HELP -- replaced fan clutch now idle revs 1200-2000

[dustyroads]

Just replaced my fan clutch (or fluid coupling) and alternator belt. When I started the engine the RPMs registered 2000 and then after about 5-7 seconds dropped to 1200. Then after another 5-7 seconds, the engine again jumped to 2000. Kept the engine running about 45 seconds and the engine would constantly rev from 1200 to 2000 RPM and then back to 1200 and then back to 2000.

I took the alternator belt off and ran the engine for about 30 seconds to see if I had been sold a bad fan clutch, but the same thing happened. I checked all the vacuum hoses I could see to see if one had slipped off, but found nothing out of the ordinary.

Any ideas?

 

[mrnickleye]

You may have knocked an electrical connector off, or damaged a wire. Look very closely at all the connectors, especially around the AFM, and the thermostat housing.

 

[dustyroads]

fixed it. bought an idle control sensor valve off of ebay, slapped in on and all my troubles went away.

 

[mrnickleye]

fixed it. bought an idle control sensor valve off of ebay, slapped in on and all my troubles went away.

Now let this be a lesson for every one !! The fan clutch is obviously NOT related to the ISC in any way, yet his problem started after he replaced the clutch. Gremlins will get in your car and F$% with it, and your head. :evil2: