High tickover

[johnny]

My Silvia is suffering from the dreaded high tickover but only when warmed up, cold is around 800 rpm and warm around 12-1300 rpm. After searching through the forum it seems this could be caused by an air leak. Is there any way to check this is the case by removing and blocking a pipe etc. On mk1 Escorts I've had in the past we sprayed wd40 around areas we thought might be leaking air and the tickover would alter if this was the case, would this work on a more modern car such as the Silvia?

Or could it be something else due to it only doing it when warm, a cold start sensor not turning off or bad connection? Or is there simply a screw for altering the idle when warm.

Sorry for all the typical newbie questions

[datdrift]

there is a screw on the inlet manifold for altering the idle, but it sounds like one of your sensors is not working, try giving the connectors a wiggle and see if it makes any difference?

[northerner]

Like you said could be the Choke sticking open !!!

[wacomuk]

you can check for leaks using a gas, less messy than wd40

there is a sensor on the inlet manifold side that gets blocked this can caues high or low idle

[johnny]

Thanks for all the replies, I'll have a poke around the engine bay at the weekend.

[30psi]

Its probably an incorrectly setup throttle position sensor

[johnny]

Thanks 30psi, how do I adjust the TPS?

Is it just a case of winding a screw in and out or is it a little more complicated?

[30psi]

You adjust the pivot of the sensor so that the switch is shut at idle. As soon as the throttle is lifted off of idle the switch is opened.

There is an idle adjustment screw but I would check the above as its usually not setup properly if the throttle body has been removed.