Hey guys.

As some of you may know, my EF has had a few mild issues that I've had over the last year tomorrow and one of them has become major.

It developed a low idle when in gear months ago (pretty certain it only happens when the engine reaches operating temperature), so the car would be 200RPM below than what it should whenever at a stop in gear. Also after driving/being revved/started the car wouldn't drop to idle speed, instead it would drop below idle speed, run rough as guts for a split second and then bump itself up 200RPM or so to the correct idle speed.

Now today it was a lot worse. I'd Start it it'd drop much more and almost die (300RPM or so), then go back up to normal idle but then drop again, then it ran as high as 1000RPM for a bit then it tried to return to idle and went to 300RPM again. Wouldn't go in gear without stalling, I had to N bomb it at 1000RPM+ to keep it above 500RPM.

Whilst driving and in idle, the car was lumpy as hell and the driveline felt very rough too (Seen a few E series do this but we just scrapped them as they were bombs anyway), and there was strong fume like smell coming from it (exhaust not motor), couldn't tell you what it was but it wasn't oil. It felt like there was no idle, just lumps. It was literally just able to limp home. I also had to push the accelerator in 10 times more than usual. I had to start it with the accelerator slightly pushed in, It cut out 5 times on the way home (800 meter trip) and would only start 1 in 4 times or so. I had to have the accelerator almost flat to the floor just to get anywhere like it was choking or something.

Around 3 weeks ago my car started getting a shudder/pulse/quick rumbly vibration when cruising at 1800RPM-2000 on the freeway.
The problems that occured months ago were: Hard start, bad economy, bad response/low power under 3000RPM, and the idle always going low when putting it into gear.

The temperature gauge on the cluster also isn't working, this happened tonight exactly when it stopped starting, they must be related, (it was simultaneous)?

Now the punchline is I need the car for work tomorrow (drive on shift), any help would be very very very greatly appreciated!

Thanks
Would anyone have any idea what is going on?

ISC drive circuit is failing in the ECU due to bad earth track which would also cause the earth trigger pulse ECU-coil pack to play up aswell. Have you got a multimeter yet too check the ECU output voltage?

When my ECU was playing up the car would not idle cold, had a huge flat spot at low revs and the auto gear changes were wierd on down shifts 2nd-1st mainly and it would hold 3rd gear for a long time on the highway before going into 4th.

Since changing the ecu everything is back too normal. ECu just didn't fail overnight, got progressively worse over a period of 3months.

Trusty gregory's manual and a multimeter diagnosed the problem very easily when it started too play up every morning. Before that it would sometimes start fine for a week or so and then play up, so i was chasing a red herring then..hard too diagnose...

cheers...

Last edited by EL___Fairmont on Sun Oct 31, 2010 3:00 am, edited 1 time in total.

Thanks heaps for the help!

No I haven't got one unfortunately.
Will this show up in fault codes/engine diagnostic test?

What other symptoms can a failing ISC circuit cause?

Also can effect the negative trigger to the coil packs because they use the same earth track on the ecu.

nup all fault codes came back clear with codes {111} hard memory and running tests (no faults)

EF ecu's are known to play up a fair bit even more so then the EL ecu's. Do you know anyone with an EF you could just swap them over too test.

not a ghia ECU (mines a tickford motor), will a fairmont or gli one do?

yep as long as its for a EF auto and it's only for testing purposes. Since your ecu will have auto changes for a 3.45diff etc the gears changes might be off a little but engine management side of things it will prove whether or not the ecu is the culprit.

I ran a EL gli/futura ecu in my fairmont and it worked okay.

Strong fume like smell... aint that MAP sensor related?