I just changed my TB and want to adjust the TPS but it doesnt seem possible to do it like I have read on fox body cars. Is it possible to adjust on our cars and if so how.
I've never heard of being able to adjust the TPS (in essence how the computer interprets the voltage on it) without a chip or a custom tune. If there is a way, it would be nice to have the option of doing it.
I was told on this forum that the Throttle Position Sensor can be adjusted with a volt meter and by loosening the screws and moving it until the voltmeter reads .997-.999 with the key in the on position on fox body cars.This however does not work on 1994-95 cars. I want to know if there is a way on the 94-95 cars?
first start your engine and get it to normal operating temp and then follow these instructions.THEY MUST BE FOLLOWED EXACTLY IN THIS ORDER....
1.with the key off,disconnect your idle air bypass.(the iab is located right next to the tps on the throttle body)
2.start the engine with the IAB disconnected.(if it wont idle keep turning the idle set screw until it will without the iab connected,you may need a longer screw. )
3.with the engine running,set the idle to the desired rpm. (i like to set mine to 850-900 rpm)
4.turn the engine off and then turn the key to the run position without starting it.(koeo)
5.locate the 3 wires going to the tps,measure the voltage between the top wire and the center wire on the plug.it should be the gray with red stripe and gray with white stripe.***i just poke a hole through the wires with the probe from the volt meter. that way you can use your hands for adjusting the tps..MAKE SURE YOU PUT SOME SILICONE SEALANT OR RTV OVER THE HOLES WHEN YOUR DONE. *** (ford used different color wires on different cars)
6.adjust the tps until it reads between .96 and .98 (you will probably need to drill out the holes in the tps so it will move)
7.turn off the key and reconnect the iab. (idle air bypass)
8.disconnect the negative battery terminal for 5 min,step on the brakes and turn the lights on while the battery is disconnected.
9.reconnect the battery
you should be good to go..this usually fixes the annoying surging and driveability issues from installing an aftermarket cam.
I've always been told that the 94-95 TPS is pointless to adjust because the computer resets back to factory settings. Ask the question in the EEC forum and see what kind of response you get.
the eec does adjust to settings that are "out of range"..setting the tps voltage with the iac disconnected basically bypasses the the use of the iac..(wich many times is the culprit of idle issues and surging after modifications)..the eec can NOT adjust the voltage coming back from the tps..instead it will learn the voltage and adjust accordingly..your idle will stay where you set it.
It's pointless for the reason that's already been explained twice in this thread...the computer takes whatever voltage it sees at startup and uses it as its baseline. There's no reason for a TPS installed properly to be out of range so if you find you actually DO need to adjust it then you have a problem with the TPS itself or the TB it's attached to. The short-bus riders who tell you there's a performance benefit from setting your TPS to 0.9999999999999777799999999787999v are the same ones who think the hood blanket is a fire-suppression device.
It is pointless because (from what I've read) the computer will zero it out everytime no matter how it is set. Regardless of the starting voltage, the newer computer is able to interpret the full sweep of the throttle. I have a fox throttle body conversion on my car, but I was told to not worry about setting it, and so far so good.
And for the guy who's sharing the IAC info, what does that have to do with setting TPS voltage?
Look,nobody is telling you that this procedure must be done...If you dont like it or agree with it DONT DO IT!!!..The procedure came directly from frpp tech support..I think the guys over there know what they are talking about, after all the eec was designed by ford..this procedure works,it works well and i have used it on several sn95's with good results.
[/QUOTE=And for the guy who's sharing the IAC info, what does that have to do with setting TPS voltage?[/QUOTE]
This is the only tps voltage adjustment that i have ever heard of..Most of the time if you are setting your tps voltage you are having an idle issue..The idle set procedure is an entire process and that process happens to include the disconnection of the iac..The problem is that not everybody has the money to buy a custom tune to correct idle issues..Most people have to do modifications in small steps,and this is a bandaid for setting the idle until you can have a custom program set up for your car.
MFE before you go claiming that its pointless, have you ever actually tried it on a sn95? Im not trying to insult your intelligence,however this does work for correcting idle issues usually ascociated with going to a larger profile cam.
I think that if you have a reason that you think you need to set your idle and tps,try it!! If it doesnt work for you, then you wasted 20 min of your precious time..If it does work then you saved some money and corrected your idle issue.
first off you guy are giving computers way too much credit there is not a computer in the world that zero's out input otherwise there would be no purpose for putting a input sensor in (tps).if it didnt matter where they where set then you should need one acording to what your saying set the tps voltage up does affect idle and it also give better response even on a 94/95 and even obd2
Dude, stop talking out your ass. Of course there's computers that zero out inputs. How about fancy scales, sometimes the input is off by a few lbs, you push a little button (which can also be done on every power up) that zeros the weight value. Think of a TPS as the flat part of the scale you put things on. A 5 lb bag of potatoes represents WOT. No matter where the scale is, after it's zero'd out it will still read 5 LBS OF WEIGHT!!! Just like the TPS, after it's zero'd out and you open the throttle blade, it will know how much you opened it because it still moved enough to increase the voltage by that much.
You said there'd be no purpose if it zero'd the value out, that's BS! It still needs to know how far the throttle blade is open at any given time. :bs:
Ecu sets start voltage as base, and scales from there. Gains from "adjusting" is about as much as gains from eating at subway instead of mcdonalds for one given day.
BTW to make it easier to visualize for those whose lips still move when they read, the computer doesn't "zero out" the sensor, it takes whatever voltage the sensor returns when the ignition is turned on and uses that voltage as a baseline for its future breakpoints for as long as the engine is running. Doesn't matter if it sees 0.5v or 1.0v at startup, its trigger points are added to that voltage.
if been work on cars at dealership for 10 years i know for a fact pcm dont zero out input just adjust for them adjust fuel idle etc not zero the inputs jack---
:lol: Reason 1001 why most of us don't take our cars to stealerships for work.
Next I fully expect you to whip out your "ASE Certified" card, the one unfortunately used by dumbasses the world over to support their ignorant positions.
just because you work for a dealership doesn't mean you know how the EEC works.
Thats why we can't take our cars to a dealership to get them re-tuned for aftermarket parts, blowers etc.
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