Relocate coil off engine next to air filters a good spot.

I'd be really interested in your solution to this as I've been having the same problem with my ef xr6 since i bought it a few months ago. It started off just "hunting" where i'd just be coasting along without using any accelerator (especially down hills) it would sort of surge and jerk forward slightly.

No it barely idles and goes up and down all over the place and you can sorta feel it miss. Sometimes its worse than others - i run dual fuel and it seems noticably worse when running on petrol.

I originally thought it might have something to do with a leaking head gasket but i've since replaced that and interestingly enough it ran beautifully for a day or so when i got it back from the mechanics but slowly got worse until it had degraded back to how it was. I noticed my stereo presets were wiped so obviously they'd d/c'd the battery.

I've currently replaced the oxy sensor and the isc - i did have codes come up about the cam sensor (the leak was on that side) and i think the knock sensor. Should i be looking at replacing those first or should i be looking at a new ecu on account of the problem seemed to go away albeit intermittantly when the battery was d/c'd?

I plan to take it to a mechanics but i don't want them to just start blindly replacing things and costing me a small fortune.

Is there anyway to eliminate the above and map sensor without replacing the parts? If not are all the parts the same as standard ef falcon?

Ok have some more info. Today being kinda hot in Melbourne i was waiting in a carpark with engine idle and AC on. I noticed that the idle was rough in cycles and very constant and timely. IMO this is telling me it may be timing (knock sensor) or fuel pressure fluctuating (fuel pressure reg faulty) One more thing is that without restarting car i then drove home around the corner a bit and pulled up in Park and found the idle to be smoother but after about a minute it was fluctuating again. I think its going to be a matter or replacing the knock sensor and fuel reg to cancel them out but hope its one of them. Now i dont think a coil would do the above.

When were your injectors cleaned last?
Pull the fuel reg hose and plug with your thumb the vacuum port - does the higher fuel pressure improve idle ?? If so, the injectors will be dirty.

Fit a long vaccy hose to the fuel reg, and suck on it while the engine is running - any fuel taste means the fuel reg diaphragm is perforated.

The injectors were replaced just over a month ago which was just after this idle problem started. I just removed the vac line to the fuel reg and the revs raised cause of the vac leak. Now i fitted a length of hose to the fuel reg and sucked, there was no fuel taste nor was there any change at all in revs or idle. Could the fuel reg be jamed??

Well the idea is to pull the vaccy line off the reg, and plug it with your thumb, so there's no vaccy leak. The increased fuel pressure may cause the idle to be smoother if the injectors are clogged, otherwise, you won't see any great difference.
The sucking on the hose is just to check if the diaphragm is ruptured.

I think the only way you can rule out the fuel system is by pressure testing it - you will find it costly to find a fuel pressure gauge to read EFI pressures (around 50-60 PSI and around 80 PSI for the lock test).
I've used an old oil pressure gauge (capilliary line type)with a T piece and hoses to suit.
You can then reliably check the reg, fuel pump and it's check valve, etc.
I'm assuming the injectors are fine, so that should cover the fuel delivery.

Sometimes some crap can get through the filter and make it to the regulator and get stuck in it.

I had lots of trouble with my EF idle problem, so I ended up buying a reconditioned/tested ECU unit and buying a bottle of carby/throttle body cleaner and using the whole can in the throttle body, the car works wonders now. I changed everything i could think of, so it must have been the ECU. But does anybody know why the ECU caused so many idle problems?

joolz, im having the same problems. the car shakes and isnt real responcive when idle. havent found a cause yet either

have you taken your isc off and cleaned all the carbon and crap out of it? and cleaned the TB bore and butterfly..

have you tried increasing your idle speed slightly to smooth things out?

Yes the ISC has been done and everything is clean. Its not a matter of the revs changing as a dirty ISC would do but it more of a miss.

Check that the manifold bolts arent loose.. the thickness of the gasket allows for some compression of the gasket, and they can come loose. more often then not that can be the cause of poor idle, because they suck air in around the manifold and the engine runs lean..
common issue on BAs and etc too.. (the BAs actually put in 'tighten inlet and exhaust bolts" as a service item every 10,000kms)

Very curious as to what the solution might be as I have the same problem also.

There are no leaks in the manifold as the head gasket was done recently and new gaskets were fitted to manifold. The idle problem was slightly present before head gasket replacment (seeping coolant from number 5 water jacket and no leaking between cylinders) I havnt had a chance yet to look into this further and will have to wait till after the cruise to the island this weekend.

Grabb a Butane torch turn on the gas but dont light it up and then run the nozzle close to all intake components. If there is a vacume leak the engine will rev up with the gas intake. Also is good to find dodgy vacume hoses.