I'm having problems with my 87 2.0L again. I have been getting an intermittent Service Engine Soon light for Code 22 - TPS low voltage. I'm getting bad fuel mileage and it would occasionally stall under acceleration.
I checked the voltage of the wires at the TPS connector a couple of months ago and it showed normal while moving the throttle. That's something I know I need to double check. I decided to replace the TPS with a brand new Delphi unit and it has made the car worse. Now the SES light is on and I still have the Code 22. There is also a hesitation on initial throttle that was not there before.
Where do I go from here?
did you set it correctly at idle when you installed it? you can't just slap it on, it has to be set to read .45 volts at idle do a serch on here and you will find out how
I have to say the best way to understand this is seriously by a Haynes manual.There is too far much to type to make it well easy.In short you need a multimeter and a Phillips head screw driver that should hold it or bolts(more likely screws) this can moved back or forward to achieve the correct voltage reading for the tps to properly register with the tbi and ecm for good idle,running in general.The # above 0.45 can go up to 1.25 volts for actual adjustments based on book specs.This is not hard just to lengthy to post seriously.Buy the Haynes GM manual 82-94 book #38015 chapter 4 this covers the fuel and yeah TPS! Ebay has these new/used cheap buy one they are available all day on there.
haynes manuals suck, either find a good chiltons or search ebay for a factory service manual, haynes manuals are all over the place for crap.
as I suspected your tps isn't adjustable, if you are getting a low voltage reading its bad, and needs to be replaced, it just bolts on , no adjustment.
That's what I did. I installed a brand new TPS and the problem is now worse than with the old TPS.
you use a generic or ac delco unit
I just swapped din a generic iac and for some reason the idle creeps right on up after a few days of driving
Check voltage at the connector, should be 5 volts. If that's okay trying wiggling the wires all around. Since this is intermittent it's likely a broken or pinched wire.