Hay all

I cleaned my girlfriends throttle body out a couple of days ago with carb cleaner on a V6 TF. Ever since i have done it the idle wont go below 1rpm in park or neautal but in drive or reverse its perfect idling. I took the battery cable off to reset it and took it for a good drive still it wont go below 1rpm can anyone help on wat the problem is?

Thanks kurt

there's a idle screw on top of the TB which you can turn down which will adjust the Idle

the idle speed is set by the ECU, so it will correct itself if you adjust the screw, you need to set it properly, there is a how to in the workshop manual.

there's a idle screw on top of the TB which you can turn down which will adjust the Idle

If you Didn't touch the idle screw before doing this, why touch it now? Its only covering up another problem.

;1309401']If you Didn't touch the idle screw before doing this, why touch it now? Its only covering up another problem.

I'm not sure how the idle is maintained in these engines, but I would assume the ecu could only modulate the idle to a certain extent? A couple of hundred rpm or so? The idle screw would set the base range by allowing a certain amount of airflow through the throttle body to keep it around 800rpm or so and the ecu would make correct adjustments from there based on actual air mass?

If this is how the system works, I don't know if it actually is that's just my thinking of it, then I would make sense that as the throttle body gradually became full of oil residue over the years that would slowly reduce airflow and as such the idle speed, so if every 6 months or so during a service the mechanic noticed it was low and wound out the screw to adjust up the speed once all the gunk was cleaned out it would be allowing far too much air flow through and even with the ecu trying to drop the speed down it still needs to keep the air fuel ratio within limits.

So seeing as the throttle body is now working at it's original efficiency again the screw would need to be wound back in to set everything back within limits

I'm not sure how the idle is maintained in these engines, but I would assume the ecu could only modulate the idle to a certain extent? A couple of hundred rpm or so? The idle screw would set the base range by allowing a certain amount of airflow through the throttle body to keep it around 800rpm or so and the ecu would make correct adjustments from there based on actual air mass?

If this is how the system works, I don't know if it actually is that's just my thinking of it, then I would make sense that as the throttle body gradually became full of oil residue over the years that would slowly reduce airflow and as such the idle speed, so if every 6 months or so during a service the mechanic noticed it was low and wound out the screw to adjust up the speed once all the gunk was cleaned out it would be allowing far too much air flow through and even with the ecu trying to drop the speed down it still needs to keep the air fuel ratio within limits.

So seeing as the throttle body is now working at it's original efficiency again the screw would need to be wound back in to set everything back within limits

Ok so your are saying i should adjust the idle screw to noraml idle rpm?? It sometimes sits on 1rpm and sometimes just above.

I'm not really sure, Im just assuming that's how the system works, someone who knows a bit more about these cars could probably confirm wether or not that's the actual case.

Well i found out my idle should have gone back to its normal idle after the clean. It idles at 1rpm or just above in park and pritty much normal in drive or reverse. So i put another isc motor in the car and the idle is still the same. Someone else told me its the air idle valve. Is this replacable or fixable??

Well i found out my idle should have gone back to its normal idle after the clean. It idles at 1rpm or just above in park and pritty much normal in drive or reverse. So i put another isc motor in the car and the idle is still the same. Someone else told me its the air idle valve. Is this replacable or fixable??

Bump.? Aswell i noticed if i let the car cool down for about an hour the idle will go down to normal and when i heats up to operating temp it will go to 1rpm or just above again.?