LilYellowZQ8
11-28-04, 10:12 PM
The TPS modification for 1996+ OBD2 Equipped Vehicles.
The TSP (Throttle Position Sensor) is used to tell the OBD that you are accelerating. It is merely a rheostat and a rheostat is merely a voltage controller. It works between 0-5 volts, under .8 volts tells the OBD that your in and idle mode, 4.5+ volts, it tells the OBD your under a WOT (Wide Open Throttle) mode. As you begin to accelerate the OBD receives a voltage signal which tells the OBD what your intentions are and based on the voltage input it begins to pick a timing and fuel map based your acceleration needs. The stock TPS has and over travel built into it, the throttle plate moves just under 90 degrees while the TPS has around 105 degrees of travel built it so it never pins to one side. Problem is that stock they read roughly .3-.6 volts at idle and roughly 4.4-4.6 volts at WOT. What is the problem? Well if the OBD is programmed for under .8 volts being idle and 4.5 volts being WOT, it takes roughly 10-15% of its travel for the OBD to see that idle isn’t being maintained and at WOT the OBD may not see the voltage for max timing and fuel curves since it may not get over 4.5 volts. This results I the lag most experience when then mash the throttle, it takes a second of 2 before the OBD begins its timing and fuel advancement. On the other end it may never give total timing and fuel curves allowed since it wont met the 4.5volt minimum requirement for WOT. What we are going to do next is show you how to modify the TPS to eliminate this problem.
http://njsr.org/pics/albums/userpics/10757/TPS1.JPGThis is your TPS mounted on the drivers side front of the throttle body. You will need to remove the bonnet from the throttle body and rubber inlet off the MAF to remove it. It has 2 torx screws holding it on. Remove the wire clip and undo the 2 screws to remove. T-25 Torx.
http://njsr.org/pics/albums/userpics/10757/TPS2.JPG
http://njsr.org/pics/albums/userpics/10757/TPS3.JPGThis is the TPS off the throttle body.
http://njsr.org/pics/albums/userpics/10757/TPS4.JPG
Here on the back of the TPS is a position tab, it must be removed in order for you to complete this mod. You are going to be turning the TPS counterclockwise to advance the voltage setting. A file, dremel or in this case a razor knife is needed to remove the tab.
http://njsr.org/pics/albums/userpics/10757/TPS5.JPGHere again is the TPS showing the front side.
http://njsr.org/pics/albums/userpics/10757/TPS6.JPGYou see in the arrows in the picture. You need to elongate the holes towards the arrow points so you can advance it. You can use a drill bit, small rattail file, dremel etc to move the holes as close to the outer rim as you can and actually remove the rim.
http://njsr.org/pics/albums/userpics/10757/TPS7.JPGKinda like this picture. Front facing hole will elongated from its current position towards the top edge. The rear screw hole from its current position toward the bottom. This allows a counterclockwise resetting. One its done remount the TPS back onto the throttle body.
http://njsr.org/pics/albums/userpics/10757/TPS8.JPGHere you see a voltage measurement being taken. With the meter probes, take the positive probe and place it into the blue wire, negative probe into the black wire. Turn key to the on position. You want it to read .7-.8 volts in the idle setting, you loosen the TPS screws and move it counterclockwise until it reads .7-.8 volts and tighten.Don’t have a meter, you can just rotate it counterclockwise about ¼ the screw size.
http://njsr.org/pics/albums/userpics/10757/TPS9.JPG
In this picture we’ve moved the throttle to the WOT position to see that over 4.5 volts was achieved.
Once its set drive it for a short trip down the road. If its returns to idle with no problems, you’ve done it and could try to move it some more or leave it. If idle is effected move it back .1 volts or in case of no meter, just move it back very little and try again until idle is not effected. This will remove almost all the delay and get a jump earlier on the timing and fuel map. Caspers TPS enhancer is advertised to do this also, but it does not, it merely tell the OBD that at 75% throttle its at 100% so it still has this lag in it.
This is the basics and isn’t always the case. Some model years the voltage and idle is different. So with the probes you can get a base reading at idle position and then increase the base setting up to .4 volts more, but same basic principle.
The TSP (Throttle Position Sensor) is used to tell the OBD that you are accelerating. It is merely a rheostat and a rheostat is merely a voltage controller. It works between 0-5 volts, under .8 volts tells the OBD that your in and idle mode, 4.5+ volts, it tells the OBD your under a WOT (Wide Open Throttle) mode. As you begin to accelerate the OBD receives a voltage signal which tells the OBD what your intentions are and based on the voltage input it begins to pick a timing and fuel map based your acceleration needs. The stock TPS has and over travel built into it, the throttle plate moves just under 90 degrees while the TPS has around 105 degrees of travel built it so it never pins to one side. Problem is that stock they read roughly .3-.6 volts at idle and roughly 4.4-4.6 volts at WOT. What is the problem? Well if the OBD is programmed for under .8 volts being idle and 4.5 volts being WOT, it takes roughly 10-15% of its travel for the OBD to see that idle isn’t being maintained and at WOT the OBD may not see the voltage for max timing and fuel curves since it may not get over 4.5 volts. This results I the lag most experience when then mash the throttle, it takes a second of 2 before the OBD begins its timing and fuel advancement. On the other end it may never give total timing and fuel curves allowed since it wont met the 4.5volt minimum requirement for WOT. What we are going to do next is show you how to modify the TPS to eliminate this problem.
http://njsr.org/pics/albums/userpics/10757/TPS1.JPGThis is your TPS mounted on the drivers side front of the throttle body. You will need to remove the bonnet from the throttle body and rubber inlet off the MAF to remove it. It has 2 torx screws holding it on. Remove the wire clip and undo the 2 screws to remove. T-25 Torx.
http://njsr.org/pics/albums/userpics/10757/TPS2.JPG
http://njsr.org/pics/albums/userpics/10757/TPS3.JPGThis is the TPS off the throttle body.
http://njsr.org/pics/albums/userpics/10757/TPS4.JPG
Here on the back of the TPS is a position tab, it must be removed in order for you to complete this mod. You are going to be turning the TPS counterclockwise to advance the voltage setting. A file, dremel or in this case a razor knife is needed to remove the tab.
http://njsr.org/pics/albums/userpics/10757/TPS5.JPGHere again is the TPS showing the front side.
http://njsr.org/pics/albums/userpics/10757/TPS6.JPGYou see in the arrows in the picture. You need to elongate the holes towards the arrow points so you can advance it. You can use a drill bit, small rattail file, dremel etc to move the holes as close to the outer rim as you can and actually remove the rim.
http://njsr.org/pics/albums/userpics/10757/TPS7.JPGKinda like this picture. Front facing hole will elongated from its current position towards the top edge. The rear screw hole from its current position toward the bottom. This allows a counterclockwise resetting. One its done remount the TPS back onto the throttle body.
http://njsr.org/pics/albums/userpics/10757/TPS8.JPGHere you see a voltage measurement being taken. With the meter probes, take the positive probe and place it into the blue wire, negative probe into the black wire. Turn key to the on position. You want it to read .7-.8 volts in the idle setting, you loosen the TPS screws and move it counterclockwise until it reads .7-.8 volts and tighten.Don’t have a meter, you can just rotate it counterclockwise about ¼ the screw size.
http://njsr.org/pics/albums/userpics/10757/TPS9.JPG
In this picture we’ve moved the throttle to the WOT position to see that over 4.5 volts was achieved.
Once its set drive it for a short trip down the road. If its returns to idle with no problems, you’ve done it and could try to move it some more or leave it. If idle is effected move it back .1 volts or in case of no meter, just move it back very little and try again until idle is not effected. This will remove almost all the delay and get a jump earlier on the timing and fuel map. Caspers TPS enhancer is advertised to do this also, but it does not, it merely tell the OBD that at 75% throttle its at 100% so it still has this lag in it.
This is the basics and isn’t always the case. Some model years the voltage and idle is different. So with the probes you can get a base reading at idle position and then increase the base setting up to .4 volts more, but same basic principle.