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View Full Version : idle speed oscillation... time for a clean


Mike B
02-10-07, 10:06
Hello everyone,

I'm in need of education again!

I use an FconV alongside the stock ECU.

I'm under the impression (will have to heck with El Tel) that the Fcon takes over the engine functions when over certain revs, but when idling the car still runs on the stock closed loop system. I could be wrong on this mind you!

The car has started idling at around 1100 rpm when fully warm sometimes... after a good run she's back down to the normal idle of around 500rpm, but lately she will jump up to 1100, and after a little blast drop back down to 500 again. Cold start is perfect.. no other symtopms.

I'm just wondering if there are any vaccum hoses responsible for the closed loop system or anything that can get gunked over time? If anyone has some schematics or can point me in the direction of some usual suspects to clean and inspect it would be much appreciated.

seems like a possible intermittant gunk problem... and it wouldn't hurt to have a clean out.

b'have
02-10-07, 10:38
It will likely be your idle control valve sticking. Mine did it last week, cleaned and lubed it. fine now.

dandan
02-10-07, 15:35
I don't the vvti's have one Charlie - all done by the one single throttle....

Mike B
02-10-07, 16:12
I have a sneaky feeling i know what it is, will report back when I have tested.

edit - i was right.. fuel pressure was too high.. everything back to where it should be :)