TPS sensor

slow5.0gt · Dec 29, 2006

Im having trouble adjusting the TPS sensor to .99 volts when I adjusted it months ago i was able to hit .99 however when I checked the voltage lately to find that surging idle I found that it was instead at 1.13 volts the closest I could get was 1.05 it helped with the idle a bit but still only happens when its cold warm poses almost no problem.
However the main question is will 1.05 volts in tps really affect me that much or is the margin of error really only .98-1.01 volts?

seijirou · Dec 29, 2006

slow5.0gt said:
Im having trouble adjusting the TPS sensor to .99 volts when I adjusted it months ago i was able to hit .99 however when I checked the voltage lately to find that surging idle I found that it was instead at 1.13 volts the closest I could get was 1.05 it helped with the idle a bit but still only happens when its cold warm poses almost no problem.
However the main question is will 1.05 volts in tps really affect me that much or is the margin of error really only .98-1.01 volts?

From what I understand, the tps voltage is "zero'd out" at startup, so that the specific voltage doesn't matter, it's just supposed to be around the 1 volt range. This makes me wonder what happens if you're in the habit of goosing the throttle while starting the car however.

Some people swear by .99 volts. The first time I ever checked mine it was 1.1x volts and the car ran great so

seijirou · Dec 29, 2006

Oh, if you want to get more adjustment out of it, get a drill bit that is ever so slightly larger than the current tps screw holes, and open them up. That should give you the play you need

93gtmustang · Dec 29, 2006

Readings will change with temperatures. You can carefully bore out the holes for the screws so that you have more adjustment. That should get you where you want. Have you adjusted your idle recently? If you raised the idle higher, that would be one reason why you can't get back to .99.
The TPS reading will change if you set it when the engine is cold and then check it when it is hot, resulting in a higher reading when it's hot. Try it sometime. It will vary.
I try to set mine when the car is warmed up. I also set it to about .98 to .985. I read in a book about modifying 5.0's, that setting the tps anywhere above .93 doesn't do anything but cause a rich fuel condition. Take it for what it's worth . Do what works best for your car.
Like I said, I set mine at .98 to .985. That way, with temperature changes, it doesn't go above .99. I personally feel that there won't be any difference between setting at .98 and .99. You don't have to be that close to 1.0.
Hope this helps

93gtmustang · Dec 29, 2006

Here is a post on setting the TPS.

Let me explain what the throttle position sensor does and how it could tell the computer any information.

To get a better sense, remove the TP sensor from the throttle body completely. You will see an end sticking out simliar to a flat screwdriver. That will fit into the throttle position sensor. As you push the throttle , it turns. When it turns it changes the voltage that the sensor reports. So if your sensor is set too high, it reports that the throttle is somewhat pressed (to an a small extent but it is still incorrect). When it shows it higher, it tells the computer "Im at this point of the Wide open throttle cycle." Imagine the sensor is reporting equivelant to the pedal being pressed 10% down, but it's actually at 5%. What does it do when it reads higher? It dumps more fuel because you need more fuel to accellerate. Or it could read the other way around. You could be at Wide open throttle (the pedal is being pressed to the floor) but it only reads you are around 3/4 to the floor. You are telling the computer where you are at and it adjusts how much fuel to add (simply put).

When you adjust the idle screw you are opening/closing the throttle butterfly more. Well guess what is sitting on top of the the butterfly? Your TP sensor. So when you adjust the idle screw , you adjust the voltage of the TP sensor because it turns it more one direction that it was already calibrated at. So when you adjust one, you should adjust the other, making sure though the TP sensor is always set last!

Ok. First of all you set the TPS when the car is off and the keys are up (radio comes on). Make sure your voltage meter is DIGITAL , not the sweeping kind. Set it to DC voltage reading, not AC or anything else. Push a sewing needle through the center of the green wire coming off of the TP sensor.You are going to be hooking up the red (positive) wire to the needle that you pushed through. I like to put the black wire (ground) up the the bolt that holds the TP sensor onto the throttle body. Ok by now you know what wire needs to checked and where to hook up your ground. Read your meter. It can read anywhere from 0.00v to 3.00 depending on how messed up it is. As described earlier the meter determines the voltage by how much the butterfly of the throttle body is opened because it rides directly on top. So we must turn the throttle position sensor to match the voltage we need (it is a small fraction of a turn but it still moves some). You are trying to set it at 0.98 volts !

To turn the throttle position sensor we need to loosen the two bolts that hold it. This allows us to turn the sensor clockwise or counter clockwise. To figure out which way it needs to go you must know where it currently is. If it's too high, you need to lower it. Turn it one direction, if it goes even higher or lower than you need you must turn it the other direction. It can be slightly tedious , turning and checking the voltage. It helps to have a buddy hold the wires on the correct spot and you turn it as necessary so you can read it in realtime. Once you have it set at the right spot tighten the bolts down. Recheck your voltage to make sure it didn't move. If the voltage changed loosen the bolts slightly and try to nudge the sensor so you can still move it but it won't move when you tighten it.

After that you are set. You can start charging people good money to tune their TPS.

93gtmustang · Dec 29, 2006

I forgot to mention. Make sure your black wire on your voltage meter is to a good ground source. I can get different readings on mine if I don't have a good ground location.

stang&2Birds · Dec 29, 2006

93gtmustang said:
Here is a post on setting the TPS.

Yea, BFD! You know that you can read on the net how the moon landing was all fake!

Here is **MY** TPS FAQ!
http://www.veryuseful.com/mustang/tech/engine/Mustang-TPS-FAQ.html
Quick Summary:
You never have to adjust a Ford TPS unit on a Ford TB (that has the idle set to spec)- NEVER!!

For people that adjust their idle higher than spec to keep their engine running with their setup, or people that use a NON-Ford TPS, then they may have to adapt the TPS unit (by making slots) so that it reads from ~0.6v to ~1.1v at idle.
...

READ IT!
BTW: I design the type of stuff for a living!

Like someone else said, the "TPS" voltage will VARY with temp and battery charge. Actually, the VREF AND the mechanical tolerances will VARY with temp. VERY VERY VERY basic stuff!! Many high school students even learn that!

seijirou · Dec 29, 2006

stang&2Birds said:
Yea, BFD! You know that you can read on the net how the moon landing was all fake!

Here is **MY** TPS FAQ!
http://www.veryuseful.com/mustang/tech/engine/Mustang-TPS-FAQ.html
Quick Summary:
You never have to adjust a Ford TPS unit on a Ford TB (that has the idle set to spec)- NEVER!!

For people that adjust their idle higher than spec to keep their engine running with their setup, or people that use a NON-Ford TPS, then they may have to adapt the TPS unit (by making slots) so that it reads from ~0.6v to ~1.1v at idle.
...

READ IT!
BTW: I design the type of stuff for a living!

Like someone else said, the "TPS" voltage will VARY with temp and battery charge. Actually, the VREF AND the mechanical tolerances will VARY with temp. VERY VERY VERY basic stuff!! Many high school students even learn that!

So if I'm the kind of person who's in the habit of pumping the gas pedal while turning the car on/starting the car...being that the TPS is 0'd out.

I could really be screwing with how she's gonna run couldn't I.

HISSIN50 · Dec 29, 2006

seijirou said:
So if I'm the kind of person who's in the habit of pumping the gas pedal while turning the car on/starting the car...being that the TPS is 0'd out.

I could really be screwing with how she's gonna run couldn't I.

IMHO, as it ratchets, it outsmarts you. Now you could cause an issue if hitting ~3.71 Volts (WOT per the puter) as it will shut down the injectors. But that is by design.

Way back when, I'd pump the pedal on EFI stuff but have managed to stop.
Oh, but now I do have to remember to do it on the old carbed stuff.

slow5.0gt · Dec 29, 2006

I have to pump the pedle upon startup or the car will die on me i remember when I first tested it I got .99 at cold but when I tested it the 2nd time and got the higher number it was after it was warmed up so I might just not be far off after all.

stang&2Birds · Dec 29, 2006

HISSIN50 said:
IMHO, as it ratchets, it outsmarts you. Now you could cause an issue if hitting ~3.71 Volts (WOT per the puter) as it will shut down the injectors. But that is by design.

Yup. The EEC will adjust the "zero point" of the TPS over time. But, pumping the pedal at start-up will confuse the EEC for "a while".

The "big" thing that the TPS does in normal operation is "acceleration pump" and "dash-pot". During start-up, the engine will be running rich. So, there's a "decent" chance that the engine "could" still run even-though the "acceleration pump" and "dash-pot" functions aren't working correctly for a while.

stang&2Birds · Dec 29, 2006

slow5.0gt said:
I have to pump the pedle upon startup or the car will die on me i remember when I first tested it I got .99 at cold but when I tested it the 2nd time and got the higher number it was after it was warmed up so I might just not be far off after all.

You have a C&L. That's bad enough! But, then you have a C&L with a scaled-output without a chip. You're lucky the car runs at all.

93gtmustang · Dec 29, 2006

The original post by slow5.0gt was about adjusting his TPS.
I realize factory set components do not need adjustment.
He's adjusting his idle and running a "non-Ford" 70mm throttle body in which he wants to adjust his TPS.

Originally Posted by stang&2Birds
Yea, BFD! You know that you can read on the net how the moon landing was all fake!

I'm just giving slow5.0gt information that I've read and passing it on. Every article that I've read, has been very similair to the one I posted.

Originally Posted by stang&2Birds
You have a C&L. That's bad enough! But, then you have a C&L with a scaled-output without a chip. You're lucky the car runs at all.

My car runs great with a C&L MAF!!

Originally Posted by stang&2Birds
READ IT!
BTW: I design the type of stuff for a living!

Do work for the Ford Motor Company?

Originally Posted by stang&2Birds
Like someone else said, the "TPS" voltage will VARY with temp and battery charge. Actually, the VREF AND the mechanical tolerances will VARY with temp. VERY VERY VERY basic stuff!! Many high school students even learn that!

A VERY, VERY, VERY ANGRY PERSON YOU ARE!!!

slow5.0gt · Dec 30, 2006

stang&2Birds said:
You have a C&L. That's bad enough! But, then you have a C&L with a scaled-output without a chip. You're lucky the car runs at all.

Zoommm!.... Scaled output?

vristang · Dec 30, 2006

93gtmustang said:
The original post by slow5.0gt was about adjusting his TPS.
I realize factory set components do not need adjustment.
He's adjusting his idle and running a "non-Ford" 70mm throttle body in which he wants to adjust his TPS.
!

It makes no difference whether the TB is factory Ford or Aftermarket. The TPS is the same and the computer uses the signal the same.

From what I have gathered going through the Ford document (the GUFB), the tps signal is used as a differential more than an absolute.
WOT is set based on the lowest idle tps ouptut seen. That low point can be adjusted at any time the car is running. It doesn't 'set' at start up.
The other major use I have seen is during accel/decel. Under these conditions the rate at which the tps signal is changing is used to gage how quickly fuel and timing need to be advanced.

If I am correct...
The only absolute use of the tps signal is to determine if the signal voltage is out of range?
IIRC, the range is .6-1.1v???

I am guessing that the 'scaled output' comment made by Joe, is in regards to how the aftermarket MAF meters are 'calibrated' to an injector size?
Basically, what they do is modify the output voltage of the MAF in relation to the change in injector size.
Can you clarify Joe?

The tps always seems to stir emotions
I don't get it

:Word:

jrichker · Dec 30, 2006

Some people have odd passions...

saleen409 · Jan 1, 2007

slow5.0GT, check your email.........

vristang · Jan 1, 2007

jrichker said:
Some people have odd passions...

JR...

That could be said of most of us

:Word:
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