6 replies to this topic

[wilcooper]

Above the lost motion is a bolt which touches something sticking out of the throttle body which moves.....should this have a seal around it?

Spraying carb stuff on it slows the engine down as its ticking over fast.

Any help?

[spiguy]

Above the lost motion is a bolt which touches something sticking out of the throttle body which moves.....should this have a seal around it?

Spraying carb stuff on it slows the engine down as its ticking over fast.

Any help?

The bit that moves is the pin which is driven by the stepper motor. It moves so that it can push the throttle, as part of idle control. The pin should have a rubber boot / seal round it. I suspect from what you are saying that maybe yours doesn't, and that if you find spraying some sort of lube on it is getting it moving then maybe its 'sticky'.

The pin should move quite frequently - most noticeably if you quickly flick the throttle - it should come out ready to 'catch' the throttle lever. Also, when you switch off your engine it should move about as the stepper motor resets its position. If you want to see if the motor is working properly, put on your ignition (position 2 with the battery / oil light on) and using your thumb, 'cycle' the throttle all the way to fully open and back 5 times. This should prompt the stepper motor to reset, and you should hear the clicking sound and see the pin move about.

If you don't get the clicking then the stepper motor is not working properly - maybe due to a bad solder joint (was in my case). If the motor is clicking away happily but the pin seems sticky as it leaves the housing, maybe it can be cleaned up.

So you might end up opening up the stepper motor housing for a better look.

[wilcooper]

It does work, when idling and giving some throttle, it moves out like you say, and when ya knock the engine off it 'resets' and goes in out in etc quite extreme.

and yeah, do hear the clicking.

going down to autoworld to speak to a guy

Edited by wilcooper, 08 May 2009 - 09:44 AM.

[wilcooper]

have put a little self made seal over it, doesnt seem to do much :/

[wilcooper]

possible to get a Service Kit for them?

[KLAS]

the seal there is only to protect against dirt as there is no air connection between the stepper and trottle body. so if spraying some stuff there slows down the engine maybe its sucked in by worn throttle shaft gasket or an air leak between throttle body and manifold

[murukan]

That pin is pretty near the back, and as Carl says there is no air/fuel connection between it and the inlet manifold. I'd guess what you're spraying is going into broken vacuum hoses at the rear of the manifold, underneath the manifold through a worn seal or through a gap in the inlet manifold if it's loose.

I'd check...
Vacuum hoses.
Manifold Seal.
Underside of the Throttle body.

in that order, just because it's a *illegitimate person* to get the manifold off to look at the underside sometimes