i need help with my throttle positioning sensor. does anyone know where i can get any info on how to adjust it?

 

Search for "TPS" and the likes by TomP. IMO, he is the resident GENIOUS in this forum...

I believe he told me that .550vdc at idle and above 4vdc at WOT are the correct adjustments.

 

try this link here, it should give you what you want to know:


https://www.thirdgen.org/newdesign/tech/tpimod2.shtml

 

(laughs) I wouldn't go quite that far; I'm pretty idiotic in most things. I've just had a lot of experience with f-bodies, and without websites like thirdgen.org and members in forums like this, I wouldn't know half the things I do. And the search key is pretty damn helpful, too!

You'll need a digital voltmeter to adjust the TPS; you can find cheap ones that'll do the job for $10. In fact, I was in Radio Shack back around Christmas, and they had one for $10, too.

 

tom i just installed a new tps.. so am i hearing right and i should have my vlt scale on millivolts instead of regular dc volts? cause right now with it that way its coming in at .070 runs good but throws a code!?.. any help would be greatly aprreciated!

 

I just set mine up tonight, and I must say, it's the best it's idled since I can remember...



Idle with IAC disabled and ECU in diagnostic mode:

Minimum idle speed setting = 570.6 RPM

TPS at idle = 0.540vdc

TPS at WOT = 4.361vdc



Idle with the IAC enabled and ECU normal mode:

Low = 838.8 RPM

AVG. = 858.0 RPM

High = 883.8 RPM

 

Most meters millivolt scale maxes out at 300mv or 400mv. Unless your DMM range is higher, use the standard VDC mode.

 

hey thats coool ...but my meter is digital(a fluke meter)and when i adjust it it reads like .065 or i have it now .070 what gives is there another scale on those types of meters? wide open is 4.10 or something close to that.I think i will try the millivolts tonight if its not raining :

 

oops forgot to ask ...what do you mean iac disabled and in ecu diagnostic mode my car wont run with it unplugged at all starts give it gas but as soon as u let off it dies i tried to adjust the idle screw way out to give it more but it doesnt matter !

 

Are you adjusting for a V6? If so, where is the adjustment on the v6 models? I thought only the v8's were adjustable.

 

if your talking about the iac its on the left side of the tb a little star head screw to adjust the idle.

 

Nope, I meant the TPS that is right under the IAC on a V6.

 

from what i can tell it is yes it mounts on the side basically like a v8 i would say

 

Yes, but I am curious on how you adjust the actual sensor. Do you leave it on the nitch it plugs into screwed in and just twist it until you attain the proper voltage? Because I think it just twists back in place or does it stay adjusted? Need this info. Thanks.

 

The TPS is attached with 2 slotted tabs. Screws go into the TB, and you can loosen the screws and rotate the TPS.

What model Fluke do you have? I have the 179... Great meter!

I'll take a pic later and post it up here to hopefully clear things up...

 

Not sure on the model fluke its at work right now ,....but i got it fixed went down to my friends tranny shop and the sensor either it was 2 wrong ones or something i dont know but we had to bend the tang up to get it to come into spec and it worked perfectly!!!!! Adjusted it to .56 v at idle and has 4.78 v wot!!!!! I will post a pic this weekend to show you all what i am talking about ok. I am happy as helll the lights out to which makes sense thats why i could only get it to .070 cause it wasnt even beginning to read it till part throttle but it worked dont know if its the way it suppose to be for the tang but who cares it looks like thats the way they should be if there not what a simple design i should build them.lol sorry for long post! lol

 

1) Start the car, and warm up the engine. Shut the engine off.

2) Put a paperclip bent in the shape of a "U" into the DLC diagnostic port under the dash into the two right-hand most pins in the upper row.

3) Turn the key to RUN.

4) Wait 30 seconds, and then unplug the IAC motor. It will be in the closed position, thus not allowing idle air to pass around the throttle blade.

5) Start the engine and set the minimum idle speed to the proper spec. (If the idle air is too low, you may need to press the gas a bit to keep the engine running until you set the idle high enough to keep it running.) I set mine to the lowest I could without stalling, and for me that was around 570 RPM.

6) When minimum idle is set, turn off engine and plug IAC motor back in, and remove paperclip.

This is the procedure I used, and it appears to work. Your results may vary...

 

Here's the pic:

 

I apologize that I cannot seem to get my pic uploaded... I'll try again here...

 

coool can you take one to show what the tang looks like on the sensor if u can

 

Like this?

 

yes perfect! that part that is resting on your throttle body shaft is the part i bent up kinda like the other side of the tps is the only way i could get it in spec was out of adjustment the way it came new i will post a pic this weekend to show you but mine looks exactly like that except for the mod Is your a v-8 or 6?

 

ooops sorry i see your nick is gp so guessing a 3.1 am i right?

 

Nope. 2.8L. I am "BackInBlack" on clubgp.com, and it was already taken by the time I got here, so I added the "GP" part...

 

Ok those pics were for the V8 model. Im curious on how to adjust a TPS on a V6 model because currently im idling at 1300 rpms and when I change gears the car gallops quite a bit (Timing problem most likely), however I can't fix the timing until I have the rpm's down. I've already replaced both my IAC and TPS. Is the v6 TPS even adjustable?

 

we'll my car is an 89 firebird and it was so i would say yes they are ..but i guess depends what u have also? v-6's tps looks just like that v-8 one in the pic .I will take a pic this weekend of my mod ok

 

V8? What V8?

My photos are from my 2.8L V6.

The TPS is definately adjustable. I've done it many times...

Do a search on how to adjust the TPS, or you can use my procedure for the 2.8L that I posted above...

 

for some reason we got v-8 on the brain ..sorry man .lol

 

Strange, my TPS sensor looks totally different. I'll post a pic as soon as I can, I didn't mean it as a harsh remark but mine looks nothing like that (will post pics as soon as its back from the shop, its getting painted). I have a 3.1 91 camaro if that makes a difference.

 

yes i am not sure if those are adjustable or not hopefullly someone with more knowledge will jump in here

 

Anyone know if the 3.1 V6 camaro's TPS sensor is adjustable? If so how?

 

3.1's TPS's are auto-adjusting. The computer takes note of the minimum value of the TPS when you start the car, and bases the rest of it's values on that initial reading.

I think the 3.1 TPS's also have a different plug... is that right?

I have a fluke 73... damn that thing is nice! I love the analog bargraph on the bottom of the display.

 

Yup, its a round plug.

 

Tom: Those Fluke 70 series are great meters! Darn near bulletproof. I've already had to replace the LCD on mine and it's only 2 years old!

Pasky: What's the meaning of your screen name?

The 3100 in my wife's Grand Prix has a non-adjustable TPS. There is a rediculous procedure for setting it and the idle speed via the computer...

 

this post is a little old, but can someone help me and circle the IAC valve on one of those pictures up there? ive successfully confused myself beyond belief

thanks!

 

Anyone ever tired other settings??? tried to find a sweet spot better than factory???

Someone has to of, right???

Matt

 

IAC is the sensor on top of the throttle body, on the passenger side of the throttle body- it has a 4-wire connector.

I never played with any settings; stock is probably best because it's what the computer expects!

 

That sounds like something I should check. I've learned a good deal about cars, especially my car since I got it. I couldn't do it without my GM service manual and thirdgen.org though. You have the manual don't you TomP? In the emissions section it has all the emissions system diagnostic charts for checking the systems if no code is thrown. I should go through those.

 

thanks a lot, i think i found it. haha. once we get back from vacation, im going to clean it up, reset it, and adjust that TPS.

my father grew up fixing his own cars and stuff, and is more of an oldschool hot rodder, the kind where computer's scare them, and carburators were the big thing lol. is adjusting the TPS with a VOM going to be that difficult for us? from reading the searches, it sounds easy, since all were doing is connecting the meter to the sensor via wires, then rotating the TPS itself until it reads the right voltage?

 

Yep, the GM Shop Manual (or GM Service manual, however you want to call it ) was the first thing I bought for my car- back in 1994!

Yeah, adjusting the TPS is a no-brainer; be careful on the metal screws for the TPS, though. Don't muscle 'em; they like to snap easily. Remember too that you're squeezing a plastic "tab" between the screw and the aluminum throttle body- so don't overtighten the screws!

 

If the TPS is not adjustable from the factory you can make it adjustable. But unless there is a real reason to, this may cause more harm than it's worth.

 

If I check the TPS at WOT and it gives the right reading, does that imply that the TPS is set correctly everywhere?

 

That's exactly what I did to my 89 RS about a year and half ago. Worked good for me too.

-Dan

 

So the engine gets started while the ALDL connector has the jumper (paper clip) in it?? I thought that could damage the computer...

Oh and don't adjust the TPS at WOT. Adjust it only at idle. The computer will know when to engage PE mode after a certain percentage "above" idle speed- I was told anywhere over 4 volts is enough, even though the GM book says 4.50 at WOT. Most I could ever get mine set (while obeying idle voltage) was 4.28 volts.

 

So basically in #5, set the idle to the lowest it will still run at, and in #6 adjust the TPS, then reset the idle and put everything back together?

 

Minimum idle isn't really dependant on the TPS... do the TPS after you're done with the minimum idle (I guess if you want to make it a step, make it step #7.)

 

Well, lets say you adjust the tps from .50 volts to .56 like I did today, the idle suddengly jumped to 1200 rpms even after I disconnected my hand held scanner thing. So, I shut her off, unplugged the batt for 5 mins. After plugging it back in and then restarted her, it idled fine again. I figure it's a good idea to reset the computer anyway so it can build proper values based on the new set up of the TPS.

-Dan

 

Hm, I don't use the paper clip trick. I have a scanner I turn on after the engine is running that connects to the ALDL port, and I just put it on its 'monitor' mode and switch the sensor view to tps and watch the voltage, and adjust it then.

The paper clip idea makes me kinda paranoid anyway. *shrug*

-Dan

 

question on checking the TPS with a VOM... with the volt ohm meter, how did you connect it to read the voltage? i read somewhere you make jumper wires? i cant find out what they mean by that, or where to connect them. my understanding from reading the tech article was just touch the pins of the VOM to the unplugged TPS on the throttle body, and that would read the voltage when the ignition is on? or am i supposed to somehow touch the wires in back of the plug itslef to get the voltage?

 

On other vehicles that I havn't had a handheld scanner to use to read the values, I have been able to backprobe into the plug itself. Been able to do that with certain types of o2 sensors (the ones with two or more wires), and the tps.

-Dan