Hunting idle

Supermarine Blues · Post by **Supermarine Blues** » Sun Apr 07, 2013 7:41 pm

The alternator's probably hot & whining (like a good woman) because it's working hard to restore a flat battery & supply the electrical load to the car. Mine did too when the battery was nearly dead.

jake · Post by **jake** » Mon Apr 08, 2013 5:09 pm

Mine started hunting just prior to the aircon pump seizing up - I assume it was putting more drag on the belt and hence on the engine resulting in a dip in rpm that the engine then tried to compensate for.

I'm currently running with an aircon remove belt and it's all happy, but the other thing I read was that the ECU cuts fuel to the injectors if the throttle is fully closed and the engine speed is above 1150 rpm (it thinks you're decelerating using engine braking).

If this is the case that explains a lot of the hunting / bouncing revs - something causes the engine to speed up (duff component, whatever), revs go over 1150, engine cuts fuel, revs fall, ecu restarts injectors and repeat. By juggling the throttle I could stop it bouncing but it always restarted when I came to rest.

Got this info from here : http://ecomodder.com/forum/showthread.p ... d-967.html and sounds plausible.

Either way they're a pain to sort! I did all the IACV, FITV stuff first before the pump seized and it all made sense!

Jake

Riverghost · Post by **Riverghost** » Thu Apr 11, 2013 9:09 am

Nice thread and vids, will have to hunt out that guys cooling vid

Zoe · Post by **Zoe** » Sat Jun 07, 2014 3:27 pm

I have a 1999 Honda PreLude SH. My PreLude's idle is never constant. Whenever I turn it on, the idle is high and low, never constant. I recently got the block bored and honed out, I put bigger pistons in it, 20 over. I know I'm going to have higher compression. We have tried a valve adjustment setting them to O.E. specs, same thing happens, never a constant, just high and low. Someone help me out, what should the valve clearances be with 20 over pistons?