Tps Q

[95GTV8]

Does TPS only effect idle issues, or does it effect overall drivability and horsepower etc?

 

[srothfuss]

It doesn't directly effect Horsepower, but it does effect driveability. "Flat Spots" in the resistor can cause hicups as you accelerate. Remember that the throttle blade is mechanically controlled. The sensor is only telling the computer how much gas you are giving the engine.

 

[95GTV8]

thank you.

 

[HISSIN50]

I would add that IMHO, the TPS adjustment is not quite as critical or finicky on an SN95 as on a fox. The SN seems to accomodate baseline changes better.

But that said, and like Steve said, checking it with a meter is always a good idea.

 

[RacEoHolic330]

Yea. I'm acutally having some TPS issues right now. I have it set at .99v at idle and it reads 4.66 at WOT, but when I put the throttle to the floor, my PMS only shows 98-99%, its pissing me off. Maybe I need a new TPS.

 

[HISSIN50]

Scott, I seem to recall that a fox should revert to WOT trim when the TPS sees 3.7 volts. Tom, Jrichker, et al will know for sure.

Good luck.

 

[Black1987Stang]

Scott, I seem to recall that a fox should revert to WOT trim when the TPS sees 3.7 volts. Tom, Jrichker, et al will know for sure.

Good luck.

I always wondered about that...

I was adjusting mine the other night and when it was at .95 at idle and at WOT it reads 4.66v...then i bumped it up to .98v and at WOT it went down to 4.59 i think it was, i thought it was weird when i bumped up to .98v the WOT voltage went down

I always feel a noticeable difference in throttle reponse when i adjust mine depending on how much it was off.


BTW Hissin and Jrichker if u see it, I fixed my crazy timing problem...the balancer was slipped like 30 degrees ....I put on the new Pioneer one(temporary) u mentioned and now it times like how it should Its been at 14 degrees this whole time, thinking about backing out down to about 12 or 13. But thanks for all ur help

 

[stang&2Birds]

Does TPS only effect idle issues, or does it effect overall drivability and horsepower etc?

Yea. I'm actually having some TPS issues right now. I have it set at .99v at idle and it reads 4.66 at WOT, but when I put the throttle to the floor, my PMS only shows 98-99%, its pissing me off. Maybe I need a new TPS.

The PMS is pretty dumb when it comes to the TPS. But, it doesn't make any real difference.

For all Mustangs with EFI from the factory, the TPS is zeroed out at start up. That *includes* the SD EEC-IV's. Most Stang EEC's set WOT at ~2.7 volts over the turn-on voltage of the TPS.

The main purpose of the TPS, in normal driving, is to add "accelerator pump" or the dash-pot function when there is a "quick" change in the throttle. The MAF (vacuum for SD) is slow to respond, and the O2's are super slow. So, the EEC uses the rate of change of the TPS along with the RPM to "estimate" the proper amount of additional/reduced fuel for the desired A/F ratio.

When the MAF (vacuum for SD) catches up, the EEC can _better estimate_ the desired injector pulse width for the desired A/F. However, it's really the O2's that determine a ton of stuff.

At WOT, the EEC uses the trim, the MAF output (vacuum & RPM for SD), and special WOT tables to calculate the fuel. Of course, those tables are often set to be on the _rich_ side in order to prevent pre-detonation. But, being too rich does cost HP. So, some tuners can adjust those WOT tables for your specific engine and set up and get you "a few more HP".

 

[HISSIN50]

BTW Hissin and Jrichker if u see it, I fixed my crazy timing problem...the balancer was slipped like 30 degrees ....I put on the new Pioneer one(temporary) u mentioned and now it times like how it should Its been at 14 degrees this whole time, thinking about backing out down to about 12 or 13. But thanks for all ur help

Glad to hear it is fixed and running well. I am sure Jrichker was much more helpful than I was, but thank you for the consideration. :SNSign: