I noticed that quite often my car idles high and a little irradically. Ocassionally throwing a code for low TPS voltage. I was fiddling with the wires to the TPS and the idle will jump around somewhat.
Is it common for the pigtail to the TPS to short out? The screws for the TPS are tight and it is plugged in all the way.
One of the things I noticed was that the wiring is pretty tiny and delicate looking compared to my previous Mustangs.

 

I would not say it is common for the TPS wiring to be an issue. Maybe you need to replace the pigtail.

 

Thread hi-jack, similar question:
After swapping in a good used Holley 52mm the car had a light for the same thing - low TPS voltage.
My friend has a scanner and it read .2v in idle position. Plugged back onto my stock tb - read .66v
So he opened the screw holes to allow rotation of the TPS and got a .50v reading. Car runs fine, light stays off.
HOWEVER:
During a few WOT romps, at about 5,000 rpm the motor falls flat - if I lift the pedal a hair, it revs and takes off.
If I almost floor it from idles the car rips to 7,000 and shifts like before.
If I purposely stomp the pedal - the motor falls flat until I lift.

Could this be the opposite end of the TPS @ WOT not getting any volts so it stops calling for fuel? How many volts should it read up there?
Why no check engine light?

 

Did you test the voltage at WOT? I answered your post yesterday.Did you check to see if the butterflies are opening too far? I believe anything under 5v is acceptable.Idle should be .69v..I believe...Try a search,I know I found it there a while ago.

 

thanks-
no, need to get to my friend with his reader for volts.
butterflies are at a perfect 90 degrees from idle when WOT = straight.
Idle was .66 stock - best we could get without ruining the holes was .50 at idle.
Would I be looking for .xxv all through rotation until it hits WOT then a voltage drop? That would cause a bog from lack of fuel?
Suprised it doesn't give a code since TPS is at 100% and if the voltages is below required - like it did at idle...

 

if you disconnect and reconnect often the pigtail will stretch.

meaning: look inside the pigtail where it makes the connections. if you can see where the metal is pressed together in the shape of a closed C and there's space in there, you can close the gap by removing the ends from the harness and squeezing them together.

i had this issue with my ox sensors on a mustang.

 

The PCM will accept any closed throttle voltage from 0.20V to 0.90V. It will set that as the baseline = 0% TPP. If the closed throttle voltage drops below 0.20V, the code will set.

When you are checking the voltage, slowly rotate the throttle blades from fully closed to fully open. The voltage should increase smoothly and uniformly, hitting about 4V more than the closed throttle voltage at WOT. There should be no voltage spikes or dropouts as you open the blades. If the TPS voltage exceeds 4.90V at any time, you would get a "TPS high voltage" code. The PCM prorates the TPP% from the baseline voltage to the reported voltage as the throttle opens.

 

Injuneer - thant's the detail i was looking for - thanks
reading other related searches I'm finding 2 other common WOT and high end bog, power loss causes I'll look at if the TPS checks out to your specs.
1. fuel pressure regulator - mine is aftermarket - could be defective
2. injectors - 1 guy had identical issue but never posted TPS readings
He put in new injectors and cured the high rpm, WOT bog.

 

An analog voltmeter is good for noobs to check TPS's. You want a nice, smooth sweep to almost 5V.

I'll check the connections on my TPS today on my lunch break. I have noticed that ery could of days my idle creeps up to 1100 or so, and I need to reset the IAC. I think that the IAC is not the problem though. I think my TPS is shorting ocassionally, causing the ECM to send the IAC on a wild goose chase.

 

I closed up the female connectors on the pigtail a little bit and it seems to have taken care of the problem.

Thanks all!