I put a new 97 LT1 crate motor in my 93. Had a new chip burned for me by Alvin. But the car still idles at 1500 rpm. I checked my vacuum at idle (so to speak) and it fluctuated from 18-19 lbs. The car has the 94 up intake with no emissions equipment. This motor was complete from chevrolet and I didn't have to change anything except for a couple of the sensors. The car runs great and I have all the bugs worked out except this one. I have already tried replacing the TPS, MAP and IAC with no luck at all on this problem. The idle screw is set back as far as possible without throwing a low TPS voltage code. The only thing I changed on the new motor was the throttle body because I need the transmission cable hookup, and I blocked off the Air and EGR ports with aluminum plates. Is this a vacuum leak possibly? Any help is greatly appreciated.

NOTE : Although this was a new motor it had sat on a shelf for a long time.....

 

93's have a different TPS sensor than 95+ OBD1 and II cars. The voltage readings at idle may be different.....you may need to get one for a 1997 car.

Tony Shepherd

 

If possible. scan to see what the IAC counts are. I would suspect vacuum leak.

 

Still running on a 93 computer and sensors no change there from the old motor. I guess it is time to buy a diagnostic cable for it, I have one for obd 2 but not one for this car . This thing has become mind racking.