I have a 97 Discovery. It has a newer engine with 40k and 158000 on the body. I purchased the truck last week. The truck needs work but overall is in good shape. My biggest concern is the high idle. If its in park or neutral it revs to 2500 plus. While in drive or reverse it idles at 900-1000 which still seems a little high. Any ideas on what I should look for or try? There is a mechanic near by who specializes in Land Rovers, but I'd rather not spend the money if I don't have too.

 

Do a search in the forum. This has been gone over alot. Start with downloading the RAVE and checking vacuum lines.

 

the RAVE?

 

Check my signature. It is the Factory Service Manual.

 

Thanks.

 

Idle Air Control Valve. Its in the intake, around/just under the throttle body. Pull it, clean it BUT dont move the plunger. Put it back in. If it does not help, check for vacuum leaks. If no go there, get a new IACV.

 

Always test the component before you replace it. There are other components that can cause a high idle besides the IACV.

 

I'll give it a shot. Is there anything specific i should try and clean it with?

 

Intake/throttle body cleaner. Do not use carb cleaner. They are not the same.

 

I have too much experience with this..

Its either....

IACV
TPS
or...
ECU..

You can rule out the TPS with a scangauge or something that can show you live data. If you dont have anything to show you this. you can check the ohms with it in different positions. However I totally forgot the value.

I think there are two different types of IACVs I know for a fact you can not worry about moving the pluger itll be fine..

Try cleaning it, but if its dirty it would restrict flow and computer would tell it to open up. But if it was stuck computer cant open it up and it would MOST LIKELY give you a fault.

It should close at every shut off.

And finally, I had a bad ecu... If you get a new ecu make sure you get the matching security ecu with it.

The TPS is 90$ at autozone
The IACV is 45$ at advanced
The ecu can be found at junk yards..

A shop can reset the adaptive value for the ECU and it'll probably cost you 90$ but if your ecu is bad it will go back to how it was. Ask me how I know..

look for a thread by me it should have alot of information that I can't remember..