High Idle

[cantfindausername]

Really don't know where to turn with this now.

I've just finished changing the clutch on my Toyota MR2, and now its back together I've got a few problems. The main one that I can't figure out is a High Idle. Its around 1750 rpm.

I've checked over all the vacuum lines and none of them are split from what I can see. I've sprayed wd40 over any areas that I suspected a leak could arrise, i.e injector seals, vacuum pipe joins etc.

The only extra thing I did around the intake was to regasket a blanking plate on the Throttle body as there was signs of leaking.

I would really appreciate any advice on this.


edit: A friend suggested to me last night that the heavier flywheel and clutch assembly could be the culprit for the high idle. I'd not even thought about that, but the more I think about it the more sense it makes. Heavier flywheel = more inertia in the engine, so once its spinning it wants to keep going up to a certain point. However, no matter how much of a viable option I convince myself this is, I just don't know that level of technicality when it comes to engines.

So, what effects would a heavier (much heavier) flywheel have on a cars idle? If any?


Thanks in advance.
Ant

[SteveNZ]

What engine is in your MR2?

Have you checked any basics? The throttle body needs to be closed and there needs to be slack in the cable. Check the idle up valve is not stuck and coolant can pass through the throttle circuit.

[cantfindausername]

Hi Steve, its the normal 3SGTE engine in my MR2, but I'm using a Mustang 75mm Throttle Body. The TB is closed fully, Monitoring is reading 0.0 degrees on the TPS at idle, and there is no Idle control valve.

I'm hoping that it is the flywheel thats caused it and that its going to simply be a case of lowering the idle speed when its remapped.