I have a 99 Si with a GSR swap. My issue is that the car will not shut off when I use the OBD1 ECUs (P28, P72) with conversion harness, but as soon as I plug the stock Si ECU OBD2 (P2T) it shuts off just normally. I have used a few ECUs and have exchanged the conversion harness also and still does the same, only shuts off with the P2T. So, of course I want to use the OBD1 ECUs but cant figure out how to make the car shut off besides stalling it.... Could someone please give me some insight on what to check or do so I can use the OBD1 ECUs and be able to turn off the engine? Thanks

 

Try a different obd1 ecu (i know you've done this a fiew times but still). like a known good virgin p72 maybe a different jumper harness also

 

Thanks for the reply. I have tried that already, good virgin P72 and a couple of different harness but still the same result. Only the P2T shuts it off...

 

A good way to shut off your car if it doesn't wanna cut out is to unplug the alternator and disconnect the battery, in that order. It should die pretty quick. Or if you wanna be rowdy, just drop the clutch while in gear and let it stall out.

 

Bump!
I am still having the same problem, is there anyone here that has any other ideas and/or any input on this? Thanks

 

Maybe a bad ignition switch.

 

Thanks, I'll try the ignition switch and see if it works.

 

So I changed the ignition switch with a new one hoping that it would fix the issue but had no luck, still doing the same thing (Only turns off with the P2T)... I would just leave the stock P2T but you can tell the engine doesnt run right. I would be good with a virgin P72 but I have tried a couple of them (OBD1 and 2) and still the car wont shut off... I know how to turn it off but of course I want it fixed. If anyone knows what else to check please let me know.