My car is running, but I keep getting code 22 (low TPS voltage), which apparently is causing the car to surge at idle. I read the article here and am confused. I can't make sense of it, I don't understand how I'm supposed to rotate the TPS?!? It doesn't seem like it will rotate. Also, I can't seem to get a reading off of it. Can anyone give me a "TPS adjustment for dummies" lesson? Thanks.

 

Hmmm... I find it hard to believe that none of you gurus know how to adjust the TPS .

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91RS convertible 355 TBI 65# inj. custom compcam grind .480/.480, Edelbrock TBI manifold, open element, hedman hedders, Y-pipe, cheap cherry bomb muffler, Hypertech cop car thermomaster, Accel coil, wires. 2.02/1.6 cast iron heads. Engine specially made by Pflugerville machine shop. Forged bottom end, balanced. Coming soon: Vacuum controlled FPR, better exhaust, Torque converter, DIY PROM, bigger TB.

 

never done it, but.. if it says rotate, you would rotate the throttle shaft wich will rotate the tps for you internally. if you cant get a reading, i would say your tps is bad, but usually a bad tps = car runs really really shi*ty.

 

Bought a new TPS today, and it's different from the one that came on the car! The screw slots are made so that it is possible to rotate the TPS! Go figure! I'm going to put this on and try it out. My car has been running like a F*rd product lately!

 

there are quite a few variations of tps sensors out there that are similar, hopefully the one they gave you operates on the same voltage variances. gm is still redesigning and consolodating part numbers etc. if they have one part that works on 2 cars that originally had 2 part numbers, they will get rid of one. that way they dont have to keep making so many different replacement parts.

 

Put a voltmeter on the a&b terminals and adjust it at idle with the key on to .54 volts give or take .075...Oh and make sure you have 4 volts or more at wide open throttle. My car likes .58 volts

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89 RS 305 TBI/Hooker catback

 

which ones are the a&b terminals?

 

There are three ports on the TPS...wire colors may vary from vehicle to vehicle...mine are BLK, BLU, and GRY. To do this the right way, you almost have to make a jumper that will go between the harness Weatherpak for the TPS and the TPS itself.
Install the jumper wires between the vehicle wiring harness and the TPS....with ignition power switched OFF. Switch the ignition power to ON, but don't actually start the car. With a digital multimeter find the two wires that give a voltage reading of about 0.54VDC...some vehicles call for a reading of 0.64VDC. Loosen the TPS just enough that it will move ever so slightly...this part takes a very steady hand. Adjust the TPS to a reading that matches the spec by +/- about .02VDC (that's what the specs are as far as I know) and tighten the TPS back down. Recheck the voltage on the jumper wires and turn the ignition power off. Remove the jumper and reconnect the TPS...go have a beer...done.
EDIT:
I wanted to give a little clarification on this since it is something I am actually confident in knowing how to do.
The BLK wire from the TPS is the GND. The other wires are the actual signal and reference wires. The reference wire (GRY) should read +5VDC. The DK BLU wire is the TPS Signal wire and it should be the one that varies with throttle position sensor movement.
To make the jumper (as I am sure many of you have figured out) all you need is a couple of new 3-tower Weatherpak connectors...one male and one female. Wire the two together making sure to match ABC terminals between the two. Splice a small length of wire in the BLK and DK BLU wires. This will help you get an accurate voltage reading while adjusting the TPS and it will prevent you from needing 4 hands at once to hold multimeter connectors to the wires and adjust the TPS to the right voltage. Use alligator clips to hold the meter leads to the jumper wires. Adjust the TPS signal with the key in ON but the engine NOT RUNNING. The idle voltage may be different for your particular application. I think yours will use the 0.54VDC spec +/-0.02VDC. The spec I stated above (0.64VDC+/-0.02) is for the Holley ProJection system and I suspect it would be the same for a TBI 2.8L engine in something like an S-10 or S-15 pickup.
and happy

 

A=BLK wire (NEG meter lead here)
B=DK BLU wire (POS meter lead here)

 

The TPS sensor on my 91 is not adjustable at all

 

Going out on a limb here...it is probably because the TPS on your TB is an OEM TPS. An after-market TPS (replacement) would probably be adjustable. You can adjust the OEM TPS if you want to fool with the throttle shaft...but to me that is a real PITA.
If someone has better info, please post it as this is the best I can do.

 

my 89 rs tbi is doing the same thing. i bought the new adjustable tps and it still does the same problems and gives same code even after i clear it. i think my harness connector has a short?

 

any updates ? i have a code

Code 22: Throttle position sensor voltage low

i think my TPS is going to?

http://www.napaonline.com/MasterPage...on+Sensor+(TPS)

 

if yours is adjustable you can correct it. but when you do, you need to unplug some sort of red wire typically found on your passenger side of your engine bay. it should have a fusible link that can easily be unplugged. that way your computer wont try to over correct the throttle/idle when you make the adjustment. tps have been known to go out. also check your wiring. sometimes the wires to the tps have been bent back and forth a lot messing with the connection.

 

thanks for the help
no my TPS unit is not but i will check to if there is a wiring problem

what does an adjustable TPS look like so i can get it