Idle up and down ???

[dannyboy3767]

hey people need your help again, when i start the clio williams 3 it just dies, but when it heats up a bit it will run but the idle is going up and down a little bit. What is causing it, is it the throttle position sensor or the air flow meter. Is the throttle position sensor the little red thing on the intake manifold and how do u adjust it. thanks again

[drsmith1979]

the throttle sensor is the red thing on the throttle body but i wouldn't suggest altering it as its very sensitive and is unlikely to have simply 'moved' so to speak, have you tried your coolant temp sensor? its the plug near the distributer, id also look into the ISCV and give it a clean, its the black valve thing on the front inlet manifold.... possibly O2 sensor too, but it should still start with a bad one?!....

[bbaazz-08]

i had this before and it turned out to be the idle control valve......this is probably what you think is the air flow meter.....its to the front of the inlet manifold......they can be taken apart too

[dannyboy3767]

yeah ive tested the coolant temp sensor it seems to be ok. Yes i thought that was an air flow meter, ill try changing the idle control valve then and see what happens. Thanks boys

[drsmith1979]

Just to clarify here is a quick pic of it:

[dannyboy3767]

right lads ive fitted the new idle control valve and i have a major problem. When i start the car its going straight to 4500 rpm and staying there, i cant figure out what is wrong. the throttle is back full. I noticed the throttle position sensor only has one screw holding it on so im wondering if it has moved, what effect would it have or how can i adjust it.

[Wobba]

Check the pipes are on correctly on the ISCV. Sounds like possile air leak.

Clamp the air hose leading to ISCV, revs should die, or even stall engine, thats normal. If not, air leak somewhere eg split hose or hose not on properly.

Did you renew the ISCV or clean it? Is it defo working and not jammed open?

Check the MAP sensor vacuum hoses (small rubber pipes leading into drivers side of intake manifold, and small rectangular box on bulkhead in front on driving position).

If none of those, check that the throttle itself is not stuck open. Take off the air filter box and look at the throttle paddles inside, make sure they are not jammed open or throttle cable is incorrectly tensioned.

Whilst air box is off, start car and block the pipe that leads from the air box to the ISCV completely, mind yourself, the suction is strong. Engine should start to stall on idle. If not, air leak. Trace pipework or other areas for leaks.

Or could be faulty ECU (wet).

If none of the above try unplugging the white plug in the inlet manifold on the drivers side, start car, any change? With it off it should give ECU default reading.

Do the same with the white CTS plug in thermostat housing afterwards.

[Wobba]

Dont tamper with the throttle adjustment screw unless its a last resort.

[queegan]

Spray some brake and clutch cleaner over the pipes mentioned and if there is a leak then u will notice a change in the enigne tone very handy for finding splits or holes

[dannyboy3767]

think ive found the problem lads, it seems like there is no signal going to the idle control valve, why would this be. i fitted a brand new idle control valve but i think its just staying open too much. ive tested the new ICV and works fine when hooked up to 12v battery. if i block the pipe going to the intake manifold the car will stall and if i block 2/3rs of the hole the car will run fine so it has to be no signal going to it. would the coolant temp sensor have anything to do with it ??. i had the temp sensor out and looks like new. Any ideas.