This worked for me. The throttle position sensor is to be set at .54 volts give or take .075, set it at about .59 ,it's still within spec but advances it a little. Also make sure that you have over 4 volts at WOT.
To measure your TPS put three jumper wires from connecter to sensor [and don't ground them by mistake] then put a voltmeter on the top two, I believe A & B. turn key on, don't start engine.adjust by loosening screws and moving.

 

Hey I don't want to hurt your feelings but your wrong, you can't adjust the TPS sensor on a V6, you may think you did because you change the value of votage but to the computer it's STILL LESS THEN 1 volt so it does what is called auto zeroing, meaning anything less then 1 volt from the TPS means closed trottle, sorry, no adjustment.

 

then why is it that adjusting to spec has to be .54 volts give or take only .075, If it zero's out why not just adjust it to .50 give or take .50. This did give me a noticible throttle response improvement.

 

Oh and if its adjusted higher it hits 1 volt sooner right...better response!

 

Don't get mad, I'm just telling you the facts out of a 1992 Camaro GM Factory Repair Shop Manual.

Because the spec is just TO TEST THE TPS to make sure it's not shorting out and THAT IT DOES NOT have a dead spot in it, thats the worst thing that happens to the TPS, they get dead spots in them, but not bad enough to set a code, but enough to mess up drive ability.

Remember, the ECM does not use the TPS to ratio out fuel, only to know when driveing conditions and to know when the trottle plate is open and where it is and to know when it is shut to opperate the IAC.

If you want I can run through the whole fuel ratio system and throttle response protocals but it's a lot of typing.

The best thing to have fixed or replace for better trottle response is the MAP sensor, becasue this is what tells the computer how much load the engine has on it based on vacum.

 

Better Throttle Response = Complete ignition, not adjusting the TPS. I Am sorry but rotating it forward it only going to get it above 1volt a milli second before you would have done it with your foot.
IF you want better respose, on a V6 since you cant readily adjudt the fuel pressure or timing, you just have to get an ignition box and a better coil and everything else to get the extra spark to the cylinders.
ON Most cars you can bump the Fuel pressure like 1 or 2 psi, but not enough to run rich, bum the timning a degree or two in advance, roll the TPS back a tad and rune 93 octane gas, with a good Ignition set up.

Sorry with the V6's you are basically stuck where you are. There is just not that many adjustments

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89 Trans Am Turbo 3.8L All stock 43,000 miles #1053 of 1555

Past Thirdgen:
86 Trans Am w/ built 355TPI with SLP goodies and too much other stuff to List. One sweet *** car, wish I would have had a good enough Job to pay insurance on three cars so I could keep it, but for a 89 Turbo Trans Am w/ Low miles, I think I made the right choice!

 

In 92 there is a big difference as far as sensors and engine operation. For example you have a MAP sensor. my 88 has a MAF senor.fuel mixture is not controlled by just one sensor. It's controlled by all of them together.also the TPS controls more than the IAC..unplug your tps and see how she runs at 20 mph, when the IAC is shut.I'm not mad, but I had a pain in the *** throttle response problem and believe or not this helped noticibly..don't knock it till you try it.

 

Actually Ryan, you're wrong... (sorry)

The 2.8's TPS is fully adjustable, and can be done just as Colincamaro said. You're quoting a '92 book which does NOT apply to the '85-'89 2.8's!

The 3.1's have the nonadjustable TPS.

2.8's can be adjusted just like the "big guys", the V8 TPI systems. In fact, TomK wrote an article about it for Hot Rod magazine- and then he typed it up for us here, in thirdgen.org. Hot Rod advertised the article as a "free TPI mod", and went on to say that everyone forgets about the TPS adjustment, and you can gain back some power and throttle response by a correct adjustment.

The thirdgen.org link to TomK's article is here: https://www.thirdgen.org/newdesign/tech/tpimod2.shtml

There are two torx screws that you loosen, and then spin the TPS to achieve the correct spec. In fact, Glenn told me that you don't need the full 4.50 volts (mentioned in the GM service manual) for the computer to determine WOT. He said anything above 4.0 volts tells the ECM to enter PE (power enrichment) mode for WOT. TomK's article also mentions that, but in less detail. Good thing too; I could only get my TPS to read a max of 4.29 volts when the throttle blade was wide open- no matter how I adjusted the TPS for idle. I was worried my ECM was never changing for WOT operation.

The adjustment is exactly the same for V8 TPI's and 2.8's MPFI's, with the exception of a slightly different idle voltage spec. I believe we're 0.55 +/- 0.05 volts; but don't quote me on that, I'll look it up tonight- in my '86 GM manual.

I also noticed an extra kick in the butt after doing this adjustment two years ago. It's probably time I did it again!

And, odd; I could've sworn I posted this yesterday; thirdgen.org must've crashed for a few seconds, eh?

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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

[This message has been edited by TomP (edited July 20, 2001).]

 

Well Tom in his orignal post he never did say what year he had and so for us 3.1 V6 (1990 - 1992) he is wrong, but I stand corrected on as far as the 2.8L becasue I never said what engine I was talking about BUT I DID SAY WHAT YEAR so away, chat later.

 

Dose the TPS ajustment just MPFI or for the 2bbl carbs to?

Robert

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Chevy 2.8L, k&n filter lid, Headers Soon!!!
http://www.geocities.com/fiream/RobsCarArtPa.html?994187591828

 

The 2bbl's have one; I'm not sure if it's adjustable or not. I also think you need a special tool. You can find it easy enough... if memory serves me, it's on the driver's side of the carb. The throttle linkage (on the passenger side of the carb) connects to a metal lever that extends over to the driver's side of the carb, at the front of the carb. Under the edge of the metal lever is a piston-looking thing; that's the TPS sensor.

[edit] I'm also not sure if you can measure it's reading the same way you can with the MPFI system... you might have to use different pins than top & bottom. Actually that 2bbl TPS might be a square connector; can't remember. . .

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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

[This message has been edited by TomP (edited July 20, 2001).]