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[Webby the Bear]

hi guys, hows it going?

i took miggy to have a service 2 weeks ago and my mot is due now.....

on the service they noted an uneven tickover but sait was not a problem and they'll recheck it at my next service...

but this is bugging me now. its auto and when you are sitting at lights the revs are jumping (with no input from me) between 1000 and 1500 rpm.

is this a big problem and easily rectifiable and also will it pass the mot like this???

thanks guys

[amba]

Give the ICV..idle control valve..a good clean first.Metal cannister mounted on the N/Side of plenum,it has an electrical plug at the back and a hose on the front.

Check out the maintenance guide for full details but if that is blocked or slider is sticking due to gunge that will be the probable problem.

[Entwood]

If the ICV attempt above doesn't fix it...

Check for a vacuum leak ... with the engine runing spray around lightly with carb cleaner... when the engine note changes you have found the vac leak - the carb cleaner has been sucked in and burnt as extra fuel - fix the leak, wipe the engine down with paper towel.... result .. fixed leak and a nice clean engine 

It "might" fail an MOT depending on how the leak is affecting the emissions.

[Marks DTM Calib]

Had a similar issue with Tonys car at the Newent meet.

A vac leak was found and fixed and then the throttle butterflies set up correctly and all was good again

[Malcolm_D]

Oooh just like mine! All advice points towards an air leak on the vacuum side, is the increase in revs at idle quite rythmic? Darth Loo Knee showed me that if you squeeze the large air hose going to the ICV so that no air can pass the engine should stall, if it doesn't you have a leak somewhere. The tough bit is finding it, it can be v. small. 

[Tony H]

Had a similar issue with Tonys car at the Newent meet.

A vac leak was found and fixed and then the throttle butterflies set up correctly and all was good again

True, as said pinch the hose to the ICV and see what happens, also check the butterflys are closing properly Mark noticed a gap in mine then set them up. I don't know how they became wrongly adjusted cos when I bought the car the idle sat rock solid at 500rpm and I have not disturbed the settings since. All is well now

[Webby the Bear]

thanks guys, sounds pretty straigt forward. i gotta be honest i dont know anything about engines but good to knw that if they try and rip me off i should know its only a small proob

[Malcolm_D]

Take care, if they cannot find the leak they might just keep looking or start trying others things. At mega bucks per hour it could get expensive, I know to my cost!