Liberator*21
08-07-2012, 12:21 PM
This will apply to "SOME", not all 300x motors. Some, don't know why, have a problem with linkage bind because of the direct linkage rod angle from the throttle cam to the TPS ball socket. This can be seen at the TPS when applying throttle, the entire TPS wants to move until enough pressure is applied to slighty change the angle of the linkage. If left as is will cost you a TPS sooner or later, I speak from very recent experience. I bought a new TPS and after mounting it and checking the TPS voltage I noticed the binding just by moving the throttle arm by hand (cable disconnected). This is how I fixed the problem. Please note that an OEM TPS ROD will now be to short, an adjustable rod must be made up to make up for the increase in distance due to the TPS rotation.
Hers an older pic of the adjustable rod I made;
http://i177.photobucket.com/albums/w201/90profx/TPS%20Link%20Rod/TPSROD010.jpg
Made a new TPS bracket out of 1/8", 6061-T6 aluminum plate using the OEM bracket as a pattern. Two things were modified from the OEM bracket, the 4 TPS threaded holes were rotated 5 degrees "CW" as was the center clearence pocket. This opening is for the expoy bead on the back of the TPS sealing the rear cover to the body, as it won't sit flush on a flat surface due to the epoxy bead. So here it is is photos:
Here you see the stock bracket and the one I fab'd up;
http://i177.photobucket.com/albums/w201/90profx/TPS%20Mounting%20Plate/Bracket1.jpg
This pic shown the 5 degree threaded hole rotation "CW" from the stock position marked "X";
http://i177.photobucket.com/albums/w201/90profx/TPS%20Mounting%20Plate/TPSPlate003.jpg
This pic is with the hole tapped and the clearence hole in the center for the epoxy bead on the back of the TPS;
http://i177.photobucket.com/albums/w201/90profx/TPS%20Mounting%20Plate/TPSPlate005.jpg
TPS mounted to the new bracket, it's now obvious to see the TPS plug is now angled upwards from where it's normally center between the 2 forward mounting screws;
http://i177.photobucket.com/albums/w201/90profx/TPS%20Mounting%20Plate/TPSPlate006.jpg
My DDT showing that after 10 throttle advances from idle to WOT, the TPS voltage always falls back within spec. +/- .008;
http://i177.photobucket.com/albums/w201/90profx/TPS%20Mounting%20Plate/TPSPlate007.jpg
Hers an older pic of the adjustable rod I made;
http://i177.photobucket.com/albums/w201/90profx/TPS%20Link%20Rod/TPSROD010.jpg
Made a new TPS bracket out of 1/8", 6061-T6 aluminum plate using the OEM bracket as a pattern. Two things were modified from the OEM bracket, the 4 TPS threaded holes were rotated 5 degrees "CW" as was the center clearence pocket. This opening is for the expoy bead on the back of the TPS sealing the rear cover to the body, as it won't sit flush on a flat surface due to the epoxy bead. So here it is is photos:
Here you see the stock bracket and the one I fab'd up;
http://i177.photobucket.com/albums/w201/90profx/TPS%20Mounting%20Plate/Bracket1.jpg
This pic shown the 5 degree threaded hole rotation "CW" from the stock position marked "X";
http://i177.photobucket.com/albums/w201/90profx/TPS%20Mounting%20Plate/TPSPlate003.jpg
This pic is with the hole tapped and the clearence hole in the center for the epoxy bead on the back of the TPS;
http://i177.photobucket.com/albums/w201/90profx/TPS%20Mounting%20Plate/TPSPlate005.jpg
TPS mounted to the new bracket, it's now obvious to see the TPS plug is now angled upwards from where it's normally center between the 2 forward mounting screws;
http://i177.photobucket.com/albums/w201/90profx/TPS%20Mounting%20Plate/TPSPlate006.jpg
My DDT showing that after 10 throttle advances from idle to WOT, the TPS voltage always falls back within spec. +/- .008;
http://i177.photobucket.com/albums/w201/90profx/TPS%20Mounting%20Plate/TPSPlate007.jpg