Any ideas why all of a sudden the idel incresed to 1500rpm instead of 700?? This is a '95 discovery with the 3.9. This must be my fourth post and I have had my landy for just over a month!!

 

Is it a continous 1500 idle or does it go back and forth? It could be your Idle Air Control valve (stepper motor). It should just need a cleaning and if it is bad I head a 5.0 litre Chev motor for the same era used the same IAC. Hope it helps.

 

it stays steady. where is the idle air control at?? How do I clean it?? Thanks!

 

I am not sure about the 3.9 but on the 4.0 it is along the air intake after the mass air flow sensor and just before the throttle control. I know that on the 3.9 it is a screw in type and it should have a couple wires plugging into it. It you do not find it tell me again and I can look it up in the manual. I just dont have it with me right now. Clean it will with some carb cleaner and where it goes into. Hope this helps. Also try this - when it is idling well, just disconnect it again while the engine is running. The check engine light will come on but if the problem does not repeat itself then you know what the problem is.

 

Well I cleaned it, boy did it need it!! I also sprayed some cleaner in the hole. I started it up with no luck! I did unhook it, even though it was still at 1500rps and it went up to 3000rpms!! Any ideas?? also do you know where this vac line goes? It might have something to with it! I posted this before but with no pic. It is on the rear of the drivers side valve cover. It is over a foot long.

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I will look it up for you. You might want to get the disc repair manual for your rover. Its very cheap on ebay.