Eratic idling and ALMOST stalling!

[Fuserleer]

Hi Guys,

I have a rather annoying problem with my valver gte (astra).

Its suffering from an erratic tickover and almost stalling, for example.

when sitting in traffic, it'll be ticking over at about 1000rpm, with the odd bad fire, then it'll drop to 500 rpm, then rise back to ~1500 and settle back at 1000 again.

when pulling off, if I dont raz the nuts off it, and do a grandad start, its splutters, almost stalling then, past about 3000rpm it all comes back.

another thing, its really lumpy to drive below 3500rpm.

ive replaced leads, airflow meter, plugs, dizzy, rotor arm, coil, any other ideas what it could be?

Im about to try the breather mod on it, but thought I might as well post this here and see if anyone else had these problems.

BTW cars got a piper induction kit, Magnex system, and cam'd (stage 1 cams).

Also when started first thing in the morning, its prone to cutting out for a few minutes.

Its been doing this for about a month and im at my wits end!

Cheers

Dan

[daveybuc]

could be your tps switch on throttle body.cav 2.0 is the same check that.also have you checked your air hose coming off throttle bodie.the big hose connecting air box these tend to split and cause havoc.

[apexsyle]

one thing which you should try which might or might not work but definatly worth thring is getting some carb clearer and cleaning out the idel control valve which you can find just under the inlet manifold.

while your at it you might as well spray some in the inlet manifold as well.

[Joekont]

Sounds like classic Idle Control Valve probs to me!

[Fuserleer]

Cheers for the replies guys, so just take off the Idle Control Valve and give it a good clean? thats it? or need to buy another one?

worth doing the breather mod too? I get kangaroos BIG time at 2k off throttle coming down revs.

[SimonP]

Take the idle control valve off, spray it full of Carb cleaner, drainout and keep doing it untill the stuff that comes out isn't black anymore. They glog up with tar and 5hit.

Refit, you may find crap comes out the back and it takes a few turns of the engine to start it, but once it's clean, it should stop any bad idling or rough start ups.

Wouldn't even contemplate buying a new one unless you have got £110 that you've got nothing better to spend on.

[Fuserleer]

k, thanks for the info, I'll give it a try this weekend and see how it goes.

£110, erm, yeah Ive got plenty of other things I could think of spending that on!!!!

cheers

[Madras_GSI]

Sorry to sound dumb (wouldn't be the first time )

but where exactly is the idle control valve, and what does it look like?

Cheers
Adam

[JamesG]

it's below the inlet manifold..

there's a rubber pipe that comes out of the SFI box on the right hand side, that goes down and under the inlet manifold..

follow this round and it will lead to the idle control valve...

[SKAMAN]

under the inlet manifold two pipes one connecter, small cylinder, pipe on end and on top at right angles.

Rather than remove it which is a pig you can remove the plenum (sfi box) clean up the throttle plate and squirt loads down it, but this may only be a temorary fix, you will find it will struggle on start up initialy then start loads o revs will cause it to burn off lots of whiteish smoke then your problem should be gone.....

[Madras_GSI]

Cheers James