TPS Adjustment Help
Thread Starter
Heel & Toe
Joined: Dec 2010
Posts: 16
Likes: 0
TPS Adjustment Help
Hey guys, need someone to set me on the right path here. I got my first vette 3 months ago, and still not driving it...ugh! I've learned alot here, but in reading the forums, I cannot find the answer for the TPS adjustment problem I'm having. Let it be known, as with many, my skills with electrical devices is lacking, but I was able to get a couple of paperclips into the top 2 wires (A&B) on the TPS wiring harness and check the voltage. I've read that the voltage should be .54, but I'm getting.24...about half what I need. I did start her up and check as well, but got the same reading. With the engine started, I can depress the TPS arm to get a .54 reading, but it's about half way through it's total motion to acheive this. There is no way that I can set the minimum idle speed that high to acheive the volatade I need...the TPS would almost need to point to the sky. However, when I depress the TPS arm while she is running to get the .54 volts...it sounds awesome!!! From what I can understand from the wire diagram, these wires run straight to the ECM...please help! What should I check here?
Jeff
Jeff
Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
Jeff, I know how you feel about electrical things on these cars.
Connect your volt meter to the top two wires (where you have your paper clips). Turn on the key, but do not start the car. If your reading is .24 volts then you need to loosen the two torx screws on the TPS. You want them slightly loose so you can move (twist) the TPS up and down and it will stay in position....not hanging loosely from the screws. Now twist the TPS and watch the reading. Twist it until you get a reading of .54 volts. Now tighten the screws. Now if you take the throttle and open it wide open you should get a reading of 4.49 volts. Both of these measurements are plus or minus .075 volts. There is some play in the TPS slots so you can move it around to eventually get both of these readings. It takes a little trial and....more trial
.
Keep at it and you will get it adjusted.
Connect your volt meter to the top two wires (where you have your paper clips). Turn on the key, but do not start the car. If your reading is .24 volts then you need to loosen the two torx screws on the TPS. You want them slightly loose so you can move (twist) the TPS up and down and it will stay in position....not hanging loosely from the screws. Now twist the TPS and watch the reading. Twist it until you get a reading of .54 volts. Now tighten the screws. Now if you take the throttle and open it wide open you should get a reading of 4.49 volts. Both of these measurements are plus or minus .075 volts. There is some play in the TPS slots so you can move it around to eventually get both of these readings. It takes a little trial and....more trial
.Keep at it and you will get it adjusted.
Thread Starter
Heel & Toe
Joined: Dec 2010
Posts: 16
Likes: 0
John, thanks. Indeed I have tried with no luck. With the TPS adjusted counterclockwise (to the fartherest position), I can only get the .24 volts. With the throttle wide open, I'm getting 1.3 volts. I will try again tomorrow, but again, the TPS arm had to be depressed half-way down to get the .54 volts...aarrgg! I did not see that the wires had fuseable links, or any way back to the fusebox, so I'm hoping (maybe) that someone has some fairy dust I can throw on the TPS and have it magically work.
Thread Starter
Heel & Toe
Joined: Dec 2010
Posts: 16
Likes: 0
Dog-gone-it! I just picked this one up from the dealer ($110 bucks), but you may be right. Do you know of a way to check it out to know for sure...or is that what I'm doing now?
Jeff
Jeff
Last edited by CouchJ85; Jun 29, 2011 at 02:07 AM. Reason: typo
Team Owner
Joined: Jan 2003
Posts: 20,304
Likes: 240
From: Summerland B.C. Canada
Try it with your meter connected and see if you can get it to .54v.
Thread Starter
Heel & Toe
Joined: Dec 2010
Posts: 16
Likes: 0
Moving the TPS forward and rear did not produce any results. Indeed it is a "floating" mechanism, but rotating the entire unit counterclockwise to receive maxium voltage (depressing the TPS arm w/ TB linkage) leaves me with low voltage. As far as voltage to the TPS, do I unplug the TPS and just measure the top two wires, or find the "hot" and a ground? I feel so inadequate, my father would be ashamed!
Ok, just got back from testing. I placed one (I think it's called a prong) on the "C" and the other on either "B" or "A" and got 5.03 volts...WOOHOO! So, the TPS may be bad...dang-it!
Ok, just got back from testing. I placed one (I think it's called a prong) on the "C" and the other on either "B" or "A" and got 5.03 volts...WOOHOO! So, the TPS may be bad...dang-it!
Last edited by CouchJ85; Jun 29, 2011 at 11:01 AM.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
