I went to reset my TPS to fix my annoying idle problems and found there was no ISC on my car - at least where it should be. There is the 6-pin connector by the coils, but no 2-pin ISC present.

There is a 2-pin green connector that could conceivably be a relocated ISC close to the solenoid rack, but i don't want to go jumpering random plugs in case i blow something.

The car is a 1986 Series 4 Turbo (That would translate to an '87 T2 in US terms).

I don't exactly know the full history of this car, and being a japanese import it may be that the wiring harnesses were slightly different to the US models - or that some previous owner has messed with the harnesses. It is also an auto-to-manual conversion.

Is it possible to jumper the ISC at the ECU?, and if so what pins should I jumper and/or connect to ground. Ideally I would simply run new wires from the ECU to a switch or jumper to make this easier in future.

I have consulted the FSM but it has a pretty poor ECU pinout section, and the wiring diagram doesn't seem to detail the exact pins that the ISC connects to - I could be reading it wrong, but I was wondering if anyone knew for sure which pins i should use.

Thanks

-Pete

 

Pin 1J as shown in the fsm under Control Unit and also in the wiring diagrams.

It could care less if it gets grounded at the ECU or the front of the car.

 

Jumpering the ISC or not jumpering the ISC will have no effect on whether you set the tps right or not. Never has, never will. A properly set series four tps will output approx one volt to the ECU when set properly. See CONTROL UNIT in the FSM. It's pin 2G, a red/green wire at the tps and the ECU.