Detailed information about setting your throttle position sensor voltage
I want to tune my Throttle position sensor and I was wondering what kind of volt meter you need, because I have a voltage multimeter and I'm not sure what setting I should have it on, or if it'll even work. Can someone please explain?
I need help too because Im not sure what Im adjusting. Is the whole TPS supposed to move? Is it just that round part in the middle? Mine looks like its all one piece. My volts are only at like .60v... I am confused
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Cardinal Red '88 GT 5 speed, Cobra Upper/Lower, Dynomax complete Super-Turbo cat-back system, Turbo Coupe Rear 10" discs, 3:73 gears, SN95 Master Cylinder, Summit Racing adjustable proportioning valve, Spec Stage II kevlar clutch, steeda adjustable cable/quadrant, 73mm front calipers, P.A. Performance 130 amp alternator, 99 Contour Electric Dual Fans, Battery relocated, rebuilt 91 T-5, Mass Air conversion
Last edited by Stangboy5666; 09-20-2004 at 11:45 PM.
Let me explain what the throttle position sensor does and how it could tell the computer any information.
To get a better sense, remove the TP sensor from the throttle body completely. You will see an end sticking out simliar to a flat screwdriver. That will fit into the throttle position sensor. As you push the throttle , it turns. When it turns it changes the voltage that the sensor reports. So if your sensor is set too high, it reports that the throttle is somewhat pressed (to an a small extent but it is still incorrect). When it shows it higher, it tells the computer "Im at this point of the Wide open throttle cycle." Imagine the sensor is reporting equivelant to the pedal being pressed 10% down, but it's actually at 5%. What does it do when it reads higher? It dumps more fuel because you need more fuel to accellerate. Or it could read the other way around. You could be at Wide open throttle (the pedal is being pressed to the floor) but it only reads you are around 3/4 to the floor. You are telling the computer where you are at and it adjusts how much fuel to add (simply put).
When you adjust the idle screw you are opening/closing the throttle butterfly more. Well guess what is sitting on top of the the butterfly? Your TP sensor. So when you adjust the idle screw , you adjust the voltage of the TP sensor because it turns it more one direction that it was already calibrated at. So when you adjust one, you should adjust the other, making sure though the TP sensor is always set last!
Ok. First of all you set the TPS when the car is off and the keys are up (radio comes on). Make sure your voltage meter is DIGITAL , not the sweeping kind. Set it to DC voltage reading, not AC or anything else. Push a sewing needle through the center of the green wire coming off of the TP sensor.You are going to be hooking up the red (positive) wire to the needle that you pushed through. I like to put the black wire (ground) up the the bolt that holds the TP sensor onto the throttle body. Ok by now you know what wire needs to checked and where to hook up your ground. Read your meter. It can read anywhere from 0.00v to 3.00 depending on how messed up it is. As described earlier the meter determines the voltage by how much the butterfly of the throttle body is opened because it rides directly on top. So we must turn the throttle position sensor to match the voltage we need (it is a small fraction of a turn but it still moves some). You are trying to set it at 0.98 volts !
To turn the throttle position sensor we need to loosen the two bolts that hold it. This allows us to turn the sensor clockwise or counter clockwise. To figure out which way it needs to go you must know where it currently is. If it's too high, you need to lower it. Turn it one direction, if it goes even higher or lower than you need you must turn it the other direction. It can be slightly tedious , turning and checking the voltage. It helps to have a buddy hold the wires on the correct spot and you turn it as necessary so you can read it in realtime. Once you have it set at the right spot tighten the bolts down. Recheck your voltage to make sure it didn't move. If the voltage changed loosen the bolts slightly and try to nudge the sensor so you can still move it but it won't move when you tighten it.
After that you are set. You can start charging people good money to tune their TPS.
Reading this post made me realize that when it comes time to let the EPA
search your exhaust, the TPS is something to retune, probably to a lower
setting. The higher voltage richens the mixture earlier. I barely passed
the sniffer last time (3 tries), but never thought to turn it back to a lower
setting.
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1992 Deep Emerald Green Mustang GT Hatch, 5 speed, 2.73s, Mac fenderwell cold air intake, '93 Cobra MAF, Mac 70mm throttle body & spacer, Explorer intakes, Mac unequal headers & offroad pipe, Magnaflow catback, Walbro 110lph fuel pump, Jet adjustable FPR, MSD Blaster coil, Accel 8mm wires, FRPP aluminum quadrant, UPR firewall adjuster, stock cable, Granatelli upper control arms.
Waiting to go on: Granatelli lower control arms, and GT40 Iron heads!
Its really easy 2 do thanks to ghost dog when he explained it 2 me in my terms and yes the whole thing moves not just the middle of it sorry the hole black peice
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87 mustang gt 5.0 5 speed,Flowmaster,Bored .30 over ,BBK Shorty Headers,Steeda short thow,New engine fully rebuild pure carb..
i know a guy who runs his at . 600 cuse his 95 is way rich at .98 and yes he had it everywere to find out why but his car is realy fussy... more than most iv seen so there is no 100% right or wrong. mine likes .900 go figure.
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maybe im doin something wrong, but i cant figure out how to adjust it! i loosen the 2 screws, but to me it seems like its non adjustable! is it just me and im doing something wrong here, or is there somethin else i need to do or what????
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91 notch, 11.5:1 331, victor jr. heads, victor efi manifold, trick flow stage 3 cam. 401 RWHP through AOD hitting the stock rev limiter at 6200. (not including an extra 200hp motivation from a nitrous works system):-D
don't forget to check the resistance on the meter leads...if you've got high resistance in you leads it could give you a false reading. good continuity should be like .01 or .02 ohms.
You can also adjust the TPS voltage by adjusting the butterfly screw underneath the throttle body. If I recall it is a 12 mm bolt. I adjusted my stock TPS about 20 times. Come to find out. I replaced my TPS (new from autozone for $30) and I had to readjust everything again.
I run mine close to 1 volt but I believe it is set at .985 or so.
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'89 LX 5.0 Hatchback
For accuracy on your track times. GO TO THE TRACK!
8.1 with 5spd et streets
AOD all motor 8.8@78 mph street tires
125 shot nitous 7.51@91 mph street tires
Does anyone know what the initial throttle opening setting is supposed to be?
I have searched everywhere and even ford cant tell me----seems that that is rather a rather crucial setting when initially setting up your intake system
I have three throttle bodies and they are all set different--there must be a initial setting????HMMMMMM?
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Red 86 GT Convert-K&N, heads shaved .020", ford racin wires,solid quadrant, firewall adjuster, Hurst shifter, black 92 interior, poly bushings, 2 1/2 flowmasters w/ maxflow cats
Detailed information about setting your throttle position sensor voltage 
thanks to ghost dog when he explained it 2 me in my terms 
Initial throttle gap? 
