2006 LS Focus 3000 revs cold start 2500 hot

Loco · 30-01-2011, 01:06 AM

Hi, I have LS zetec with 66,000 Ks. For the last two weeks It has started to rev to 3000+-200 off a cold start and 2500+-200 off a hot start and only lasting for a second or two.there are no obvious vacumm leaks and the throttle body inside is clean.I have held the throttle plate fully closed while starting and it still over revs.The(2 electric? vacumm solenoids?choke control?) mounted near top of engine have been replaced with new(service centre thought would fix it ) and it is still the same.Is there an IAC valve I should be looking at on this engine? There are no DTCs I am getting worried this is gonna cost me more and more on the chase down.I have looked all over net ,nothing applicable.If anybody knows the answer I would be truly grateful .Regards Loco

Loco · 01-02-2011, 12:38 AM

Hi again, more mystery now or maybe another clue. Car has spluttered and cut out twice. One day middle of roundabout next day going up a hill ,both times dash display showed -engine system fault.Car started up fine after pulling over except for original startup problem. The engine system fault message disappeared and again no DTCs were found.Car then ran O.K. Still hopefully seeking answer if anyone can help .Forgot to mention before car is auto.Regards +thanks Loco.

In Focus · 01-02-2011, 12:41 AM

If you've eliminated mechanical causes, maybe it's ECU related?

Loco · 01-02-2011, 10:59 PM

Thanks for the suggestion In Focus appreciate it! You could well be right as the engine symbol light as now just come on while driving home, no detrimental effect on performance, did not cut out this time and once again unable to bring up any DTCs with trip reset trick ,10 mins later parking and restarting symbol has disappeared.I am starting to think I may have to bite the bullet and take it to local ford dealer see what they say for starters at least.This is getting weird different symptom every day.Cheers Loco

Loco · 10-02-2011, 07:50 PM

To anyone who may be interested, problem solved and fixed. It was a split hose beneath the inlet manifold.Many thanks to Macarthur Ford Service department for a quick outcome at a reasonable price including a reprogram. Regards Loco.

20focus05 · 12-02-2011, 11:00 PM

Was going to suggest that vacuum hose have heard of it causing this issues before.

Loco · 14-02-2011, 11:32 PM

Yep , vacuum leak was my first suspect too, but somehow I missed the hose beneath the inlet manifold.From what I am told it is hard to get to and not that easy to change as starter motor needs removal for access.All good now. Regards Loco