Where do the gauges get the tachometer reading from off the coil? Is it the solid pink wire?

 

Not really sure, but most newer cars actually get the tach reading directly from the ECU. If your installing a add-on tach. I would go to the coil.

 

Im doing a swap, I got a lt1 in my 91 camaro and im going straight to the coil, I put it on the connector with a color wire, pink/black wire, and solid pink, I spliced it into the solid pink.

 

The solid pink is 12v. The pink/black should give you your tach signals.

 

Thanks a bunch shoe box, worked like a charm! I got power when i turn the key now. Now I dont think the ecm is getting power because I dont hear my fuel pump priming and I cant connect to it using the ALDL cable that wired straight from the aldl to D30 (Seriald data) on the blue connector and the ground from the ALDL to D1 on the blue connector, straight through and it cant see it.

I had a question for you shoebox, how is the computer getting its power? Do I need to run a power cable from the battery or power distribution to give it power? Or does it pick it up from somewhere else? Im using my thirdgen ALDL cable, I think I can use it with the fourth gen PCM. I dont think its the cable, I just dont think the PCM is getting power, anyway to check if it is? Thanks guys.

 

Anyone care to give it a shot? .

 

Look through my PCM pinouts info.

PCM battery feed is constant battery.

PCM ignition feed is battery when the key is ON.

 

yea found those a bit ago, but I still got no power on the ECM, does vats not allow the computer to be on or is there any way to test the computer is turning on when the key is turned? I cant figure out why I got no fuel pump prime and why I cant program the PCM. I got both 15 and 31 going to power and I got the pink wire from the coil I havn't touched going to the pcm.

 

Basically what im looking for is how do I get those two ignition power sources on the pcm from the thirdgen wiring harness? Are those 2 ignition sources on the PCM tied into the coil ignition wires? Those are the only ones I havn't hooked up and can see that as being the only reason my PCM is not coming on.

 

Nevermind, i gave it power to the pink wire and the computer came on, I can now read it through tuner cat . Thanks a bunch guys!

 

Just programmed it, woo hoo, im gonna put some fresh fluids in and start it tomorrow, wish me luck .