I've got a '90 Formula I converted to TPI a couple of years ago. I've been looking to replace the harness with one in better condition and since GM no longer offers the auto version (can't figure why) I'm left to the aftermarket. I've been looking into the Painless offerings but I'm not sure if it's the way to go for my situation. I'm not concerned with emissions as there's no smog testing here in NC on pre-96 cars, just a visual and most if not all in this area don't know what they're looking at anyways. How difficult would it be to use the Painless TPI harness on my car in regards to tying it in with the other existing electronics? Has anyone here done this type of install before? I've seen where individuals used it in stand alone for cars that were custom setups but that's not what I'm after, can it be used to replace the aging harness and how difficult would it be to integrate it?

 

Did you have a Painless part # in mind?
The only Painless TPI harnesses I have seen have been standalone ones for engine management only designed for retro fitting TPI onto carb cars,
Basically plug the harness into the TPI sensors , connect a couple of hot wires and a fuel pump; done.If using that type you would still have to run / replace the wiring for other systems like A/c and gauges that are present on your car but are not part of the engine control

 

I was looking at #60103 for 90-92 MAP TPI engines and if needed #60314 which is an emissions hookup harness. The car doesn't have a/c so no issue there but I've pretty much come to the conclusion that it wouldn't work without extensive work but figured I'd ask here as a last ditch effort.

 

Painless is most often painless. A few hookups and it runs

Integration means reusing part of you old harness to keep the stock gauges. Luckily, the part you reuse is rarely damaged

Read this
https://www.thirdgen.org/forums/ltx-...p-3rd-gen.html