Abf over revving idle valve fully open.

Driving home yesterday my revs shot right to the top and won't come down. I have put my hand over throttle body but didn't cut out so assume it's drawing air from somewhere else but the only other pipe I can see is the one from the servo and that seems fine. Can someone point me in the right direction please.

rubjonny please look at this one for me. Had aa bloke out and didn't have a clue but disconnected the idle control valve and will run normal but not tick over. If I plug it back in goes strait to 5000 revs. It vibrates as it should and the slider inside moves back and snaps forward. Do you think this is the problem and needs replacing?

Worked out that the valve is just fully opening it's self open.

If I put a bit of tape over the end of the valve it will idle. So as the valve isn't stuck open as the plunger closes when engine is turned off is it more likely to be coolant temp sender?

Anyone,  need to drive it tomorrow

Sounds like idle control valve to me, can't see why a coolant temp sensor would tell the ecu to change anything other than the choke…

jusdubbin said

Sounds like idle control valve to me, can't see why a coolant temp sensor would tell the ecu to change anything other than the choke…

Is there a choke on this. I thought that's what the idle valve did or I could be wrong.

AFAIK the idle control valve will control an electronic choke. MAF values will dictate the A/F ratio but if that goes wrong it will just run a baseline figure which may make it run lumpy but won't make it rev like hell. Coolant temp sensor is just another input for the ecu so it can slightly adjust the A/F ratio until the car is warm, but again won't make it rev that high.

If it goes to 5k with the ICV plugged in, and runs fine without it (albeit it won't idle) then there's your problem…

If you desperately need to drive it a short distance as is without changing anything then I'd personally unplug the ICV and use your throttle to keep it idling, but I cannot take any responsibility for anything should you choose to do this, it is at your own risk!

jusdubbin said

AFAIK the idle control valve will control an electronic choke. MAF values will dictate the A/F ratio but if that goes wrong it will just run a baseline figure which may make it run lumpy but won't make it rev like hell. Coolant temp sensor is just another input for the ecu so it can slightly adjust the A/F ratio until the car is warm, but again won't make it rev that high.

If it goes to 5k with the ICV plugged in, and runs fine without it (albeit it won't idle) then there's your problem…

If you desperately need to drive it a short distance as is without changing anything then I'd personally unplug the ICV and use your throttle to keep it idling, but I cannot take any responsibility for anything should you choose to do this, it is at your own risk!

Great stuff. What I have done is put a bit of tape over the end of the valve and poked a hole in it which is now running on a tick over in a fashion. Got me thinking could I just remove the idle valve completely and put a idle screw into the throttle body?

Better to replace the ICV, it will give different readings dependant on atmospheric conditions and engine temp.. An idle screw will work but you'll forever be making minute changes from day to day if it's hot/cold, dry/wet etc…

jusdubbin said

Better to replace the ICV, it will give different readings dependant on atmospheric conditions and engine temp.. An idle screw will work but you'll forever be making minute changes from day to day if it's hot/cold, dry/wet etc…

Will do then. If I get one tomorrow do I just plug it in or do I need to do anything else with it? Ps thanks for your help.

Just plug and play brother.

jusdubbin said

Just plug and play brother.

Brilliant. By any chance do you have parts numbers so I can quote my local motor factors.

Not to hand but it'll be stamped on your one anyway, just whip it off and have a look, should only be a couple of screws

Cheers pal

037906457D is what it should be, just sounds stuffed to me or its the wrong one for the car

rubjonny said

037906457D is what it should be, just sounds stuffed to me or its the wrong one for the car

Cheers pal

Ordered one today from veedubbmachine so lets hope it does the trick. Also they said its good practice to change the ecu temp sensor at same time is this correct as sold me one of these!!

If it was me I'd fit the ICV first and see what difference it makes, then make a judgement call on the temp sensor, if it's cheap then you may as well replace it because you won't worry about it going 6 months down the line (always a possibility) but if it costs a bajillion dollars then send it back…

Shouldn't cost much so if it's ordered you may as well fit it for peace of mind.

jusdubbin said

If it was me I'd fit the ICV first and see what difference it makes, then make a judgement call on the temp sensor, if it's cheap then you may as well replace it because you won't worry about it going 6 months down the line (always a possibility) but if it costs a bajillion dollars then send it back…

Shouldn't cost much so if it's ordered you may as well fit it for peace of mind.

Only cost 6 quid so will put it in!!!