Needing Help with Throttle Position Switch (TPS) on 1993
 

I screwed up! I took the TPS off when I replaced the injectors. Big mistake. I tried to put it back where I thought it was located. I guess I didn't get it in the right place because I'm getting a fault code for the TPS.

From reading the FSM, I will either need to take it somewhere for repair or buy a Tech I and do it myself. So at this time I'm looking to buy the tool needed to put the TPS back so the system will get the proper voltage.

Is there anyone here that has made this repair and what tools you have used? Any advice would be greatly appreciated!

Thanks...E:cheers:

How to Adjust the TPS to Spec using a Digital Volt Meter
 

I adjusted my TPS with a common digital volt meter (DVM).

You have to have the TPS installed for this adjustment. I believe the proper voltage is around .54 volts. The TPS has (3) wires, but you only need to tap (2) of them, the Blue and the Black (ground).

1) Using a small flat-bladed screwdriver, flip the TPS cover back from over the end where the wires enter the connector body.

2) Using a small pick or fine flat bladed screwdriver, gently pull back the three rubber grommets that surround the wires as they enter the connector body.

3) You need the key in the 'On' position (engine off) to do the adjustment.

4) Connect your volt meter leads, one to the Blue wire, one to the Black (ground)

5) Loosen the 2 bolts like you did already, then slowly twist the sensor either way until the DVM reads the correct voltage.

6) Then tighten the bolts back down without moving the sensor again.

Re: Needing help with TP Switch
 

Thank you that sounds great. I thought I might have to spend another few hundred on a tech I or something. I've got a good volt meter, now If I can find which wires to tap into....:cheers:

Re: Needing help with TP Switch
 

There's no reason to pierce any wires.

The connector for the TPS can be partially disassembled for adjustment purposes.

1) Unplug the connector from the TPS
2) Using a small flat-bladed screwdriver, flip the cover back from over the end where the wires enter the connector body.
3) Using a small pick or fine flat bladed screwdriver, gently pull back the three rubber grommets that surround the wires as they enter the connector body.
Plug the connector back in to the TPS.

You can now use your standard DVM leads to probe the connector, without piercing any insulation. If I remember correctly, it's the top and middle leads that you need to measure across. I think the bottom one is the 5V reference.

I will go check my diagrams to confirm.

Re: Needing help with TP Switch
 

On a 91, and possibly other years, the wire colors are Dark Blue and Black. Black is ground, Dark blue is the voltage the ECM is seeing. The third wire should be the 5V reference signal (Gray, I think).

Re: Needing help with TP Switch
 

Mid America sells the adapter to make this easier or as stated you can get some wires into the plug to get the reading you need.Its possible to get the switch back on the car and dial it in by ear,idle will move around but when I did this I didnt get a code.Did you get the tab in the switch lined up correctly?Ive set mine with the exposed wire method but I do have the adapter from Mid America as well.This was done on a 91.

Re: Needing help with TP Switch
 

Just do the blue wire on the TPS and any good ground.

Basicly take your volt meters Red lead to the blue wire at the TPS the Black lead from your volt meter to any good ground.

Pete

Re: Needing help with TP Switch
 

Good point, no reason to mess with 2 wires on the connector when just the one will do the same thing.

Re: Needing help with TP Switch
 

YOU GUYS HAVE BEEN A GREAT HELP TO ME!...THANK YOU!

:cheers:

Re: Needing help with TP Switch
 

I keep a couple of paper clips and safety pins in the tool box because, if careful, you can slip them under the rubber GM weatherpack wire seal and touch the metal terminal. then use a clip lead to attach the pin to the meter leads...hands free at that point.

Re: Needing help with TP Switch
 

Good call on the no-pierce methods, guys!

I didn't even think of that when I did mine and I usually do think of things like that.

Re: Needing help with TP Switch
 

This is how I did it the first time,takes a little patients but it works.

Re: Needing help with TP Switch
 

Yes; applies to most GM EFI systems.

Re: Needing help with TP Switch
 

Thanks again. are you sure about the .54 volts DC ?

Re: Needing help with TP Switch
 

pretty much for most of the 90's GM stuff. when I had my vacuum leaks, the first thing I checked was the TPS setup and it was factory set at .54 or .55 volts. I would set it to that level- should be right after that.

Re: Needing help with TP Switch
 

I will do that.
Thank you...E

Re: Needing help with TP Switch
 

I got the TPS set back where it should be an it no longer has a falt code for the TPS ! Thanks to all of you for your input.....E