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Fast Idle when cold

Posted: Tue Nov 10, 2009 9:53 pm
by Peter707R
Hi,

I have a 1.2 16v which has developed a problem since I cleaned the throttle valve assembly which was caked in black gink from the oil breather. Now, when started from cold, the "idle" speed rises to 2,500 rpm then cycles back to 2,000 rpm and back again over a period of once every 2 seconds for about 15 seconds then it gradually slows down to near 1,500 rpm and reduces slowly as the engine warms. Final idle ends up at just over 1,000 rpm.

The Idle Control Valve is the cause of the "problem" as it can be seen moving in and out changing the engine speed. I have tried disconnecting the battery for over 12 hours and then letting it warm up for 5 minutes before driving to reset the ECU but the problem persists. When warm the car starts without a problem and doesn't "Pulse" so there is definitely a linkage with the engine temperature (the guage does appear to read low at just on 90 degrees when fully warmed up).

Any guidance would be appreciated - I removed the ICV but didn't take off the rubber boot as it appeared reasonably clean.

Thanks

No doubt linked i

Re: Fast Idle when cold

Posted: Sat Dec 12, 2009 11:16 pm
by Peter707R
Well for anyone that's interested, a new ICV didn't help, neither did replacing the temperature sender, so I took it to a local garage to hook up to their diagnostics - no faults of note but the EGR was running just above 1 Volt, which is apparently above what it should be, so I replaced it (£150 - ouch!!!).

Well problem persisted so I went for an Op-Com diagnostic item to try to understand what's going on! The idle showed as being higher than it was set to be but the ICV was working and everything else appeared fine (anyone know where there's a copy of the correct values?). So I took the old ICV apart and cleaned the connections - no immediate change.

So I set about trying to reset as many parameters as possible ("sh*t or bust"!) - well something must have hit the right nerve as the tickover has dropped to 900! Tomorrow will be a test though - a cold start - fingers crossed.

I'm not sure if this experience will help anyone but, if I can figure anything more, I'll update this post.

p.s the EGR is now running at 0.87 Volts at idle.

Re: Fast Idle when cold

Posted: Sat Dec 12, 2009 11:58 pm
by LesterPiglet1
Good luck with that.

Re: Fast Idle when cold

Posted: Sun Dec 13, 2009 12:41 am
by matty101
had the same problem mate cleaned the carb and it went mad, changed the idle control valve, didnt help. changed the mass air flow meter, didnt help. next up i've got a new egr valve to put on see if that helps.


keep us updated mate, wud really help

Re: Fast Idle when cold

Posted: Sun Dec 13, 2009 10:59 pm
by Peter707R
Well it's started twice now from cold - at a 1300 rpm idle dropped down to 1100 ish after a few seconds, no "surging"!

The temperature has dropped now outside which will "test" how well things really are - fingers crossed it looks as if the "purging" of the various parameters via to Op Com has done the trick. Sorry not much help if you don't have one but they're on E.Bay for little more that an hour at the local garage. If you have the Orange light on the dash it should give you the error code (the "paper clip" approach doesn't work on the X12XE -1.2 DOHC engine) although the other functions have to be guessed at as there is no manual provided.

Good luck.

Re: Fast Idle when cold

Posted: Mon Dec 14, 2009 11:00 pm
by Peter707R
Day 2 - car started fine (with temperature just above freezing) - drives smoothly and no "pulsing". I can only suppose that the X12XE ECU doesn't forget what it learns over time by simply disconnecting the battery for an hour (or more).

I hope this helps.