How to modify TPS bracket to get WOT up shift to OD
02-07-2004, 01:28 AM
#1
Registered User
Thread Starter
How to modify TPS bracket to get WOT up shift to OD
Did some more tinkering today, wow am I ever having a blast with this!
Decided to pull out my nylon washer and shave it down. It was .144" and I took it down to .100". Did not seem to make a difference that I could notice.
But while I did have it apart I found something interesting with the TPS. Since I modified my throttle linkage to get more travel I have not been able to get a WOT upshift to OD. Even at 3000RPM and 75MPH. What I found is that with the extra travel of the throttle my TPS was reading over 4.0volts at WOT. This is with it adjusted all the way down so that it read 0.2V at low idle. So what I needed was to be able to turn the TPS down lower.
Once taken apart I could see that the TPS has all small block like a keyway on the shaft that moves inside a little window in the mounting bracket for the TPS. This little window controlled how far it would go on the high side and low side. My problem was that it would not let me 'retard' or turn the TPS down low enough so that at full WOT I would have a voltage of less than 4.0V.
Solution: grind back the window to make it bigger allowing the TPS to be turned down farther. So I ground back the stop a bit, didn't take much. Then I installed the TPS back onto the bracket and backed it off as much as possible, at this point the spring in the TPS was completly unloaded and just sort of floating. Then I carefully indexed the Hex nut on the TPS to the throttle shaft so that it would drop straight on. Then I installed the TPS/bracket assembly. I originally set the TPS voltage for 2.4V at WOT(don't worry about the low idle voltage). On the test drive I found at WOT it upshifted at about 45MPH. Way too low but atleast I knew I was on the right track! Adjusted the WOT voltage upto 3.0V and then had upsift at 55MPH.
Adusting WOT voltage to 3.4V then resulted in upshift at about 65MPH. Going to try it there for awhile and see.
Basically what I have done is moved the TPS back so far that it takes about a 1/4 of the throttle travel before it acts on the TPS making a voltage change. This can been seen by watching the voltage while slowly advancing the throttle. At rest it is .2V and does not rise untill the throttle is advanced about 1/4 of its travel. Then it rises normally to the value you have set.
Also I have noticed that the one hill I pulled it seemed to delay the upshift about 5MPH. So it still reponds to load changes.
Hope this helps some people, I know it was really buggin me!
Decided to pull out my nylon washer and shave it down. It was .144" and I took it down to .100". Did not seem to make a difference that I could notice.
But while I did have it apart I found something interesting with the TPS. Since I modified my throttle linkage to get more travel I have not been able to get a WOT upshift to OD. Even at 3000RPM and 75MPH. What I found is that with the extra travel of the throttle my TPS was reading over 4.0volts at WOT. This is with it adjusted all the way down so that it read 0.2V at low idle. So what I needed was to be able to turn the TPS down lower.
Once taken apart I could see that the TPS has all small block like a keyway on the shaft that moves inside a little window in the mounting bracket for the TPS. This little window controlled how far it would go on the high side and low side. My problem was that it would not let me 'retard' or turn the TPS down low enough so that at full WOT I would have a voltage of less than 4.0V.
Solution: grind back the window to make it bigger allowing the TPS to be turned down farther. So I ground back the stop a bit, didn't take much. Then I installed the TPS back onto the bracket and backed it off as much as possible, at this point the spring in the TPS was completly unloaded and just sort of floating. Then I carefully indexed the Hex nut on the TPS to the throttle shaft so that it would drop straight on. Then I installed the TPS/bracket assembly. I originally set the TPS voltage for 2.4V at WOT(don't worry about the low idle voltage). On the test drive I found at WOT it upshifted at about 45MPH. Way too low but atleast I knew I was on the right track! Adjusted the WOT voltage upto 3.0V and then had upsift at 55MPH.
Adusting WOT voltage to 3.4V then resulted in upshift at about 65MPH. Going to try it there for awhile and see.
Basically what I have done is moved the TPS back so far that it takes about a 1/4 of the throttle travel before it acts on the TPS making a voltage change. This can been seen by watching the voltage while slowly advancing the throttle. At rest it is .2V and does not rise untill the throttle is advanced about 1/4 of its travel. Then it rises normally to the value you have set.
Also I have noticed that the one hill I pulled it seemed to delay the upshift about 5MPH. So it still reponds to load changes.
Hope this helps some people, I know it was really buggin me!
Thread
Thread Starter
Forum
Replies
Last Post
Moobesor
3rd Gen High Performance and Accessories (5.9L Only)
1
05-22-2008 06:35 PM
ratat98
Performance and Accessories 2nd gen only
29
08-11-2006 09:41 PM