I set my TPS to 0.54 Volts. WOT only gave like 3.75 Volt. Does this mean my TPS is bad or Do I need to set the TPS to 0.47 and the upper number will go up? The voltage changed from 0.54 through 3.75 without stumbling.

Exactly how does a bad TPS act?

Thanks,
Scott

 

It means you may not have it adjusted properly. The adjustable style TPS is a tad tricky until you get used to it. Snug one of the two bolts just enough so that it'll hold it in place, but you can still rotate the TPS. Play with it and see what happens to your voltage. Now snug the OTHER one, and losen the first one. Play some more. You'll see that the voltage changes will be a bit different.

I found that by keeping one snug, I could adjust idle voltage without having much impact on WOT voltage, and vise versa. If you screw around you will probably be able to get your .54 and get the proper WOT voltage.

 

Here is an idea. I modified the TPS to get both the .54V and 3.94V. You'll need to cut out the rear of the upper slot on the TPS mounting holes. Here is an illustration:



I fumbled with the TPS before to try to get as close to 4V but you'll either get the idle setting or the WOT setting. With this small mod you'll be able to get closer to 5V than without it. Please notice that 4V is reference voltage and that when you set the TPS you'll only get 4.94V max at WOT. It takes a little time to set it but it will give you what you want. As far as any power gains at WOT goes I don't know if there is any.

Now back to the original question of when a TPS goes bad. If you use an analog voltmeter to test it, a good TPS will show a steady climb in voltage. Otherwise if it is bad it will stumble around.

-Ozzy

Correction: changed voltage values

 

I got way over 4 volts without cutting my TPS. I think my WOT is around 4.5 volts

 

What should the WOT volts be? I too get over 4 volts but not quite as high as 4.5. More like 4.1-4.22.
My Idle is set @ .55(that's as close as I can get it)
I am using Moates software to read the voltage is that OK? Or should I actually use a voltmeter? I figure if that's what the ECU is reading.

On a side not...when my TPS was set .39 I never saw over 3.9 at WOT...and it makes a difference.

 

Couple question for both poncho and abcx...

Are you manually opening the TB or pressing the gas pedal?

Floormats and carpet can interfere with WOT...as well as a stretched throttle cable.

 

pressing the gas pedal. I will look to see if the blades are completely open when the gas pedal is floored.

But I am pretty sure that when I floor it inside there is no travel left on the throttle body. I will check.

Off to the track tonight. Hope to see some good MPH with my new heads and headers. I won't be taking my hoosiers so my ets won't be the best because my street tires can't hook for ****!

Any estimates? Before heads, headers and SDPC TPI base I went 96+ MPH.

See the rest of my mods in my sig.

 

Sorry guys I meat to say 5V reference, and that I get 4.94V with the moded TPS. I was thinking off the top of my head.

On the topic about the gas pedal not reaching WOT, I did a little mod to my linkage. If you look at the cable where it goes through the hole on the pedal arm under the dash, there is about 1/2" of slack. I used a 3/8" piece of cooper tubbing, cut a slit along the side and flared one end. Pull the cable toward the dash and insert the tubbing around the cable with the flared end toward the end of the cable. Crimp the tubbing so it doesn't come out and you are done. This moves the gas pedal away from the floor and gives you WOT capability without it hitting the mat.
I'll post a closeup picture in a bit.

-Ozzy

 

Here is the small piece of tubing:



and here is a closeup, a little blurry but it shows the end of the cable where I placed the tubing. To keep the tubing from speading I used a plastic tie.



-Ozzy

 

just another thought. As long as you're getting 4 volts or close to it, the computer will recognize it as WOT. I think anything above 3.6 or 3.7 volts is recognized as WOT by the computer.