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
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.
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
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
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.
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
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
Nope, it's blue Loctite. Ford has used it on their TPSs for years. I've got a
long Pozidrive screwdriver that I use almost exclusively on TPS screws. The flex
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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