Discussion
Check the throttle is closing fully. When it's fast idling, push the throttle link down against the stop. It shouldn't make any difference; if it does then you have a mechanical problem with the throttle linkage. Failing that, you have either an air leak or a stuck stepper motor. There are only a few places where an air leak is likely and basically if you check that all the openings to the plenum have a hose connected and confirm that the revs don't drop when you squash each hose flat then you're pretty well ruled this out.
Mine does exactly this after a hot start.
If I stop the engine, only leave it a couple of minutes then start it again it sits at 2000 revs, then seems to slowly die back down to normal idle speed, though I've usually driven off before that happens.
Once I stop again its fine.
I haven't got to the bottom of it yet, and as I currently have my distributor in bits (vacuum unit gone & the bit it moves inside was seized) I haven't had the chance to pursue it.
I did wonder if it was something like a leaky injector that continued to drip fuel into the manifold once the engine is turned off but I'm guessing here.
Does this sound similar to your problem ?
Chris
If I stop the engine, only leave it a couple of minutes then start it again it sits at 2000 revs, then seems to slowly die back down to normal idle speed, though I've usually driven off before that happens.
Once I stop again its fine.
I haven't got to the bottom of it yet, and as I currently have my distributor in bits (vacuum unit gone & the bit it moves inside was seized) I haven't had the chance to pursue it.
I did wonder if it was something like a leaky injector that continued to drip fuel into the manifold once the engine is turned off but I'm guessing here.
Does this sound similar to your problem ?
Chris
Gassing Station | S Series | Top of Page | What's New | My Stuff