How is yours hooked up on your LT1s, mines a 97 OBDII, i'm having issues with the RPM reading, sent the switch back, & it checked out good, but was tested on an LS1 car & truck, my ignition is stock, the coil only has 2 wires, a green & brown, all the programming dials in, but the RPMs are a good 2000 above what they should read, would i be better off hooking it to the tach signal off the PCM, if so, which wire is it? Chris & Ray have been very helpful, but there alittle stumped too as to why it won't read on my car, so if anyone has any ideas, that would be great.

 

Hook it to the white wire at the ignition control module (the plug in is just above the coil). Thats also terminal #5 at the pcm in the red connector if you want to wire it from there.

 

Thanks, i had it hooked to the green coil wire.

 

Ok if you where off by 2000 rpms @ what rpm was this? The box allows you to change that input from number of cylinders, to individual coils etc. When you connect it back up;
Set you rpm into to what ever number you think it should be. 000 004 008 etc.
Then once done with all programming start the car and increase rpms to 2000 push the #1 buttom. it will show you what rpm the box is seeing. If its wrong change step ones set up numbers to a different count. If you where at 008 then go to 004..
REtest.
This is just one of the features that helps you with figuring out if there is problem.
Once the box matches the tach take it up to 3K to confirm matching there as well...

LS1 cars are set too either
000 if connecting to the coil
004 if connecting to the computers tach wire....

 

This is for a 97 LT1.

 

Just hook it to the wire i mentioned above, and program the box as 008 for a typical 8 cylinder engine with one coil.