Porsche Enthusiasts Club Forum

Last year I had my 1990 S2 1200 mile serviced and the belts and rollers replaced. I do not use the car very often but since the service I have found the car to tick over unevenly. I wonder whether the belt has been replaced incorrectly. Is this likely or is there more likely to be another cause, the car seems to go ok at higher speeds. How do I check the correctness of the belt instalation? I made the mistake of giving the work to an independent so called porsche specialist and want to be sure of my facts before contacting the garage as I am a bit doubtful of getting them to do anything. If It is a relatively easy job to check and adjust. I would consider doing it myself but am a bit scared of undertaking anything to complicated.

It could be an air leak, the engine will hunt at tickover, have a good snoop about with hoses and vacuum lines.

How often do you use it. They can be a bit lumpy after standing awhile. Mine was pretty bad but after a week of daily use is perfect again! Check for vacuum leaks. Have you replaced the vacuum lines? You can get a kit of silicon hose that looks great for £20 colour coded. Idle control valve another culprit. Clarks garage a good place to start.

I'd go for a sticky idle control valve, you can flush them out with carb cleaner

ISV under the manifold needs a clean out, carb cleaner or an ultrasonic bath are best. Using the car more will pay dividends in the long run,
Alasdair