Hi all, I have had a bit of a read around and tried many things and now am stuck getting this thing to idle right!

Some background;
It’s a 4lt 6cyl hybrid motor ford falcon EL (ford AU head) with a wade AU1671 and pacemaker extractors (4480). The car also has a J3 chip fitted too.

What it does;
At idle it will hold idle ok for a few seconds and then feel like it misses and the revs drop then the idle speed motor picks up the revs to stop it from stalling. Sometimes it does stall. Doesn’t do this when cold or at cold start. Idle gets crazier as it gets warmer / operating temp. Car drives very strong otherwise only issue at idle.

What I have done;
Set base idle (2 ways not sure which way is correct but didn’t help).
1st way I put the car in diagnostic mode, waited for about 2min for the revs to drop (confirmed using timing light). Put a 0.75mm feeler gauge between the idle stop and unplugged the idle control motor. Car idled OK and set the RPM to approx 700. Turned motor off and put everything back & reset ECU

2nd way I tried was start the car (not in diagnostic mode and unplug the idle motor) and adjust to get it to idle around 550rpm or so. Then plug ISC back in. And then reset ECU.

What parts I have replaced / tested;
- New map sensor
- New fuel pressure regulator
- New plugs
- New leads
- New dizzy cap and rotor button
- Used smoke machine to see any vac leaks – all good
- New ISC
- New TPS (set at under 1.0v)
- New oxygen sensor
- Injectors cleaned and new seals on injectors
- New capacitors on ECU & tried another ECU too
- Checked for fault codes – none
- Taken whole throttle body off and cleaned it
- New air intake temp sensor
- Checked and tested cooltant temp sensor - OK

Car still has this miss or hunting behaviour even if the ISC is disconnected. I have tried it without the J3 chip and it still does the same thing. I found the purge valve was shot (not working) so it could have been drawing too much fuel vapour wrecking the idle. I blocked it off to test and not much change.

Only thing which looks a bit funny is the timing? I know the ford falcon EL is suppose to be 0 deg or +- 2deg from TDC. When I set the car in diagnostic mode the marker is a good 2cm to the LEFT of the mark on the case. So I’m guessing that’s 10deg BTDC? It doesn’t ping whilst under load or WOT and runs ok while driving?

Out of ideas what to test or check next?

YouTube clip below to show you how it looks/sounds

https://www.youtube.com/watch?v=u2BF3ZcqHAY

cheers

When i first got my j3 my car would surge, act weird and it turned out to be a faulty ECU.

Like you tho, after i replaced it i still had a strange idle for the last year and a bit.. My head gasket failed me recently so i went about lapping my valves and found a bent no.6 intake valve.

Maybe a leak down test wouldn't hurt.

Thanks for the tip. The engine has had a full rebuild recently (about 25,000kms ago). full top and bottom end.

Before the rebuild the head gasket went (common for the EL) so to save time I got a new head and transferred the rocker gear and cam, valve springs etc into the new head. Little did i realize this was a cheap Chinese head and the tolerances were not 100%. It ran fine for 1 week and then it started to run really rough at idle blowing heaps of black smoke and eventually it would not start again and if it did just blow heaps of fuel in the intake and shake the car violently! the spark plugs were fouled with fuel!

Took the valve cover off and cylinder 3 intake valve was bent, and then took the head and yes the valve hit the piston, cracking it so the thing got rebuilt.

The dizzy cap and rotor button says its been replaced but I doubt it or its a poor quality one. It was running 100% fine for a year only recently playing up. So I've ordered a new dizzy cap and rotor button just to be sure.

Like I said its weird, very good power while driving, idles 100% OK when cold and then when to operating temp sputters a bit once you been idling for more then 30sec in almost a predicable cycle where it feels like a cyl or 2 miss causing RPM to drop. So hope it helps!

The really weird thing with my valve was there is no sign of contact with the piston.. not a single mark, and the the other 11 were dead straight.

It's got me stuffed as to what happened there. My idle was just fluctuating around 400rpm with the occasional stumble.

an update for anyone in future. Car stalled while driving and was able to restart it when it cooled down. assumed it was the TFI module on dizzy. it in fact was the hall (PIP) sensor inside the dizzy itself. car thru code 211. that sensor was giving erratic readings causing the miss, funny idle and stalling.

instead of stuffing around got a replacement bosch dizzy droped it in, reset base timing and shes good!

did you change the drive cog over from the old dizzy to the new dizzy? otherwise you may destroy the aux gear

yeah i did think about that, but the dizzy i took off wasnt a genuine ford (motorcraft) one or bosch. it had no brand markings & was a no name dizzy. definitely an aftermarket one.

the replacement dizzy i got was a genuine bosch one so i would assume its gear is reliable? i dont trust taking the gear off a no name dizzy to swap it over the bosches. if it was the orginal ford one then yeah.

here are some pics of the dizzy... looks like the TFI module shorted or something causing the wires to the hall sensor to get hot and the insulation to melt. its a big mess in there with melted plastic. dizzy has no brand stampings on it, but the TFI module has the brand "Standard" on it.

Back of the TFI module had pretty much no thermal paste/grease.

just to let other people know

the no-name dizzy that was in prior had a steel dizzy gear.

the Bosch dizzy that went in had a bronze/alloy type dizzy gear. which i would assume is a softer metal.

I reckon I would go to a wreckers and get a "genuwine" dist. and use that gear, just to be sure. For the sake of an hour or so and a few bux................

I think Bosch are also made in China..............could be wrong tho.................

will have a look at a genuine gear.

the bosch dizzy that came in had "made in Australia" cast on its body

Them pics look nasty.

WOW!! we still make something in Oz!!