Udjusting your TPS (Tuned Port Injection)


This is a very simple procedure, and there are really three methods of determining actual voltage.  You will need a very small Torx bit if you still use the factory bolts to retain the TPS to the Throttle Body.  I cheated and used bolts from a hardware store so that I could make quick adjustments using a standard screwdriver.


First, you need to locate the TPS if you don't already know where it is.  It is located on the right side (from sitting behind the steering wheel) of the Throttle Body.  See picture below.


Now that we have found it, lets determine what method is right for you.  My personal preference is to use a Scantool.  I feel this is the BEST way, since it is reading what the computer sees.  Just plug the Scantool into the ALDL connector and pull up the DATA list and look for TPS voltage.


Unfortunatly, not everybody has a Scantool.  There are two other methods, but both require a DMM (Digital Multi-Meter).


The second way, is to use a thin paperclip, or similar type of thin, conductive apparatus.  I use a paperclip in a bind, it seems to work well.  You will need to carfully insert the unfolded paperclip into the connector.  You will need to "tap" into the CENTER wire.  Its the BLUE wire.  Just slide it into the connector where the wire goes in at.  Push it in untill it bottoms out.  You may have to wiggle it some and see if it goes in further for a good contact.  Then simply hook the "positive" lead of the DMM to the paper clip and the "negative" lead to a good ground.  Turn the key "ON" and note the reading.



The last method still uses a DMM, but seems to be the most common among the "tech" articles that are out there.  You will need three jumper wires, with both ends stripped off.  Unplug the TPS sensor, and install a jumper wire from cavity "A" (the top one) of the TPS, to cavity "A" of the connector.  Do the same for cavity "C" (the bottom one).  Now, install a jumper wire from cavity "B" (the center) of the TPS, but do not put it in the connector, instead, hood the positive lead of the DMM to it, and hook the negative lead to a good ground and note the reading.





Hopefully, by now, you have figured out which one will work best for you.  Once you decide, you will need to round up the appropriate materials.  Once the initial reading is obtained, if it is incorrect, loosen the two mounting screws on the TPS and rotate it until the desired reading is obtained.  Once it is obtained, tighten the screws down, and re-check.  Do a few turns Wide Open Throttle and re-check.  Factory specs are: .54 Volts, +/- .075.  However, the best part of having an adjustable TPS is you don't have to stick with factory settings.  You can play around with it to get the best throttle response or track times.