idle has gone to 3000 revs

[combine]

came back from the w. mid meet today everything fine , got those seals from Lee , cheers , started her up to pop her in the garage and the monster goes to 3000 revs , hell of a noise ! What the feck is going on I ask you !

[blaineuk]

accelerator cable stuck.

[combine]

Not 100% sure , though obviously lifted hood , pulled on cable only to get even more revs , can't think what else it could be ?

Edited by combine on Sunday 17th February 21:02

[rev-erend]

Sounds like the usual stepper motor gremlins ..

Turn the ignotion on and off a few times and see if the problem goes away.. or clamp the air feed to the stepper motor with some mole grips - if the idle speed falls then you have it.

[GreenV8S]

Is the throttle closing fully? (Look closely at the linkage and press it against the throttle stop.) Also look at all the hoses into the plenum, any air leak here would raise the idle speed. Do you have an overrun valve? If so, check it's staying closed at idle.

[combine]

Will have a look tomorrow , hope its not nasty and .... something broken !

[combine]

Started her up this morning , but put clamp on stepper pipe first , then took clamp off , staying around 1100revs which is more than she should be , think its a doggy stepper motor . Nothing up with the accelerator cable which is a pity , stepper motor's are around the £70 mark plus vat ? Presumably only one type of motor was fitted ie not a choice of 3 different ones ?

[GreenV8S]

When you squash the bypass hose flat, do the revs drop to around 500 rpm?

[odyssey2200]

you probably have an air leak into the manifold allowing unmeterd air in to the manifold that the air flow meter is not aware of.

Check all your vacuum pipes and servo hoses etc.

[combine]

GreenV8S said:

When you squash the bypass hose flat, do the revs drop to around 500 rpm?

Didn't note the exact rpm when hose was clamped , was less than 900 anyway , will check again .

[rev-erend]

When the revs keep playing up like that it's a classic sign of the stepper motor playing up.

If you keep turning the motor on and off this often resets it ..

Jules (Trackcar) has suggested blocking the feed pipe and just drill a 6mm air hole in the blockage - to reduce the amount of air that the stepper can control.. sounds good to me..

You can also block it completely and remove the wire plug and the car will still function OK but it will have more problems idling .. especially this time of year .. so it's not an ideal fix..

[combine]

So I better replace the little blighter ( stepper ) , will they have one at the local landy parts place , i'm thinking of the one just outside Desford , leics , indy landrover bits .

[GreenV8S]

They aren't cheap, so make sure that's the problem before you part with the cash. Shame to shell out and then find you've just knocked a hose of ...

Squashing the hose flat would confirm whether the base idle is right. If it isn't, you're barking up the wrong tree.

[djc1001]

Have you cleaned the stepper motor - usually clears the problem. Search on the Griff or Chim forum lots on steppers.

David

[ed_crouch]

Definitely second the comment about cleaning the motor before replacing it. Bit of STP carb cleaner, or other such Triclorethane based cleaner (well, trike's not available anymore, but whatever has replaced it...).

They get gummed up with Carbon deposits, and can make the engine hunt because it takes an overcorrection by the ecu to make the motor flap break loose from its gummed up state, which then makes it overshoot, and the whole thing starts again...

In your case, it might be that the motor is so gummed up that its just plain stuck.

Ed.

Edited by ed_crouch on Wednesday 20th February 12:57

[combine]

djc1001 said:

Have you cleaned the stepper motor - usually clears the problem. Search on the Griff or Chim forum lots on steppers.

David

Just found the article in sprint about cleaning , will give it a go !