TPS Voltage?

I think you must just need to adjust it... try loosening the bolts and turning it slightly to see if you can change the voltage

Sometimes it is necessary to elongate the mounting holes.

Try this... Currently there is some dispute about setting it at .99 volts but anything less is probably OK. All you need is less than 1.0 volt at idle and more than 4.25 at Wide Open Throttle (WOT). You'll need a Digital Voltmeter (DVM) to do the job.

The Orange/White wire is the VREF 5 volts from the computer. You use the Dark Green/Lt green wire (TPS signal) and the Black/White wire (TPS ground) to set the TPS

Here’s a TPS tip I got from NoGo50

When you installed the sensor make sure you place it on the peg right and then tighten it down properly. Loosen the back screw a tiny bit so the sensor can pivot and loosen the front screw enough so you can move it just a little in very small increments. I wouldn’t try to adjust it using marks. Set it at .97v-.99v, the closer to .99v the better.

(copied from MustangMax, Glendale AZ)

1. Always adjust the TPS and Idle with the engine at operating temp. Dive it around for a bit if you can and get it nice and warm.

2. When you probe the leads of the TPS, do not use an engine ground, put the ground probe into the lead of the TPS. You should be connecting both meter probes to the TPS and not one to the TPS and the other to ground.

3. Always reset the computer whenever you adjust the TPS or clean/change any sensors. I just pull the battery lead for 10 minutes.

4. Check the procedure for your year, on my 90 I have to turn the idle screw until it just touches the tab, then insert a .010 feeler gauge and give it about one more turn. Then you adjust the TPS voltage to .98v, reset the computer. Start it up, if the idle is to low then turn the screw in until it is just right, then readjust the TPS voltage to .98v and reset the computer and start it up. The key is to adjust the TPS voltage and reset the computer whenever the idle screw is changed.

KBCobra95 said:

ok, I went out and trid again. I misread it was 4.75 at idle? Isn't that supposed to be WOT Voltage? BTW This is on my 89 5.0.

Click to expand...

You did misread. Look below and read again.

jrichker said:

All you need is less than 1.0 volt at idle and more than 4.25 at Wide Open Throttle (WOT)

Click to expand...

you must have checked the wrong wire , black goes to black and red on tester goes to green on TPS wires ....

check it "key on, ignition off"

rsw007 said:

check it "key on, ignition off"

Click to expand...

How do you pull that one off?

I think you mean Key-on, engine off.

hahaha

lol

yeah thats what i meant. lol worked to many hours this week.

Check the ground for the injector harness. I had a similar issue and had to connect a ground wire to the ACT sensor to get it working.
I did not trace the ground wires back to where it was loosing contact but it worked.

Edit: The ACT backfed the ground to the entire harness and the TPS sensor read correctly then.

Check the pins output from the TPS connector w/TPS disconnected w/DMM to ground, KOEO. You should have 0vdc at the Blk/Wht wire, 4.85-5.15vdc at the Org/Wht and 0vdc at the Dark Green/Light Green wire. If they chek out fine,....bad TPS , TPS needs replacement.

If the last pin check shows anything above 0vdc, need to do checks for wire shorts or...disconnect EGR Sensor to make sure it's not causing a short in the TPS circuit. My 2¢.

Always take resistance measurements with the circuit powered off.

Check the black/white wire resistance. Connect one ohmmeter lead to the black/white wire on the TPS and one lead to the negative post on the battery. You should see less than 1 ohm, more than that indicates a problem.

Clean the 10 pin salt & pepper shaker connectors.
.