[ChrisN]

Well it's taken me seven years since I first acquired the Sierra but I finally have the engine running. Most of jobs are done and I only have to get a new exhaust fitted before I can take it along for a registration inspection.

Formally dressed for the rego inspection:


I have a question about idle speed. Starting from cold the engine starts easily but the engine speed climbs to 2500rpm which strikes me as a bit quick for warming a cold engine. Once the engine is warm it settles down and idles nicely. By squeezing the hose that connects the air intake duct to the air valve / ISC pipe I can bring the speed down, so I've put irrigation-type screw valve into the hose and reduced the air flow. That seems to work but can anyone tell me what's likely to be causing this and the right way to fix it? Check Engine light shows no faults. Thanks.



Cheers!

Chris

[JrZook]

My guess it that the idle control valve is probably full of gunk and requires cleaning. I believe that it is controlled by a waxstat and the coolant running through it.

[clanger]

you can try bleeding air out of the coolant hoses to and from the cold start idle valve, but i ended up fitting a blanking gasket under the valve and adjusted the idle with the idle screw which is just near your irrigation valve. now idles nice about 1000rpm

[ChrisN]

Thanks JrZook and Clanger - sounds like the air valve is the problem. If cleaning it doesn't help then blanking it off will stop it being a problem!