Throttle Body (Nick Williams) or Gas Pedal Issues

[Genobee]

Hey all,

I got a 5th gen ZL1 with a couple mods done to it. Recently I started having some issues with the throttle body. I was getting engine codes P2135 and 2138 and the engine goes into limp mode.

Both are voltage correlation issues which means that the throttle body sensor is not agreeing with the gas pedal sensor. The TB is a Nick Williams 102mm, but it's the older generation with the longer servo/motor housing.

I can replicate this issue perfectly with the engine off and key ignition on. If I step almost all the way down (you can hear the throttle body move), it will cause one or both of these codes to come up. Usually it's P2135, especially if it's when doing some "spirited driving".

I'm trying to figure out if there's a way to test whether it's the throttle body or the gas pedal. It always happens when I'm about 80-90% of the way into the pedal. I pulled out the TB and cleaned it while avoiding manhandling it as much as possible so I don't damage the sensor or the motor, but that didn't do much. I will say that there was a good amount of methanol deposit on it, which was harder to clean up than the carbon buildup.

Anyway, these are my mods, pushing about 700 WHP on ~E70:

Ron Davis Racing ZL1 Heat Exchanger
Aluminum Polished Separator tank
Big 3 Racing Overflow Expansion tank
Single Nozzle Meth kit
2.5 Gallon Tank Upgrade
Port Supercharger Snout
Nick Williams 102mm Throttle Body
TFS 255X Cylinder Heads
Cylinder Head Changing kit with ARM Hardware and MLS gaskets
ZL1 Headers Cats
ZL1 ID850 Injectors
ZL1 Stage 3 Cam/gaskets/etc
NGK Spark plugs
Supercharger Pulley 2.5 ZL1-CTSV
E85 Flex fuel
Boost-a-pump (will be upgrading to a more legit fuel system soon)

Any thoughts on how to test for a failing pedal vs. TB would be really appreciated, though my money's on the TB.

I've heard the older Nick Williams 102mm had issues with boosted applications (it would just pull air right through the TB). But it seems pretty odd that I can reproduce it even when the engine is off (there's no air flowing, so what's the deal?)

Thanks for your time.

[GODZL1A]

I’ve had the same issues with the NW throttle body and I’ve used the old one and the new boosted one that being said there’s a lot of people out there with no issues if I were you I’d put the stock throttle body back on and see if it fixes it �� it did for me

Dave

[Genobee]

Originally Posted by GODZL1A

I’ve had the same issues with the NW throttle body and I’ve used the old one and the new boosted one that being said there’s a lot of people out there with no issues if I were you I’d put the stock throttle body back on and see if it fixes it �� it did for me

Dave

I actually don't have the stock throttle body anymore but thanks for the suggestion. If I don't hear back from other peeps, I might just order the new gen Nick Williams and cross my fingers. I might give them a call too and see if they know of these issues.

[Juiced1]

It sounds like a throttle body issue or a short. I have never ran into an issue with a pedal. Find someone else with a 102 (or any other tb i guess) locally and swap them for a day and see if that works.

I've ran into the same issue with a short before. Anytime it was raining/damp it would run into that same code. So we put silicon on all the connections from the wiring harness and it seemed to stop it.

[Genobee]

Originally Posted by Juiced1

It sounds like a throttle body issue or a short. I have never ran into an issue with a pedal. Find someone else with a 102 (or any other tb i guess) locally and swap them for a day and see if that works.

I've ran into the same issue with a short before. Anytime it was raining/damp it would run into that same code. So we put silicon on all the connections from the wiring harness and it seemed to stop it.

That's a pretty good idea too, might visit my local shop and see if they have one I can test out. I don't think it's a short, because of how consistently I can reproduce the issue by getting the pedal+TB to a certain % of open. If it's a short, it would likely fail randomly or right when I start the car... Definitely worth double checking though.

[JTORR428]

ive had issues with my nick Williams 102 tb . ended up buying a new one and that one went bad on me too. try going back to stock

[Vicster]

Hello,
This is late but I had the exact same issues with a 95mm BBk throttle body, went to a LS3 throttle body issue went away. I gave up some power but at least it runs fine now.

[owhite3003]

Had a buddy that had an issue with the peddle sensor. We had 3 zl1s running down the west coast and out of nowhere he started having issues. Pulled over and unplugged the battery and it reset itself. Ran for another 100 or so miles and had the same issue. Reset it again and almost made it to our destination and it happened again. Took it to a dealer and they found that the peddle sensor had gone bad. I would install the stock TB and retest like it is said in the above post. Let us know what you found out. Good luck.

[Crash76]

I have a stock tb if you want to try it out... if your cant find someone locally.

Just paypal me a deposit, ill send it to you, when you are done and I get it back ill paypal you back.

Obviously you are better off finding it locally