Need help with 88 turbo supra. When TPS is plugged in the fuel cuts off. But when it is unplugged it runs fine but gets spark knock but does not throw check engine light from being unplugged. Any help would be appreciated.

does your check engine light come on before it completelty shuts off,if so allow the the light to come on ,now the computer can read a trouble code telling you what the problem(s) is.all you need is the obd1 or obd2 code reader to (whichever it is) tell you the code of the misbehaving part(s),this code reader aught to be available at a local parts store.if the check engine light does not come on when the car dies with the tps sensor plugged in,then ,well i'd really have no idea of what the problem is.my last thought is that the tps is not functioning correctly, it may be sending a signal to the computer that is false;telling the computer that there is a very high fuel demand that exceeds the fuel cut limmitations,hence fuel cut off.just a theory.anyhow i hope this helps,laters!

TPS....hmm...why would that cause anything really, the only thing I can think of is that it's sending a signal that the throttle isn't opening. You can ohm the sensor out and get the readings from it to check if it's good.

You don't need a scanner, you can jump the pins on the service plug, and the check engine light will blink telling you the codes...

This sounds like a nasty gremlin, try checking the TPS with a multimeter and get it ohmed out, if it's fine, about the only thing I can think of is the ECU :(

Checked the codes with the jumper wire, i get code 41 which is throttle position sensor voltage. I replaced the sensor and still get the same code and running conditions.

Got it fixed i removed the TPS again and realized that i when i replaced it i put it back on wrong. My stupity. Thanks for the help.

at least some problems get fixed around here, eh?

Don't feel bad I did the exact same thing. Except my original one was good and I stuck it on wrong and ended up buying a new one. But I figured it out and brought the new one back.