wondering if anyone has any ideas car will idle at around 600rpm and will idle at 1500 rpm anywhere inbetween it hunts up and down. I've pressuresised the system there are no vacume leaks changed fuel pump fuel filter and fuel regulator and no change also when it's hunting it's going lean and putting fuel in those areas doesn't help

 

also idle valve is unplugged

 

...is it same while cold or hot engine...?if so you might have tps set up issue..

 

same hot or cold it on aftermarket so can calibrate the tps to anything so thats not the problem. thanks for the suggestion

 

It's not TPS due to the fact you state it's the same with the ISCV disconnected, therefore you have an air leak, check gaskets (i.e. plenum).

You can use WD40 to trace, if need be.

Martin

 

 

let us know how it went at the end..

 

it's not a air leak as I have pressurised the intake system and there is no leaks. the map areas were it's hunting I've added fuel removed fuel added ignition removed ignition nothing helps could crank sensor or cam sensor gap cause this sort of issue

 

 

it's only disconnected to set base idle but as it's hunting I can't set base idle it's a visious circle lok

 

think it's the cam sensor gap you can see the voltage dancing about on the ecu software

 

Could be the coolant sensor in the cylinder head

 

Worth a check of the voltage at pin 20 of the ECU, ensure its very close to battery voltage which should be in the 14v range ideally.

 

had a play with it today closed the gap on the cam sensor and played with a few settings and it now idles as it should. thanks for all the help and suggestions

 

Nice when it all gets sorted out fairly easily.