Contour Enthusiasts Group Archives Forums Modifications Duratec Performance TPS MOD DONE !!

I finally got around to trying this out after WA2FAST initially brought up the idea he's done on Mustangs. I bought myself a multimeter @ Radio Shack a few days ago to test the voltage (around $25 Cdn.). First thing you gotta do is remove the plastic cover that says "Duratec" on it. (3 7mm screws). You'll see the TPS module on your side of the throttle body (assuming your standing in front of the car). You may want to disconnect the vacuum hose that's in the way from the accordian tube. You'll see 3 wires there connecting to the TPS that can be unclipped. Don't unclip them yet. Turn the ignition on so your dash lights are on but don't start the car. Take a safety pin and probe it into the white wire. Take another safety pin and probe it into the brown wire. Ignore the yellow wire. Take the voltage meter and touch the positive lead to the white safety pin and the negative lead to the brown pin. Note down the voltage - mine was at .91. Now unscrew the 2 screws holding the TPS to the TB enough that you can move the TPS - be careful the screws are soft. What you now need to do is move the TPS in such a way that it moves clockwise (ie. push down on the top right side of it) as much as it'll go then tighten the screws again and re-check the voltage. If yours is like mine the voltage will stay the same or go down. In order to allow more clockwise play, my next step was to completely remove the TPS by removing the 2 screws and unclipping the wire loom (where you were probing). I then drilled out some of the brass material that is where the screws went thru - it's not threaded so no worries here. I used a 1/4" metal bit. Upon re-install I was able to get the voltage up to only .935.

Now for impressions: I could only take the car for a 3 min. drive or so, but did notice improved tip-in. The weather's damp and cool here so I'll need to drive it again tomorrow to ensure it's not because of the weather that the car's taking off a bit quicker. I'll likely drill out the brass tube completely to get the voltage up, so stay tuned for further impressions ...

i think it has merit - keep up the work!

... had more of a chance to drive it today and the throttle is definitely touchier (I doubt I'd wanna go upto .98 as someone else said). I'm finding it a little more difficult than before to shift smoothly in 1st & 2nd. I had a chance to boot it a bit once (albeit not WOT) and there was a definite mid-range improvement (the 4 yr old in the back even made a go fast comment ). I'll have to drive it at the .935 voltage for a week or so and see then if I wanna experiment upwards a bit more to try and find a happy median ... for now I'm liking it. Oh, it revs quicker too!

the comments from the back seat are worth every blip of the throttle

Glad that you like what you have done so far LBVSVT!! Drill out the brass holes even more or completely out. Leave your car in the "on" position as you are setting it... you can watch the voltage on your meter as you move it around to set it... that makes it easier... when you are done setting it and tighten the screws down, flip the throttle plate a couple of times to make sure that it returns where you origionaly set it at. You won't do anything bad by reading the voltage while the car is on (not running) and moving the throttle plate... don't worry. Glad that you like it so far... I am going to do mine today, I have made time.

Along with me doing this mod, I am going to also make another TH fix piece for the summer since mine seems not to work nearly as well as it did in the winter. I am going to make another one with a slightly smaller hole.

Lou: You should also check the WOT voltage. It is possible to go too far with this mod. Never exceed .475 vdc at WOT. Personally, I don't like using the "piercing" method. It allows corrosion where the insulation has been pierced-bad news where road salt is used in winter. Easy enough to make up a jumper set and wire the voltmeter in series with the TPS signal wire. Pick up the ground at the battery.

Thanks Brad. I'll have to hook up the OBD-2 this weekend to get some #'s. I hear ya on the piercing of the TPS wires but I doubt rain or salt would ever make it up that far - wires do look a bit like swiss cheese though.

If this really made enough of a difference to the PCM, wouldn't the idle be raised? Basically, it seems like were fooling the PCM into "thinking" the TB shaft is rotated slightly. Maybe I'll play with the meter tonight and see what it says...

I thought so too - but at .935, the idle is the same, although it does appear to take a little longer to get there.

You can go to far... correct, but too far is over .99V at idle, when you rotate the throttle plate with the voltage meter plugged in, you will notice that the voltage goes up, not down, so WOT is over 2V if I can remember correctly, not down to .475V... that's about half of what it should be at, at idle.

Piercing the wires will not do anything bad at all. Salt, water, whatever... I live in MI and have done this mod on over 15 different cars, and oldest being 6 years ago and still no problems, corosion or anything bad at all. You can't see the holes and you won't hurt a thing!