Pumpkinhead65

I was driving my wife's 2007 GT 4.6 Nov 2016 when, while sitting at a light, the idle got a little rough, a wrench light on the dash lit up, and I had ZERO throttle response. I was clueless. WTH just happened? It didn't happen again until about 10 months later and then increased in frequency a lot. Last week it happened almost 20 times on my 45 minute commute home. Aggravating and unsafe. I read and read and found MANY others plagued & perplexed with the same problem.

She bought this car from a little dealer just before we met 2 years ago so we have no idea what mods may have been done but it does have a 62mm BBK TB. I replaced the TPS with a FoMoCo one. No change. Replaced the MAF Sensor with a new one from Advance Auto. No change. I cleaned the already clean looking TB with carb cleaner. No change.

Then I stumbled across the concept of TPS voltage (drive-by-wire is completely new to me) and read and read some more. Lots of info. It was reading @ 1.115v. Someone said it should be 1.19 to 1.3. I set it to 1.25 and that made it worse. Very high idle and RPM was very reluctant to come back down once up.

I read and read some more then started lowering the voltage until I tried 0.98v and BAM! The idle is low and smooth around 650rpm, smooth driving, great power and no more wrench light and codes.

If you aren't sure how to adjust the TPS voltage for idle, you should be able to Google for details but here are the highlights w/o pics...

1. Disconnect throttle actuator motor (plug on driver side of TB.
2. Using a digital voltage meter (DVM), ground to the block & red lead to the yellow wire (bottom of 4 wires on the TPS - passenger side of the TB.
3. KOEO, Check reading.
4. Turn key off.
5. Remove the throttle actuator from the driver side of the TB, loosen the tiny hex set screw holding the brass "bolt" on the driver side of the TB.
6. KOEO, hook up your DVM again and turn the brass "bolt" until the DVM reads 0.98v.
7. While holding the brass "bolt steady, tighten the set screw.

NOTE: while adjusting the voltage, I manually held the TB coil spring in place tightly, which mimics the assembled throttle actuator assembly and allowed the butterfly plate to be FIRMLY in the correct position.

Worked for me and I hope this helps someone else but YMMV.

07 Cali Special

Thank you so much for sharing this! I was having similar issues on my 07 4.6L! I however had bought the BBK intake and installed myself. I took it out of the box which included the throttle body and a card IF I wanted to download instructions.

I put the Throttle body on figuring oh this is simple enough, what can go wrong ? WRONG to ASSUME!
WRONG to not research and watch a simple installation video!!! car ran fantastic for 3 days Despite not reading instructions. Then poof!!! It died and threw codes 2104 & 2111,

Many calls later, many visits to anyone who knows anything about cars and so many opinions later, I tried and tested each of these to no avail.

i found this post which was SPOT on and followed the instructions. Set the TPS Voltage to .98 and started the car. Still the same result at first, in fact worse it was idling like a cylinder or 2 was down. I thought the girl who just turned 150,000 miles was DONE!

I checked codes with my Bama tuner and there’s good old 2104 & 2111 again
well a slight sigh of relief that there were no codes indicating a blown engine, despite the horrible idle!
i was about ready to give up and something told me to clear codes, so I did. Just as I was ready to call a tow or try to get my local mechanic to make a road call the next day, I decided out of desperation or futility to take one LAST shot.

She Roared to life again!!! I was stunned in disbelief after 3 days of futile efforts.

So Thank you so much for posting this. As you wished you helped someone else!!

Rj Garza

😅😅😅 I'm sorry I'm new to cars what's a throttle body actuator and what bolt do I lossen cause I'm very confused