PTM 92 Throttle Body: W-T-F!
07-17-2016, 06:11 PM
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PTM 92 Throttle Body: W-T-F! I have an LS1 GTO which I just put a used FAST 92 manifold and used PTM TB on. After trying all possible throttle cable adjustments and positions on the actual TB, pedal to the floor was only able to get the throttle blade about 70% open.
I have emailed/called Texas Speed tech support and they had no answers for me. I've also been unable to find any instructions online that might help me out. Finally the gentleman who tunes my car was able to make some calls and get me an idea of what the issue may be. According to him the throttle return springs are far too strong causing issues within the TCS/cruise/throttle, and I can confirm that the spring was extremely stiff to the point of being difficult to actuate by hand.
I ended up ordering another throttle return spring from PTM/Texas Speed and noticed they shipped two springs, with one being slightly larger than the other. When I took off my throttle body I noticed it indeed had two return springs with the smaller spring sitting inside the larger. I ended up simply removing the larger of the two springs and leaving just the smaller spring on the TB, the resulting pressure seemed comparable to the stock TB spring pressure. I reinstalled and confirmed I was getting the TB to open and close fully and the test drive went fine. My concern is that this single spring may lead to throttle sticking or other unforeseen consequences.
My question is: Has anyone else had this issue (yes I searched)? Do other PTM TB owners run two springs without issue? Does anyone else run just a single return spring? Thanks!
I have emailed/called Texas Speed tech support and they had no answers for me. I've also been unable to find any instructions online that might help me out. Finally the gentleman who tunes my car was able to make some calls and get me an idea of what the issue may be. According to him the throttle return springs are far too strong causing issues within the TCS/cruise/throttle, and I can confirm that the spring was extremely stiff to the point of being difficult to actuate by hand.
I ended up ordering another throttle return spring from PTM/Texas Speed and noticed they shipped two springs, with one being slightly larger than the other. When I took off my throttle body I noticed it indeed had two return springs with the smaller spring sitting inside the larger. I ended up simply removing the larger of the two springs and leaving just the smaller spring on the TB, the resulting pressure seemed comparable to the stock TB spring pressure. I reinstalled and confirmed I was getting the TB to open and close fully and the test drive went fine. My concern is that this single spring may lead to throttle sticking or other unforeseen consequences.
My question is: Has anyone else had this issue (yes I searched)? Do other PTM TB owners run two springs without issue? Does anyone else run just a single return spring? Thanks!
07-20-2016, 01:02 PM
#2
I had a similar problem on my Fast 92 setup (F-body). I ended up having to bend the gas pedal at the top near the linkage in order to get the throttle to open fully. Didn't have any issues with the springs tho.
07-20-2016, 06:16 PM
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CherrySS,
Thanks for the response! I tried something similar, it allowed me to get the throttle blade wide open but it would not seat closed to idle. I'm more or less 100% sure it is an issue with the return spring specifically in this case. If I do get throttle sticking I could just trash the PTM and get A FAST or Nick Williams. For now I'll try this rigged up PTM. Any other suggestions or experiences would be appreciated if anyone has any!
Thanks for the response! I tried something similar, it allowed me to get the throttle blade wide open but it would not seat closed to idle. I'm more or less 100% sure it is an issue with the return spring specifically in this case. If I do get throttle sticking I could just trash the PTM and get A FAST or Nick Williams. For now I'll try this rigged up PTM. Any other suggestions or experiences would be appreciated if anyone has any!
08-01-2016, 06:45 AM
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UPDATE:
I was able to get the car tuned using a single return spring, but after more street driving the blade is sticking both open and closed quite severely.
Conclusion From My Ordeal: If you have an LS1 GTO AVOID THE PTM THROTTLE BODY. The return spring is too strong for the GTO specific throttle/traction control system to work with. Texas Speed/PTM do not have a solution nor will they assist you in solving the issue from my experience.
I was able to get the car tuned using a single return spring, but after more street driving the blade is sticking both open and closed quite severely.
Conclusion From My Ordeal: If you have an LS1 GTO AVOID THE PTM THROTTLE BODY. The return spring is too strong for the GTO specific throttle/traction control system to work with. Texas Speed/PTM do not have a solution nor will they assist you in solving the issue from my experience.