Following a sticking throttle body - I completely removed the standard throttle body from the car, generally gave it a clean up, squirted some spray grease around the throttle return springs then put it back together. Since I have done this, I am experiencing some strange engine characteristics. If I have been accelerating, then come off the power (i.e. to change gear, or to dip the clutch) the revs seem to hold at their previous position for about 1/2 second before dropping back down. E.g. if I accelerate upto 3000rpm, then come off the throttle and dip the clutch, the revs stay at 3000 for 1/2 sec before dropping off. Also, when the revs are returning towards idle speed, sometimes they hover at around 1500rpm for 2 to 3 seconds before dropping down to 800rpm - but the throttle isn’t sticking any more.I wonder if I have somehow damaged the Throttle positioning sensor? Any ideas? Anything I can check that would cause this problem?Thanks in advance…
I don’t know if this is of any use, but those sound like the symptoms of a sticky IAC (Idle Air Control) valve. Another common Elise problem.
Why do you say the throttle isn’t sticking anymore? It doesn’t need to be sticking much for exactly the symptoms you describe.Presumably the above is recreatable when stationary - what happens if you persuade a helper-type-person to manually push the throttle closed when you lift off the pedal?
Sorry - maybe I should have explained a little more. I can recreate the problem by standing at the back of the car and manually operating the throttle; so I know the throttle isn’t getting stuck because I physically return it to the idle position.Im interested to know a little more about this Idle Air Control valve; where / what is it, is it possible to tell if it is stuck without removal of the throttle body (again)Cheers - Steve
Ok - for anyone that is interested or cares, it appears that I have got to the bottom of my throttle problems. When I removed the throttle body, I obviously had to remove the throttle cable. When it all went back together again, I thought I had set up the throttle cable correctly so that I had full throttle and closed on idle however I discovered last night that the throttle cable tension was SOMETIMES preventing the valve from shutting completely. I am literally talking about 1mm or so - but it was enough to feed the engine with enough air/fuel to produce erratic engine RPM. Needless to say, re-adjusting the throttle cable tension has so far fixed the problem. WHOOPS!! [image]http://www.exiges.com/ubb/NonCGI/images/icons/blush.gif[/image]
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