Throttle Position Sensor

Ok, can anyone tell me what the voltage should be with closed throttle, in KOEO mode on the center pin (TP) of the throttle position sensor on a 93
2.3 liter ford ? Mine has 3.4 volts, the book says it should increase smoothly up to 3.4 and above. It'd be kind of hard for mine to do that, since it's starting out at 3.4, if the books correct.
I know the thing works like a volume control, but should the volume already be on ? Or should it be showing more like .01, or .999 volts with closed throttle ?
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Mhzjunkie

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On Mon, 12 Jun 2006 11:08:51 -0400, "Mhzjunkie"

In most Fords. the ECM provides a nominal 5 vdc to one leg of the TPS. The feedback voltage at idle usually ranges from a bit less than 0.5 vdc up to about 4-4.5 vdc as the throttle is opened. You want less than1.0 vdc at adle as that is usuall the point that the ECM believes your arer opening the throttle and starts to advance the timing and fuel curves along with everytihing else. In any case, it should rise very smoothly to it's max level whatever that may be occuring at about 3/4 throttle. After that, it should stay constant. The best way to check a TPS is disconnected w/an analog meter watching the needle very carefully as the throttle is opened and watching for any twitch or glitch in the resistance that may be indicated by movement of the needle.
The above is not meant to be exact data for your vehicle as it will vary from one to another depending on the exact calibration of a specific vehicle. I only hope to give you some idea of what you are looking to find.
Good luck Lugnut
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lugnut spewed out this bit, and i'll scatter a few bits myself

Ok, thanks man, you've pretty much cleared things up for me. The VREF supply is coming back though the feedback pin (TP) pretty much un-resisted. The response is smooth and does increase steadily, but I was pretty sure that 3.4 volts was to much for idle voltage on the TP pin. I'll change that thing out.
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Mhzjunkie wrote:

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wrote:

He is and 3.4 volts is way too high a reading at idle. As long as he is getting 5 volts and 0 volts on the other 2 pins his TPS is bad. Bob
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Bob spewed out this bit, and i'll scatter a few bits myself

Yeah, im pretty confident the things shot. Here's the same diagram as I have....
http://tinyurl.com/qmxxe
It's the center pin (TP) that has the 3.4 volts at idle. Anyway, I've went to far to back out of changing it now. Those two screws were a pain in the arse to get out.
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"Mhzjunkie" wrote

Did you use the correct Pozidrive bit, or just a Phillips that sorta fit?
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MasterBlaster spewed out this bit, and i'll scatter a few bits myself

I used a phillips bit that fit. Those should have been start-bit type of heads, if they where going to put so much thread locker on them.
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I dont think it's threadlock.. I think it's corrosion.
Same on my 95 taurus 3.0. 1 came out easy, other broke.
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Backyard Mechanic spewed out this bit, and i'll scatter a few bits myself

No corrosion on mine, BM, loads of thread-locker though, you can see it. Loctite looking stuff, real thick. I hack-sawed the heads off the screws, slipped the TPS off and filed flat spots on each side of the screws and used a small wrench to work them in and out until they were loose enough to get out.
Does the new TPS come with screws? I sort a doubt it, but the screws should be easy enough to locate. It might be awhile before I get around to actually going and buying a TPS. I know they don't cost all that much, but I got the car cheap and it's not the daily driver, so I'm only messing around with the thing for something to do right now.
The car runs better with the old TPS disconnected, the 3.4 volts is dropping back down to where it should be with it disconnected (haven't measured it, but im sure that's what's happening). Keeps a steady, and smoother idle. With it connected the idle was up and down and a slight miss and skip here and there.
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Backyard Mechanic wrote:

Nope, it's blue Loctite. Ford has used it on their TPSs for years. I've got a 2 foot long Pozidrive screwdriver that I use almost exclusively on TPS screws. The flex of the shaft helps pop them loose without snapping the screw. A little heat on the housing from a butane micro torch helps too, they back right out.
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