I have a 97 Blazer that I did a complete tune up on including cleaning of the throttle body. After the tune up, I started the engine and it was revving at about 1200-1500 rpm even after it had warmed up. The check engine light came on. I disconnected the battery to clear the code and hopefully reset the idling speed, but don't know for sure if this is even possible without a scan tool. I checked for vaccum leaks and didn't find any. I cleaned and swapped out the idle speed motor with a good one and I still have the same problem with high idle and check engine light. Anyone know how I can correct this? thanks

 

Only thing I can suggest is have AutoZone or someone else check it with an OBDII scan tool and see what comes back.

 

Ditto...go see a machanic and get him to hook it up to a scanner...I'm not a big fan of the "trial and error" method of fixing problems. I've watched my girlfriedn dump hundreds into her Jeep because she was too stubborn to just go hook it up to the scanner...

 

Buy an OBDII code scanner. It's cheaper than replacing parts in a guessing game!

 

why buy one when auto zone will scan it for free

 

I have been having the same problem in my 97 Blazer and after it heats up good and if I come to a complete stop and take off it is shifting hard from 1st to 2nd gear. I am taking it to a transmission shop today after work I will let you know what he says. Or do anybody suggest something different

 

Thanks ya I guess the next step is just take it in and get it checked out but time and $ can make that hard to get to lol

 

Have you driven the truck since the tune up?

Drive it down to autozone and get teh codes pulled, post em up and we'll see what we can on it!!!

 

Autozone said the codes from the scanner read "high idle speed" lol that is all it read so I dont know what it could be

 

My Haynes manual for 82-93's lists the following as potential cases of "Excesively High Idle".
1) Sticking throttle linkage.
2) Choke opened excessively at idle.
3) Idle speed incorrectly adjusted.
4) Valve clearances incorrectly adjusted.
5) Vacuum leakes.

It is possible that while cleaning it, you got some gunk stuck someplace it shouldn't be. Have you tried running Sea-Foam through it yet? Read the directions on the bottle. Do the intake cleaning and put a whole botle in your gas tank.