Help! RPM'S high after warm up

[Ty Love]

I am the proud owner of a 1986 Corvette!! I was driving it to work and found a coolant leak coming from the oil cooler hoses so I changed them both. After that, I put a new thermostat (195 OE) in it and changed the throttle body gasket and now when I warm it up, the RPM'S go up to 1200-1300!!! I did a check to see if I had a leak around the throttle body gasket area but didn't find one. I also changed the O2 Sensor to and now when I start it up, it runs rough and dies out!! All of this happened after I put on a few parts!!! I have wanted a Vett all of my life and now I have one to drive. I don't want it to sit, need help!!!

 

[hcbph]

I can't be sure but I can tell you what I experienced on my 86. I was getting random DTC41's (IIRC) at around the 165 degree transition of the engine (SES light came on and ran like crap), I believe when the engine goes from closed to open loop is when it happens. The error indicated that the ECM lost contact with the engine. I had problems with that error message as it seemed consistent and ran great otherwise and didn't happen other times. Well one day I was digging again into it and unplugged and replugged the connectors on the TPS and IAC valve plus I gave the IAC Valve a couple of taps with a plastic faced hammer. Since doing that I have not had it reoccur and have not had any other driveability issues with the car. Being you did mess with the throttlebody and that's where mine seemed to have originated from, that's where I'd start looking first.

Myself, I plan to replace the IAC valve over winter if I get the guts up to take the Maff off to get to it.

Good luck.

 

[Snapper]

The idle position sensor under the throttle body has dirt in between the cone where it seats with the throttle body base. Remove sensor, clean cone area with throttle body cleaner and it carb cleaner. Also spray inside the area where it seats and out back together. There is a small gasket that has to be replaced as well before screwing it together. Should take care of your rough idle and high idle issue...

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[Ty Love]

I got it fixed!!

Hey guys thanks for the help!! I have that problem worked out!! After cleaning out the throttle body of all of the build up, it changed the setting. My guess it that it was adjusted in that condition. I just set the IAC motor to its lowest settings, disconnected the timing and warmed up the engine and checked the base idle. Guess what I found? It was out!! I set it to the proper setting and then disconnected the battery to reset the ECM. Bamm!! Done!!