Wierd TPS setting.......

[doublenotch]

I recently swapped to a used 70mm Throttle body and it did not have a TPS on it. I installed the TPS from my old throttle body and went to set it like instructed from this site. Key on engine off and back probing the wires I get 4.5 volts at idle and .3 volts at WOT. Isnt it supose to be the other way. I'm thinking I installed it wrong but I cant figure it out. Any help would be appreciated.

 

[daddystang]

Are you using the green and black wire to get your reading?

 

[jrichker]

No info about your car's model year, EFI or carb, no mods listed. Makes it hard to troubleshoot when we don't know what you have.

Therefore, no clue as to which wiring diagram you need. The wiring and wire colors changed several times between 79 & 95.

That's why it is a good idea to use the sig under the user control panel (User CP) option. It allows you to post your car year & mods, which help greatly when troubleshooting things. No, it is not there for us to snoop and see any "Secrets" you have hidden away under the hood. Be a good stangnetter and update you sig for future reference & don't keep us guessing.

 

[doublenotch]

Thanks for the replies. I updated my sig Jrichker. Makes sense after I read your post. I'm using the black and white wire for ground and out of the other two wires I'm using the one that varies voltage when the throttle is moved, it has a white stripe to it. It is hard to tell the colors because the engine harness is old and faded. I tried the other wire and it is just 5 volts all the time which I imagine is my 5 volt reference, the one not to use. Reading alldata had a specific way to install the TPS. It said to install it and move it 10 to 20 degrees to line up with the bolt holes

 

[Mustang5L5]

More than likely you are reading the reference voltage. The TPS gets about 4.5 volts power, and then the other wire is the signal wire coming back from the TPS.

The black wire is ground that is correct.

Once you find the right wire, just set it UNDER 1.0 volt. You don't need to be precise, you just want the TPS in range so that it will be around 1 at idle and over 4.5 will signal WOT to the computer. Over 1 at idle will trigger WOT voltage way too soon

Most say that you should try to set it to .97 volts, but the computer takes a base reading at each startip and zeros it out, so this number is not very important. Just keepint the range correct is

 

[vristang]

Reading alldata had a specific way to install the TPS. It said to install it and move it 10 to 20 degrees to line up with the bolt holes

Curious...

Would you mind doing a 'copy-paste' on that procedure so we can take a look?

 

[cjnecessary]

Did I miss the carbed car with a t.b.?

 

[Mustang5L5]

Where do you see carbed??

 

[cjnecessary]

just wondering why it was there was a question about it being carb'd or f/i when he is talking about t/b's

 

[doublenotch]

Curious...

Would you mind doing a 'copy-paste' on that procedure so we can take a look?

Service and Repair
Notes

Throttle Body






REMOVAL


Disconnect Throttle Position (TP) sensor wiring connector.
Remove TP sensor retaining screws and sensor.
INSTALLATION


Install bushing from old sensor to new sensor.
IMPORTANT: The bushing must be installed with the larger diameter facing outward.

Install TP sensor on throttle shaft and rotate sensor 10-20°counterclockwise to align screw holes. Install retaining screws. Torque to 11-16 in lbs (1.2-1.8 Nm) .
Cycle throttle to wide open and release. It should go to wide open throttle and return with no interference.
Connect the TP sensor wiring connector.










© 2007 ALLDATA LLC. All rights reserved.

 

[doublenotch]

More than likely you are reading the reference voltage. The TPS gets about 4.5 volts power, and then the other wire is the signal wire coming back from the TPS.

The black wire is ground that is correct.

Once you find the right wire, just set it UNDER 1.0 volt. You don't need to be precise, you just want the TPS in range so that it will be around 1 at idle and over 4.5 will signal WOT to the computer. Over 1 at idle will trigger WOT voltage way too soon

Most say that you should try to set it to .97 volts, but the computer takes a base reading at each startip and zeros it out, so this number is not very important. Just keepint the range correct is

If I was reading reference voltage it would stay at 5 volts, not change when I move the throttle. I have 4.5 volts at idle and gradually goes down to .3 volts as the throttle body moves to WOT. Therefore I can not set anything to 1 volt at idle. Thanks for the quick replies!!