# TPS adjustment: Why is this good or bad?



## Sethticlees (May 30, 2002)

I don't understand the TPS mod. Why is it a good idea to adjust the TPS?

From what I can tell TPS just gives you a faster idle. Are there any other benefits of adjusting the TPS?

On a side note:
While I was in the FSM I noticed the SE-R TPS has a higher Ohm rating @ 1-10 open throttle. The GA16 is @ .5-4 Ohm open throttle.
What up with that???


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## niky (Jul 20, 2002)

(off the top of my pointy blockhead)... probably to reflect the difference in throttle sizes... probably to relate to how much air is actually flowing?


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## James (Apr 29, 2002)

It's only good if it's not registering the right values. If the TPS is not adjusted correctly your car may either not think the car ever reaches WOT or it may think that at idle you are giving it gas... either way it reduces power.

I think both the SER and 1.6 have a range of .5-4 KILO ohms... I'm not sure on the SER but my FSM only gives for those values.


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## Sethticlees (May 30, 2002)

James- Both my 93 and 97 FSM put the GA16 @ 0.5- 4 Ohm WOT and SR20 @ 1- 10 Ohm. 
Voltage for both engines in 93 was 0.45v - 0.55v. Voltage for 97 TPS is 0.35v - 0.65v.

I'm just curious about what this will do? Not that I'm gunna swap or anything I’m just curious. 

What about the people who have swapped TB's?


niky- that’s an interesting theory. Can you tell me more?


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## James (Apr 29, 2002)

well it doesn't matter with what size as much as how much it is open, that is what the reading will tell the ecu and I believe the TPS is a component of how the ecu selects maps... I read on teh sr20 forums that if the voltage shows over .45 for any reason the ecu will go haywire inot some self diagnostic mode. and if it does not read .45 the ecu will never know that the car is at full throttle...

well I haven't seen any other fsm but I always thought that the tps was the same measurement in all ecus, guess you're right though if you have a FSM in front of you.


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## Centurion (Sep 5, 2002)

I thought that this so-called mod "tricks" the ECU into thinking that the pedal is depressed more than it normally would be and hence richens the fuel mixture. (?)


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## Sethticlees (May 30, 2002)

> well it doesn't matter with what size as much as how much it is open, that is what the reading will tell the ecu and I believe the TPS is a component of how the ecu selects maps... I read on teh sr20 forums that if the voltage shows over .45 for any reason the ecu will go haywire inot some self diagnostic mode. and if it does not read .45 the ecu will never know that the car is at full throttle...


I totally agree with that first statement but those voltage numbers can't be right can they?

The 93' FSM says at idle TPS should be set @ between .45v - .55v.

The 97' FSM says at idle TPS should be set @ between .35v - .65v. 

When you open the throttle the voltage increases to something like 6.0v. 


Really, my own personal concern, for my 93' is should the TPS be set closer to .45v or .55v during idle? Why?


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## James (Apr 29, 2002)

so the ecu knows the throttle is closed... here's my personal experience... a while ago my tps was off like reading .7kohms at idle, but I didn't know that at the time but every night on the way home like the last stretch of road, the idle speed would be at like freakin 2500 rpm even when I put it in gear... in neutral it would be like 2000k! 

So i tested the tps and replaced it, never happend again.


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## Sethticlees (May 30, 2002)

So from your experience James, could it be said that with .7 Ohm (the norm being .5 Ohm) your engine reacted by producing a faster idle? You said about as high as 2500 RMP or 2000 in neutral.

This is very interesting. So 2/10th's of an Ohm difference and you got ~1150 RPM difference.

So imagine the SE-R TPS on a GA16 engine. Right off the bat you know it rates 1-10 Ohm. So that’s a .5 Ohm increase @ idle alone. 
On the extreme end you'll be getting about 10 Ohm's at WOT, the norm is only 4 Ohm.

I'm beginning to think I know why fucking with the TPS makes people believe there getting more power.


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## niky (Jul 20, 2002)

more likely, they're just getting black plugs from an over-rich mixture... who knows? has this trick been dyno'ed and documented?


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## James (Apr 29, 2002)

Sethticlees said:


> *So from your experience James, could it be said that with .7 Ohm (the norm being .5 Ohm) your engine reacted by producing a faster idle? You said about as high as 2500 RMP or 2000 in neutral.
> 
> This is very interesting. So 2/10th's of an Ohm difference and you got ~1150 RPM difference.
> 
> ...


I'm not sure exactly where it was at... I was just using that figure as an example but it was screwed up trying to come to a stop when you're engine refuses to come down! It's like the second I took my foot off the brake I'd burst into speed!!!


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## Sethticlees (May 30, 2002)

James said:


> *I'm not sure exactly where it was at... I was just using that figure as an example *


Yeah, but the basic principals are the same. Thanks for the info man.

I'm just gunna stick with the stock settings for now until I figure this all out.


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## James (Apr 29, 2002)

I know the thread is old but this picture is for the archives... well hopefully I never delete it from my page...










It shows how the tps is checked.


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## Sethticlees (May 30, 2002)

I'll second that with the SR TPS


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## etepsnewo (Jul 5, 2008)

I know this is a really old post but I had an experience lately that might be helpful to others concerning this:

I suspected my car's slow acceleration/throttle response could be do to a bad TPS so replaced it. Turns out it has likely been a combination of problems since the car has well over 200K on it but that's another story. On to the relevant part. 

I had installed and set the new TPS based on the idle position voltage .45 to .55 and the car still had bad hesitation problems at start off. I disconnected the harness connector from the TPS and it ran great, actually TOO good. My Torque Phone ap showed the TPS reading at 100% with it unplugged. The engine idles at base idle setting of 650 to 700 in park or neutral but as soon as it is put in Drive or Reverse it goes to 1100 RPM. Plus when cold it idles at 2200 RPM until it warms up. Since the engine seams to like a TPS higher resistance setting to accelerate better I turned off the engine and plugged the TPS back in started the engine and readjusted it so at Idle it was turning about 2000 in Park. NOW ! Here is the cool part. To get the engine to idle normally but keep the TPS in this more advanced setting that I believe would make the car run better, I turned off the engine and unplugged the TPS harness. Restarted the car with the TPS unplugged ( it idled again at 650 base idle ) and I plugged the TPS back in. It revved back up to the 2000 RPM but then slowed back down to about 1100 RPM.  . That was not low enough so I turned the engine off and waited about 15 seconds before I turned the ignition back on, waited about 10 seconds and restarted the car. It revved up to about 1100 RPM and immediate reduced the idle to about 750. Took it for a test drive and wow, it accelerates and drives so much better now. I think they call that resetting the idle memory in the ECM. Fingers crossed it continues to run this well.


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