, which is programmed not to drop revs of as fast as the manual (it is expecting the auto bux to be dragging the revs down as well). I was running an auto ecu while shopping around for a manual and it behaved the same

I have this problem and I have a Manual ECU.

My solution was to put the ISC on a switch, and once the car is warmed up I just don't use it at all. Idle is rock solid steady.

i got a manual ecu in it...

voxace... which wire did u wire the switch into...???

Yeah, the idle in my ute seems to act similar - drifting at different revs. Checked idle settings, cleaned ISC, etc. When doing an ECU diagnostic, code 786 Economy Indicator Lamp is always there (puzzling as it's a factory manual), despite resetting the error codes. As far as I know the car is original, but I suppose Ford could've thrown in an auto one at assy time.

If it is just the ISC being over active you can put a thin metal plate with a couple of 3mm holes drilled at the inlet and outlet holes between the ISC and the throttle body. It lets the ISC still control the idle speed - but only over a small rev range (around 500rpm) instead of a few thousand rpm.

Just any one of the ones going to the ISC, or find which one it is at the ECU.

yeah i had that problem
and i disconnected the ISC compelty.

the only con is it acts like a carby car when cold.

hey all, had the same prob in my ef, 5 speed. after 3 days at the mechanics they finally figured that the idle speed thingy was buggered put in a second hand one.. runs sweet as now!!!