I just bought an old ATC 4000E that came with a grey TPI cable. My car is an 87 305 TPI. From a search I found that sometimes the TPI cable is needed, more times the regular GM OBD I cable is needed. I am getting eratic readings with the tool. Idle RPM at 6260, voltage at 25, injector pulse width 0 ect. I suspect I need the regular cable. Does any body know the pinouts for both cables or if you have the regular cable, list what the pinouts are for both ends? I think I could cut and splice it to make it work. The old cable does not appear to be for sale anymore.

The Gey one is the one you need for TPI .

as for the black cable thats is for Carb,TBI you can use this too but without high speed data.

Sounds like 4000e need's to be Repaired
I have both the 2000 & 4000 and they will do this.

is your Primary coolant fan coming on at wrong temp too.?
(thats is if you have)

I *think* the TPI cable is only needed for the 165 ECM's in TPI applications, not sure about 730 TPI. I can take a look tomorrow at work, as we have a 4000e and a genisys. Pretty much any other 82-95ish application uses the black, standard adapter, even for high speed ALDL. Example, every application that has a 730 that I've scanned (haven't scanned a 730 TPI lately) uses the black cable, along with the 4 cyl TBI 165. I have to use the scan tool on for sure tomorrow anyway, so I'll plug a couple applications into it to see.