Does anyone know what the voltage output range is supposed to be on a 82 TBI Throttle position sensor?
I have a GM Shop manual but cannot find the out put of the TPS in it anywhere. I have a scanner and can read the voltage, but it seems to be very low with a very low range right now. I am troubleshooting a performance problem that just recently started, and I got a code 22 and code 33. I have a confirmed good MAP sensor so I installed it. No change in the poor running condition. So, I was trying to follow up on the code 22 by checking the range and reading of the TPS.

Or, if you think I am on the wrong track, I am open with all ears.

 

.525 + or - .075 volts. Measured between the bottom and the center connectors. Code 22 is the TPS and 33 is the MAP. Page 6E-60 in the shop manual.
Good Luck.
Steve

 

Correct. But as I understand the .525 setting that is for idle setting. My scanner will monitor the TPS as I sit in the car are rev it up and down. I can watch the sensor reading and it does not move very much, plus it does not start off at .525, it is lower than that to start.
Would the TPS make the car run rough, mean really rough? It is so rough, I almost have to keep playing with the accelerator pedel to keep it going. Only problem I have had with a TPS before was that the truck would not run at idle but ran fine above idle.

Back to the primary question - if I watch the TPS signal, shouldn't it start somewhere around .525 and go up when I rev the engine up?

Thanks again for your help.

 

Back to the primary question - if I watch the TPS signal, shouldn't it start somewhere around .525 and go up when I rev the engine up?

Yes. You may have a wiring or E.C.M. problem if the new sensor doesn't fix it. It is adjustable, you need around .5 V first. (at idle)

 

The range is .525 to 4.5 volts at WOT.

Easy to set. Make sure your meter is accurate. Insteady of making a jumper I used two paper clips. its wires A and B (two bottom ones).Staighten the paper clips and push them into the connector. make sure they are not touching. Then attach your meter to the paper clips. Car does not have to be running to make the adjustment but the ignition must be in the "on" position.

Its very sensitive and takes a bit of playing with. i found that the setting changed as I tightened the screw. Took a few trys to get it exact.

By the way according to the manual. Code 21 is a bad TPS or adjustment issue. Code 22 suggests something else. Test for code 22 is checking voltage on pin A and C over 4.6 volts indicates a short on cicuit 417 (goes to black ECM connector) or bad connection at the ECM. Below 4 volts suggests a problem on the white connector on the ECM or circuit 416 (goes to white ECM connector) is shorting to ground. If the white connector is good and there is no short to ground on 416 is says bad ECM.

Interesting that you also got code 33. MAP also shares circuit 416 on the white connector. 416 runs off pin "C" at the MAP.

Its been a while but I think CTS 416 runs into a black box on the passengerside firewall...along with the other wires ,injectors,IAC.s etc. There are several large connectors in that box. Sometimes they short or the connects rust. You should take a look.

Jim

 

Holy Mackerel !
Thanks for the info ! I will go to work on it and let you know where I end up. You gave me exactly what I was asking for, now maybe I can actually do something right with it. I had assumed that if I have my scanner hooked up to it and am reading the voltage outputs, that I should see the change. But, as you pointed out, it may not be the sensor. thanks again. I really appreciate the help and input.

Buddy

 

We have been round and round and round on this topic....Checkout this linc for tuning your 82

....http://www.corvettefever.com/techart...ing/index.html

print it and read it several times then do it. Makes a world of differance. good luck

 

thanks Bluesilver82.
I did as you said and printed the entire thing, plus, I then blew it up in size and printed it again. I read it, and will read it again before bed.
And, I will do it - once I get whatever broke repaired. Whatever went out did so about 1 mile from the house. All was well until then, and at that point, it was a pile of vibrating, sputtering, lopping mess. Something went quickly.

Again, thanks for you help. I will do as you suggest.
Buddy
PS - before this, I was getting about 20 mpg with it. Of course it is not a muscle car in its original state, but sure fun to drive, but still goes pretty good.


It is bed time here for old men! Will do more tomorrow.

 

The '82's ECM will go into what they call a "limp home mode" when it sees sensor problems. It can be caused by any of the sensors or a bad ECM. I went round & round with mine and finally replaced all the senors (since it had 110K miles on anyway) and it worked fine and then 3 months later the ECM crapped out and I replaced that! Everything works good now, it better!
So after you set the TPS and it still runs bad, look at other senors. Check for trouble codes first. If no codes then you may have to change them to see if that helps. The MAPP is easy, just unplug the vacuum line to it and you will hear a change in the engine, if no change then it's bad.
It's a real PIA, hope you find the answer.
Dave

 

Thanks again! You guys just keep coming in to help me and I appreciate it. I didn't get to do anything on the vette today as the home electrical is being modified and it will be completely off tomorrow. I will attempt to get back to the vette day after tomorrow and let you guys know what I find - or don't find.

Thanks again, and I will get you an update as soon as I can.
Buddy