For some time now my engine rpm has been hunting. The first thought was that the ISV is bad. This weekend I tried flushing the ISV using carb cleaner for the 5th time. The last time I cleaned the unit it seemed to help a little.

I put the unit back in the car this afternoon and to my horror the rpm hunting problem is worse! I read some were else on the internet that if I put 12v across the leads on the ISV, the unit should rotate. I tried this and nothing happens. Is this an indication that the unit is screwed and no amount of cleaning will help?

Over the past few months I have been searching the local auto wreckers for a replacement ISV but have not found any ISV the same as mine. There is no part number on my unit. It has two vacuum hoses and two wires from it. Is it possible to use a different ISV than the one I have?

Getting desperate here! May have to break down and buy a brand new one from the dealer!

Thanks

Jamie

89' 2.3l engine

The ISV on my '89 200QT is controlled by a control unit located under the kick panel to the left of the clutch pedal. The resistance across the ISV terminals was 4ohms; normal. There was no current coming from the control unit; not normal. To check that, put a ammeter inline with one of the wires that connect to the ISV and use a jumper fo the other one. It should read about 450mA. For good diagrams and great info, go to AllData.com. For about $25, you can get a whole manuals worth of information thats printable. It often beats using the Bentley manuals. When I get a replacement control unit installed, I let you know what happens.