Throttle body issues
Thread Starter
Heel & Toe
Joined: Apr 2019
Posts: 21
Likes: 1
Throttle body issues
I have a 1999 frc that is having a 418 ls3 swap done to it. It has a nw 102mm throttle body on it with a fast 102mm intake. The car fires up and idles but there is no response from the throttle body when pressing the throttle inside the car. There are no codes. Any input on what could be wrong? First guess is the tac module could have went bad.
Thread Starter
Heel & Toe
Joined: Apr 2019
Posts: 21
Likes: 1
Thanks for the input. The car is at a shop about an hours drive away and I am headed there tomorrow with the stock throttle body that came off of it to test and see if it will work. Any ideas I can bring with me might save some time and headaches since they have worked on it for several hours and haven't found a solution.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,594
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From: Cape Coral, Florida
As gimp had mentioned have the shop check TAC Module power and grounds and TAC motor... APP and TPS are simple potentiometers using a 5 volt reference, signal, and a low reference (ground). Good luck !!
Thread Starter
Heel & Toe
Joined: Apr 2019
Posts: 21
Likes: 1
So I went to the shop just now and I guess I misunderstood over the phone what the car was doing. The car is going into reduced power mode. I saw this problem in several posts with the nw 102mm throttle body. We hooked up the stock throttle body and it's still doing the same thing. Is there any fix for this? There are no codes being thrown. If anyone can point me in the right direction. The tac module looks like it had been opened in the past also.
Thread Starter
Heel & Toe
Joined: Apr 2019
Posts: 21
Likes: 1
Yes the guy at the shop had his laptop with his tuning software hptuners and that was the only thing showing up reduced engine power. No codes at all. He had never seen this before. The throttle body did the thing where it opened at the beginning when the key is turned. After that the throttle body would only crack open a tiny bit when pressing the accelerator even while the engine was running. We tried the nw 102mm tb a stock ls1, ls2, ls3 basically every one he had at the shop and we ended up with the same result every time. I'm a bit stumped on what to try next. Every wire running from the accelerator to the tac module to the throttle body was traced and everything seemed to check out fine. We are just guessing things to try now but i'm guessing it could be something in the tune itself. Anyone that has any ideas they are welcome. We are going to try and find a loaner tac module to see if that does anything instead of buying one as they are pretty hard to find and expensive.
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Drifting
Joined: Jul 2015
Posts: 1,844
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From: San Jose, CA
And hypothetically, this is a really silly question, but did you try to clear all the codes (even if none show up), disconnect/reconnect the battery, etc, to reboot the system?
And while I am sure the hptuners laptop works great, did you try to read the DIC codes? There's a non-zero chance something would show up there.
Or use a tech2 (real or knockoff)?
And while I am sure the hptuners laptop works great, did you try to read the DIC codes? There's a non-zero chance something would show up there.
Or use a tech2 (real or knockoff)?
Thread Starter
Heel & Toe
Joined: Apr 2019
Posts: 21
Likes: 1
Everything was tried you mentioned to clear codes while I was there. I didn't personally try and read the DIC codes that come up on the dash. I will try it next time I drive over there (hopefully tomorrow). I will also see if they tried to use anything other than the laptop to read the codes. Is there any way to shut off the codes from showing up? I failed to ask that while I was at the shop as I didn't really think of it at the time.