(Car info-1992, Z28, 305 TPI) So my car Idles at about 1100 RPM and I know that seems high but it doesn't sound like its running at a high idle. I had a vacuum leak so i was assuming that was causing it. Fixed the leak and no change.(unplugged the battery for more than an hour to reset the ECM) Well I finally got my OTC Genesis back from the Matco guy, and hooked it up. The in car Tach reads about 1100, but the computer reads 700. Any Thoughts? Common? And is there a rev limiter on this car. It does have a hypertech chip. P.S I got the chip with the car but it was not installed and after installing the chip the idle still remained 1100.

 

It is the tach. See the sticky's on the Electronics board here on TGO. Full instructions for how to fix it (rather easy).

In stock calibrations the rev-limiter is usually set to something over 9,000 RPM. Basically it is disabled.

RBob.