Fox Quick Question 89 GT

[Aoneill5.0]

Been working on the 5.0 latley
Bought a month ago
A few sensors replaced, CTS,CTsender,TFI

anyway bought the ford code reader and
Now have 23 TPS.
KOEO generated that
But KOER gets 98 then engine stops

have a small erratic idle
So….

I ended up trying to test TPS
I get 5V reference at Green wire (with Black on gnd)
I get 3-4V on Red Signal wire and cannot get Volts to change with throttle movement

I even swapped to green wire and same thing.

Im guessing now the TPS is toast and setting my hard code?? 98??

hate just throwing parts at it.
But I’m sure it’s OEM TPS.

thanks

 

[General karthief]

This link: https://www.stangnet.com/mustang-fo...r-tps-to-0-99x-volts-is-not-necessary.825424/
Will tell you how to properly test the TPS, expand and read the links attached, that will help you trouble shoot it.
Thanks to jrichker an mustang5l5 for the info.
Not say'n you did it wrong but don't hurt to double check, you didn't say what the driveability issue were, if any.
I'm suspect about the sweep issue when moving the throttle, open it very slowly and the numbers should rise steady, if a zero pops up during the sweep then it's likely toasted.

 

[Aoneill5.0]

Thanks for the reply
I’ll look over it again and retest..

The car is running in open loop I figure due to the code 98 and I suspect the TPS for not allowing a closed loop scenario.

Surging idle and sometimes will stall in a parking lot with clutching.. at low RPM.

I will report back for sure!!!

 

[Mustang5L5]

I ended up trying to test TPS
I get 5V reference at Green wire (with Black on gnd)
I get 3-4V on Red Signal wire and cannot get Volts to change with throttle movement

I even swapped to green wire and same thing.

Black is your signal ground. Green is your output voltage from the TPS sensor.

You should be testing from green to black. The orange wire is your 5V ref. Check on the engine harness side as aftermarket TPS sensors can use different wire colors.

SO probe Green to black and you should have between 0.5-1.25V at idle. Manually sweet the throttle open and close and verify the voltage sweeps up to around 4V and back down. Code 23 is TPS voltage low, so it's likely under 0.5v, or was. It could also be an old code that's stored from the old sensor. I would clear codes and retest.


Code 98 points to a issue in the KOEO (engine off) codes that you need to correct first before it will let you proceed to running the KOER (engine running) codes.

 

[Aoneill5.0]

Hey General!! Andy here
In the garage testing TPS
Exact way you described

Orange wire 5.11V steady

Green wire 4.15V steady as well
(Even backed off idle screw and no change there

Black Grounded

Meter was connected to blk and green 4.15V
Throttle closed

Meter was connected to Blk and Red 5.11V Ref..

Just disconnected bat amd am waiting for 10 to clear CPU

then gonna check codes again.

Likely still get 23 TPS.

I’m Thinkin TPS is Gonzo

 

[General karthief]

It's possible the tps is bad but I think you're not testing correctly. You don't need to turn the adjusting screw, that is a different thing, re test per post #4

 

[Mustang5L5]

If he's getting 4 volts on black and green, then the sensor is either bad, or its installed correctly or bound up on the throttle post.

Remove the TPS and remeasure voltage between black and green. If it drops to around 1v then try reinstalling it

 

[Aoneill5.0]

I do believe I’m testing propery

All I was speaking about with the idle screw was backing it off in case it was way to higher and to see if my Signal V would drop
Which it didn’t.

Just manipulating the throttle was all I was doing..

I also pulled it off and made sure the TPS was all the way sprung closed(idle)
Still got 4+ V on it

I also used the 5v ref wire and preformed the same tests

Just in case the wiring was messed up..

We‘ve all seen that

Just ruling it out..

I do appreciate all the help tho.

This car is starting to drive me Nuts.

 

[Mustang5L5]

I think we are just doublechecking the testing process to verify.

From what i'm reading, it sounds like that TPS is junk then

 

[Aoneill5.0]

AGREED..

With your experience
Do you recommend Dealer Sensors or aftermarket to save a few bucks?

 

[nickyb]

I try and get motorcraft parts when available.

 

[Mustang5L5]

I also prefer Motorcraft or good, used OEM

Motorcraft CX1133 / E6AZ-9B989-C

​

 

[Aoneill5.0]

Ok. Sounds good..thank you