As a lot of other people on here my car has a rough idle, it intermittently drops every now and then or misses. But every now and then its almost to the point that it stalls. Even sometimes when I go to slow down and I put my foot down on the clutch, the revs have just dropped straight down, it shudders and then comes back up to idle.
It happened today again when I was coming up to a corner, but this time it was longer and the car really shook and almost stalled and this was at about 40km/h when putting the clutch down.
Does anyone have any idea what the problem maybe. I've had two different mechanics, A Ford Specialist and Ford themselves say they've run computer tests on it and they both said no faults came up, which doesn't seem right

base idle set too low? vacuum leak? leak on the intake manifold? reset the ECU?

have you an aftermarket cam in it at all?

have you disconnected the battery at all? after i disconnect the battery on my EBII, i have to 'reset' the idle... by letting the car idle for at least 1 minute or so, then switching off the car, pressing my foot flat to the floor on the accelerator for about a minute, then turning on the car... it fixed mine anyway

Is this for auto's and manuals?

I have an update though. When I hopped in the car at work when it was cold, if I tapped the accellerator at idle quickly, the revs would rise then come down below idle. Almost as if it misses when the revs come back down to idle. BUT THATS ONLY WHEN IT WAS COLD, it has done it when its warm though.
When I got home but, I noticed that the engine temperature was up a bit more than normal, and I hadn't even thrashed it or anything. The temp has never been up that much before. Its not looking good, I just did a head gasket earlier this year

I think it would be great to get a definitive resolution for this problem. We need to get together with each other, mechanics and specialists to thrash out a fix once and for all. It really is a common problem and a fault lays somewhere, in the car.

Causes I've heard:

- Sticky ISC <- they can't be all sticky, even my replacement didn't fix it.
- Faulty drivers in the ECU and that it needed changning <- Maybe?
- Dirty injectors (It's a known fact the I6 idles poorly with dirty injectors)

Someone want to add to the above?

Last edited by Kit on Fri Nov 04, 2005 7:10 am, edited 1 time in total.

i've had this problem too with my xh.
i've changed over to the bbm setup with standard comp. still the same. put el xr6 comp in, still the same.

love to know a solution

I can set my idle up to 750rpm or 800rpm, and the idle improves out of sight. The only problem with doing that is it causes flaring and hanging on secondary startups, and a fast speed in idle. I can travel the first 1 km on the way to work from home, with my foot off the accelerator

But as soon as I got my mechanic to try and solve the flaring revs, he adjusted the rpm back down to Fords specs, 600 to 650rpm and solved the flaring and high idle completely. BUT NOW it's back to lumpy and rough virbative idle at lights in drive. The engine hates it at that rpm.
Almost like a cylinder drops out or an injector quits working until I get on the pedal again. Which may even be the case.

I've added another possible cause to my list in previous post.

Mine only does this when iu've had the battery off - leads me to think it's an ECU issue. I'm guessing it's the ECU relearning. After a while the problem goes away.

Sounds like a fuelling issue. A vacuum leak will have no effect on the running of the engine if that vacuum leak is common to all cylinders. I.E. if your booster vacuum hose is leaking, you won't be able to pick it up from the running of the engine.

However, a manifold leak @ 1 or more cylinders will affect the running. Get some CRC or WD40 and spray it where the manifold bolts onto the head one cylinder at a time. If the RPM changes or idle quality changes in any way, you've got a manifold leak.

My manual EFII does this on LPG. It won't run on petrol atm, but it didn't do it on petrol when it did run on petrol. Yikes, that was bad english.

Now, I have no doubt that the ford ECU is a piece of s**t when it comes to the ISC. Why do I think this? I can be sitting @ the lights with the engine idling @ 700-800 RPM and for no reason at all the revs will fly up to 2000-2500RPM. Only thing that can do this is the ISC controlled by the ECU. So, it *could*" be an ECU/ISC issue, but if the base idle is set right, then there is physically no way the idle speed can drop below base idle because of an ISC issue. Only fuel and/or timing changes will reduce idle speed below base.

Edit: And just because a diagnostic doesn't show up any error codes means nothing but the fact that the mechanic hasn't investigated the problem. All s/he's done is a diagnostic check. An ECU can't possibly return an error code for every single little conveivable issue that's wrong with the car.

I've NEVER seen a Holden ECU, for example, return an error code of "This car is a piece of s**t" when anyone does a diagnostic. Ergo, an ECU can't detect every fault in a car.

i had the same problem, mines an auto. when it was warm and id stop at the lights it would stall, wouldnt start back up. few hours later my engine went!..

when its cold it was cold, it idled fine through all gears, when warm is misses and idle varies from 600 - 800 and sometimes 600 down to 500 then stalling.

anyways my engine is now stuffed, engine is knocking, crank pulley is wobbling like crazy!..

dont know if that helps at all, just thought id share

good luck with it! it really sucks, i know how you feel.

It was actually plugged into an analyzer at one point and had the car fully checked over by hand
the problem has still not be named
I want to be able to just hear of a good mechanic who can find this f**k problem and just fix it already, but I don't really know any decent mechanics round perth. Might have to call some mates

I am having the same problem with my 1991 EB Fairmont. It has a reconditioned motor that has done just over 10,000 km and mine actually stalled the other day.
I was slowly moving forward behind a semi and then the car hesitated and then stalled. It re-started OK and did not occur again. I have experienced like all of you where the engine drops past its idle speed, but picks up really quickly. It is almost like the computer can't cope with the quick change in revs !!

I wonder if those people with aftermarket ECU's are/or have experienced the same problems or notice a distinct difference in the idle/running quality? Perhaps the moderators could be convinced to post a survey form with some of these questions in mind - pre and post modifications? It could make for some interesting statistics.

my ea had that problem and i fixed it by going back to regular unleaded,,never had the problem since...

my el does same thing as everyone elses here with the idleing, but the stalling only happens when my fuel is at a quarter or lessof a tank, or when i use 7\11 or sum other s**t petrol. i try and use bp ultimate when i can and it seems to run better