PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

TPS won't reset/zero

Thread Tools
 
Search this Thread
 
Old May 5, 2020 | 04:38 PM
  #1  
kdick91's Avatar
Thread Starter
TECH Regular
15 Year Member
iTrader: (1)
 
Joined: Dec 2008
Posts: 417
Likes: 20
From: Houston, TX
Default TPS won't reset/zero

So I've been chasing this idle issue and narrowed it down to my TPS. I've got a cam in my car and the tuning is dialed perfect, PatG took care of it. I've opened up the TPS holes, reclocked, it's 0.50v when the throttle is closed, and done probably 20 relearn procedures. Every time I key on, the TPS is at 2.0% and making the idle suck. The only time I can get the TPS to 0.0%-0.4% is when I flash a new tune. If I hit the key after flashing, it fires up, AC on and in gear, idles perfect. If I cycle the key, TPS is back at 2.0% and it won't idle right.

The 5v reference on the sensor is at 4.95v and the ground ohms to zero anywhere on the block. I'm going crazy trying to chase this issue. WOT always shows 100% as it should. I cannot figure out why the car wants TPS to be 2% every time I cycle the key! Any help is greatly appreciated!
Reply
Old May 6, 2020 | 10:45 AM
  #2  
RonSSNova's Avatar
8 Second Club
10 Year Member
Photogenic
Photoriffic
Top Answer: 1
iTrader: (3)
 
Joined: Aug 2011
Posts: 4,729
Likes: 814
From: Portland, OR
Default

Throttle cable too tight?
Do the volts return to .500v
Reply
Old Jun 6, 2020 | 10:02 AM
  #3  
kdick91's Avatar
Thread Starter
TECH Regular
15 Year Member
iTrader: (1)
 
Joined: Dec 2008
Posts: 417
Likes: 20
From: Houston, TX
Default

I did solve this issue. I used a pink wire for my wideband, dumb decision. When the O2 heater kicked on, it caused a voltage dip going to the PCM and when the heater turned off, voltage came back up which the PCM detected as me rolling on the throttle slightly. Added a relay like I should have in the first place and all is gravy now!
Reply
Old Jun 10, 2020 | 09:00 AM
  #4  
RonSSNova's Avatar
8 Second Club
10 Year Member
Photogenic
Photoriffic
Top Answer: 1
iTrader: (3)
 
Joined: Aug 2011
Posts: 4,729
Likes: 814
From: Portland, OR
Default

Good find!
Reply
Old Jun 11, 2020 | 07:56 PM
  #5  
MUSTANGBRKR02's Avatar
12 Second Club
iTrader: (91)
 
Joined: Aug 2006
Posts: 4,599
Likes: 5
From: Maine
Default

That is a good find and follow up.
Reply




All times are GMT -5. The time now is 02:31 AM.

story-0
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-1
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-2
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-3
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-4
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-5
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-6
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE