tps...??

[the_kage]

Went to look at houses yesterday and the check engine light came on.
Drove down to the friendly neighborhood AutoZone to scan my car for an engine code.
Two codes came up. Both were Throttle Position Switch/Sensor.
They wanted $144 for a new one.
So can I find one on ebay from a 1st gen or any other ride?
Lemme know...

[brandon]

You can't use a 1G, but you CAN use a 2G.

Unless you're swapping or have already swapped to a 60mm TB...

[STL95LS]

My local dealer here only charges $85 for a TPS sensor. $144 for AutoCrap unit is unheard of.

[JiP]

The 2g ones usually pop up on ebay for like $20

Are your sure its completely busted?? Having any driving/tranny problems? Cause a busted TPS will cause havoc, especially with your tranny changing gears. If your not having any driving issues, clear the code and see if it comes back right away.

What where the exact codes that came up??

[the_kage]

i dunno if this matters jip.. but im 5 speed.
umm.. i dont know the exact code.. but I will have it cleared and let you knwo if it comes back.

[JiP]

<div class='quotetop'>QUOTE(the_kage)</div><div class='quotemain'>i dunno if this matters jip.. but im 5 speed.
umm.. i dont know the exact code.. but I will have it cleared and let you knwo if it comes back.</div>

Well obviously your tranny wont have shift problems then =D. On the A/T a dead TPS will make your tranny computer go insane it doesnt know where to shift and gets stuck in gears etc..

Rob

[brandon]

I'm wondering if my TPS might be the cause of my problems... does the harness that plugs in to the TPS need to have that little metal wire around it? Does it conduct anything?

I broke the plastic on my harness and that metal piece that goes around the outer edge popped out... won't stay in with it broken.

No CEL for it though...

[JiP]

<div class='quotetop'>QUOTE(brandon)</div><div class='quotemain'>I'm wondering if my TPS might be the cause of my problems... does the harness that plugs in to the TPS need to have that little metal wire around it? Does it conduct anything?

I broke the plastic on my harness and that metal piece that goes around the outer edge popped out... won't stay in with it broken.

No CEL for it though...</div>

Nope, that wire is there to apply pressure to keep the harness connected. For some reason they didnt use a connector with those PUSH TO RELEASE things, they had to make life dificult for us. Without the metal part though your connector may fall off just check and make sure its snug if not zip tie it on or something to make sure it doesnt fall off.

[brandon]

Well that's good to know. I was thinking about getting another harness and just wiring it in to be sure, but I think I'll see how my new O2 sensor helps things once I get it.

[JiP]

<div class='quotetop'>QUOTE(brandon)</div><div class='quotemain'>Well that's good to know. I was thinking about getting another harness and just wiring it in to be sure, but I think I'll see how my new O2 sensor helps things once I get it.</div>

Why whats your prob? You just recently turbo'd right?

[brandon]

Problem is I'm getting idle surge... also feels like fuel cut sporadically while driving.

I'm venting the BOV back to the intake, but nothing changed. My other guess was a leak, but everything seems to be plugged up.

[JiP]

Well I assume you have a logger..cause you should =P ..you would be able to tell if your TPS wasnt working right by the logs.

[brandon]

Well that's the thing, what is the TPS supposed to be reading? I figured it'd be reading 0-100 per the throttle opening, no?

i.e. TPS = 10, Throttle is 10% open

[Livn2sk8]

Man I wish I was turbo!!!

[JiP]

Yes Brandon,

So at idle no foot on gas should be 0% or at max 5%. Some TPS's cant get down to 0% but more importantly WOT must read 100%. So have a friend sit in your car with his foot to the floor on the gas (car ON engine OFF and datalogger conected) and adjust the TPS until it reads 100%, but right on the very edge of just turning 100%. This way with no throttle the TPS will be at its lowest setting possible wich should be 0% but most are around 3-5%. The hard part is tightening the bolts on the TPS without budging the thing and changing the readings.

But other then that, the amount of throttle you give is what the TPS reads, the only way I can think to realy test a TPS is to be in an open parking lot and start from idle and watch ur logger as you slowly give gas until you hit WOT and your TPS graph should be a smooth rise from 0-100% with no dips or spikes or flat spots.

It very well may be a vacuum leak somewhere..

[Livn2sk8]

ok, i'm realizing something as i'm reading this, the TPS is that part that is screwed/bolted onto the front side of the TB right? and has a harness that gets plugged into....

only because...I took my TB off to clean it and when I did this, I took that piece off, if it is the TPS...I just screwed it back on, I was stupid and didn't think it mattered at what position I put it back on. If so, my car has been idling funny lately, example.....goes beyond my "set idle rpm" and then comes back up...only by 100-200 rpm...but, could this be the cause.

Sorry if this is a change of topic for everyone!!!

[JiP]

It could be the cause, but lets say you have the TPS reading 20% at idle, the ecu thinks the throttle plate is open 20% and is gona dump more fuel, its not gona care about controling idle because it thinks the throttle is open..etc.etc... so fix it =P

[brandon]

I actually made sure the TPS was in the right position by using my AFC. I remember after taking off the TPS and re-installing it at some point, my throttle reading was showing 5%+ with it closed shut.

After some adjusting (to around 1% while closed), it slowly corrected itself to 0%.

I just looked through a new log on my lunch and noticed at idle (600-800RPM, closed throttle), the TPS was reading 1 on the logger, where I know the AFC had to be showing 0%.

Close enough I suppose. I also found that I'm running pretty rich, so I'm gonna make some adjustments later.

Planning a trip to the track on Sunday. https://www.thegalantcenter.org/style_emoticons/default/smile.gif

[Livn2sk8]

Is there anyway of adjusting the TPS without having a logger? I don't have one, also, where can I get one? obviously, it is something of importance....and how much am I looking at? and i'm not wanting something cheap in quality, but nothing overly priced, ya know? Thanks in Advance!

[brandon]

You can adjust your TPS whenever you want, but you won't really know how accurate it is without a logger or AFC.

You can buy the software from www.pocketlogger.com and then you'll just need to get a compatible palm. It'll run you around $200 but it's money very well spent if you plan to modify your car.

Also hope you are OBD-II if you do get one.

[Russian7G]

He is GS, that means DOHC, that means 94, that means pre-OBD-II..

[rfpa1]

On this case you can use a voltmeter setup for OHMS. When closed is 0ohms and open I think is 50 or something like that. I can check my book tonight and reply tomorrow.

The TPS generates resistance as it opens and this goes to the ECU to report how much the engine needs to adjust or compesante so the car gets the right amount of gas.

Also on 94 and 95 the dealer can read the codes and or problems with any sensor. No other logger (that is not like 2000$ will do it (as far as I know besides the MUT II reader).

[brandon]

Yeah, forgot you were 94 GS... I don't know if the OBD-I pocketlogger software would work or not.

I believe there are expensive dataloggers you can buy that give you the same readings the pocketlogger can (rather than the ones that just read and clear CEL codes).

[Livn2sk8]

Thanks for the help guys!

[JiP]

Bradon, the AFC will zero out the TPS signal. So if your TPS reads 5% at startup or idling for too long the AFC will report it at 0%. So its kinda not the best way to do it. However if you want to use the AFC the correct way to do it would be to go to the Sensor Voltages menu and look at the voltage levels and set it up as if you were using a volt meter. But since you have a logger, just make sure WOT is 100% you can do it with the key ON engine OFF and just floor the throttle.

And no logger or safc just use a voltmeter I forget the exact voltages off the top of my head though..

[Livn2sk8]

what do I hook the voltmeter to? if i put it on the TPS, there wouldn't be any voltage, at least, I wouldn't think so, because i'd have to disconnect it, to use any connections?........forgive me if i'm confused...

[brandon]

<div class='quotetop'>QUOTE(JiP)</div><div class='quotemain'>Bradon, the AFC will zero out the TPS signal. Â*So if your TPS reads 5% at startup or idling for too long the AFC will report it at 0%. Â*So its kinda not the best way to do it. Â*However if you want to use the AFC the correct way to do it would be to go to the Sensor Voltages menu and look at the voltage levels and set it up as if you were using a volt meter. Â*But since you have a logger, just make sure WOT is 100% you can do it with the key ON engine OFF and just floor the throttle.

And no logger or safc just use a voltmeter I forget the exact voltages off the top of my head though..</div>

So the AFC will zero it out after idling no matter what position it's in? Interesting.

[JiP]

<div class='quotetop'>QUOTE(Livn2sk8)</div><div class='quotemain'>what do I hook the voltmeter to? if i put it on the TPS, there wouldn't be any voltage, at least, I wouldn't think so, because i'd have to disconnect it, to use any connections?........forgive me if i'm confused...</div>

You have to back probe the connector. If your meter has needle like probes your set but most dont, so easiest way is to take a pin and stick it in the back of the connector where the wire goes into the connector and atattch the meter probe to the pin, the negative probe to ground, anything intake manifold will do.

This topic has been covered before its up here somewhere.

[rfpa1]

here it goes:

1) you are NOT looking for volts, you are looking for Ohms.


2) Unplug the TPS cable

3) on the tps - make sure is closed.

from left to right (pin1 and pin 4 the ohms should be between 3.5 and 6.5K
now check pins 2 and 4 - start openning the trottle slowly, it should change slowly if it jumps from like 0 to 50 , as you open it then it has a problem.


Also note that the tps should be at 0 when closed and infinity at full open.

If you need to replace it check that the tps position in the (adjusting bolt in the back by the cable have an openning of .45mm


If you need the voltage check pins 2 and 4 and key on engine off it should be up to 1000 mv.


This is for the 94/95 galant 4g64

[JiP]

No offense but thats not really help to anyone without pin numbers. Saying the TPS should be 0 when closed and infinite when open means nothing, the Closed throttle switch thats built into the TPS wich is like pin 3 should be 0 and infinite when open.

And going by ohms wont work well since every tps will measure different the variable resistors inside will be way different from each other in readings. Thats why you go by voltage levels so you can set your individual tps to read the correct output voltage wich is what the ecu will read, not the resistance.

[Livn2sk8]

According to my chilton, to properly install the tps back on the TB, all you need to do, is slide it into place, and turn it clockwise all the way, and then screw it down, this way, the slots on the TPS will be all the way touching the screw.....(if you get me).....I did this, and now my idle is back up again, but now, sometimes it's fluctuating, or it sits at 1k rpm or 1200 rpm.......soo....any ideas fellas?

[JiP]

Thats because sometimes chiltons is a POS. Your TPS will end up being positioned so the mounting bolts are about in the center of the slots.

From manual cd...just says with no throttle pins 2 and 4 should measure .4v to 1v. Its really a big pain to do with a meter cause you cant get an exact level to get it perfect cause everyones TPS resistance is different and ecu internal parts tolerance are different..and bla.. the best way is just to use a logger so you can see what the ecu see's

[rfpa1]

BY the way, the resistance on a new TPS is supposed to be the same plus or minus a small percentage. This is according to the Mitsu Book not the Chilton. I have lots of books and CD info on the 94/95 Galant and some 95 to 98.

The problem is that the TPS sensor is only one of a few sensors that work in conjunction to allow the car to behave properly.

The TPS works with the following:

IAC, Water Temp Sensor ( The big sensor that is on the head by the water temp sender and turn on the FANS), also uses the EGR and the Speed Sensor. All of this info is forwarded to the ECU were is mixed with info from the Oxigen sensors and then comes up with the necessary adjustments.

So to check for the Idle that varies like our problem we have to really look at the system as a whole. Just looking at this or that does not cut it. I replaced the IAC and found the Water sensor bad.


If you really want to do some real adjustments on this system you will need to replace the ECU and do some more programming utilizing a higher end Diagnostic System.

If I could afford the MUT II tool to use on my car I would have bought it. I think it comes to around 2K for all the parts needed.

Iam currently working on finding something like this to use on my ride without spending lots of $$$$.

[brandon]

Used my logger Saturday and my TPS reads 0-1 when closed, 97 when fully open. Too lazy to adjust for 3%. https://www.thegalantcenter.org/style_emoticons/default/tongue.gif

[Livn2sk8]

Any benefits of OBD-I, compared to OBD-II?

Also, depending on which one is better, is it possible to convert from OBD-I, to OBD-II?

just curious, as I'm unable to find a logger for OBD-I, that has much, if any, use.

[brandon]

In order to switch to OBD-II, you'd need to swap your ECU.

Because you have the GS, the swap would be a little easier for you as you don't have to do all the coil pack transistor stuff.

Which makes me think, which TB does the GS have?

[JiP]

Ye you'd have to swap ecu's, but the only person I know that knows the GS electronics is this guy Nathan on 4g64 yahoo groups. IIRC GS has 2g style intake with a 60mm TB, but I could be wrong.

OBD1 doesnt have much support, obd2 loggers can be bought for $100-$250. It will answer all your questions in 2 seconds, if your TPS is off, your ECT isnt working right, etc etc.. If you do a lot of modding and screwing around its the best tool to have. Its probably not worth the cash for someone who is stock and has a problem every now and then.

the only thing I like better in OBD1 is the knock count. There was a post somewhere about the differences between the 2 a couple months back.

[brandon]

Kind of off-topic, but not really....

When probing the back of the connector how far should the probe go? I had a devil of a time probing the thing and decided I didn't want to ruin the connector.

Also, when adjusting the BISS, I thought backing it out was supposed to raise the idle?

[JiP]

Kind of off-topic, but not really....

When probing the back of the connector how far should the probe go? I had a devil of a time probing the thing and decided I didn't want to ruin the connector.

Also, when adjusting the BISS, I thought backing it out was supposed to raise the idle?

I use a sewing Pin or a saftey pin and stick it down in until it stops. If you want to check pull the connector off and check continuity between the pin on the inside of the conector and the sewing pin u stuck in the top to make sure its making contact then reconnect it and do what you gotta do..


And yes the BISS will raise the idle if you back it out. Either your BISS bypass hole that lets the extra air flow through is clogged. Or maybe your IAC is closing to compensate to keep it where the ecu wants it, but never heard of that one before just a guess.