TPS experiment
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Driver
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TPS experiment
If anyone has experimented with the tps voltage feel free to post your opinions.....
**All voltages were measured by a Fluke 77III multimeter**
I originally had my tps set to .45 and throttle response was fine but bogged a little and made taking off with a 8lbs flywheel and stage 3 clutch tricky ..but manageable ...idle was set a 900 and all ran well.
After 2 weeks the bogging was getting more noticeable so after checking the tps voltage today (2.5 weeks from initial setting) it was at .38.... WTF??!!
So after checking my friends honda (.49) and reading a few articles I decided to try it out at .45 and as close to .50 as I could get it without going over...
Every time I did search, I more often than not found .45 as a reference, to include one post written by myself quoting information I had read on the net.
And of all the articles I had read only one suggested that it be as close to .50 as possible and this particular article cited the helms as a refference..So I figured what the hell..
Well there were two significant differences in the two setting from what I noticed at the .449 setting the idle (900 rpm) was slightly smoother but the minute bog was still present at when I pressed the go pedal........Now the .497 setting had a slightly rough idle (still 900) but the bog was gone making the action of accelerating from a stop significantly easier.
Being that I have a pretty annoying stop and go drive to wotk every day I chose the .497 setting for the sake of making it less of a headache...but I still have to take more time driving it to make a real good evaluation (I only drove for about 30 minutes with each setting under the same conditions)
Here are some questions for you brains out there....
1) What is the setting that "Helms" recommends?
2) What exactly is the tps signal used as by the ecu?
3) Does the TPS signal directly affect the ignition timing?
4) If so, how?
5) If not , then what could possibly cause the slightly rougher idle?
6) How, if at all does the tps affect fuel flow?
And please feel free to add any observations you may have and help try to find an absolute answer (if possible) to what the TPS setting should be.
Well I'm going to sleep......But I will continue with my wandering bable in the morning :blah:
**All voltages were measured by a Fluke 77III multimeter**
I originally had my tps set to .45 and throttle response was fine but bogged a little and made taking off with a 8lbs flywheel and stage 3 clutch tricky ..but manageable ...idle was set a 900 and all ran well.
After 2 weeks the bogging was getting more noticeable so after checking the tps voltage today (2.5 weeks from initial setting) it was at .38.... WTF??!!
So after checking my friends honda (.49) and reading a few articles I decided to try it out at .45 and as close to .50 as I could get it without going over...
Every time I did search, I more often than not found .45 as a reference, to include one post written by myself quoting information I had read on the net.
And of all the articles I had read only one suggested that it be as close to .50 as possible and this particular article cited the helms as a refference..So I figured what the hell..
Well there were two significant differences in the two setting from what I noticed at the .449 setting the idle (900 rpm) was slightly smoother but the minute bog was still present at when I pressed the go pedal........Now the .497 setting had a slightly rough idle (still 900) but the bog was gone making the action of accelerating from a stop significantly easier.
Being that I have a pretty annoying stop and go drive to wotk every day I chose the .497 setting for the sake of making it less of a headache...but I still have to take more time driving it to make a real good evaluation (I only drove for about 30 minutes with each setting under the same conditions)
Here are some questions for you brains out there....
1) What is the setting that "Helms" recommends?
2) What exactly is the tps signal used as by the ecu?
3) Does the TPS signal directly affect the ignition timing?
4) If so, how?
5) If not , then what could possibly cause the slightly rougher idle?
6) How, if at all does the tps affect fuel flow?
And please feel free to add any observations you may have and help try to find an absolute answer (if possible) to what the TPS setting should be.
Well I'm going to sleep......But I will continue with my wandering bable in the morning :blah:
So OG it hurts.
Joined: Mar 1999
Posts: 6,592
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From: VA
i think most of what you are noticing is all in your head.
i ran my aftermarket ericks tb at .45xxx voltage idle was the same.
i had bogging during acceleration cause of a sticking tb.
you also want there to be 10-12 mm in slack on the tb cable.
make sure you tb cable isn't on too tight.
mine bogging issues where because of the tb, and once they were fixed. i had GREAT throttle response.
the voltage reading as far as i know tell the ecu how muc the throttlbody is open.
that and the map sensor tell the ecu how much air is coming in at what throttle position.
i ran my aftermarket ericks tb at .45xxx voltage idle was the same.
i had bogging during acceleration cause of a sticking tb.
you also want there to be 10-12 mm in slack on the tb cable.
make sure you tb cable isn't on too tight.
mine bogging issues where because of the tb, and once they were fixed. i had GREAT throttle response.
the voltage reading as far as i know tell the ecu how muc the throttlbody is open.
that and the map sensor tell the ecu how much air is coming in at what throttle position.
Thread Starter
Driver
Joined: Oct 2003
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Originally Posted by Bumnah
i think most of what you are noticing is all in your head.
i ran my aftermarket ericks tb at .45xxx voltage idle was the same.
i had bogging during acceleration cause of a sticking tb.
you also want there to be 10-12 mm in slack on the tb cable.
make sure you tb cable isn't on too tight.
mine bogging issues where because of the tb, and once they were fixed. i had GREAT throttle response.
the voltage reading as far as i know tell the ecu how muc the throttlebody is open.
that and the map sensor tell the ecu how much air is coming in at what throttle position.
i ran my aftermarket ericks tb at .45xxx voltage idle was the same.
i had bogging during acceleration cause of a sticking tb.
you also want there to be 10-12 mm in slack on the tb cable.
make sure you tb cable isn't on too tight.
mine bogging issues where because of the tb, and once they were fixed. i had GREAT throttle response.
the voltage reading as far as i know tell the ecu how muc the throttlebody is open.
that and the map sensor tell the ecu how much air is coming in at what throttle position.
Well as far as it being in my head... I thought the same thing so I let my wife drive it his morning and while she didn't notice any difference in idle she did notice that taking off was easier and it didn't feel like the car was gonna die.
And the bogging also used to occur while just steadily pressing on the accelerator at a stand still... So adjusting JUST the tps did make a difference...
I think my throttle cable has somewhat of the same slack but thanks for mentioning it... I'll check it out during lunch.
And I don't doubt that you had the same problem at the same voltage that I had it at but I'm inclined to believe that our problems had different causes since mine was remedied by adjusting the tps but like I said, I'll make sure to check it out.
Also the reason I asked the 6th question about how it affects fuel flow was that it felt like the engine was choking on fuel at takeoffs.
**STill looking for more answers to my Qs and input on everyones personal tps settings would be great**
Senior Member
Joined: Apr 2003
Posts: 176
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From: Indiana
First off, let me say that this thread is bitchen. Second off, I just tested my tps sensor yesterday, and my stock setting was .47. So I adjusted it to the "stock" setting. Which is .45, i did notice a little difference in the responce, I then adjusted it to as high as I could take it, which was .48. It idled a little differently, so I put it back to .47 which to me seemed to be a good median. As far as adjusting wot, does that even really matter, cause mine was at like 3.9 or something of that nature.
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Joined: Oct 2003
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Originally Posted by imlachg1
First off, let me say that this thread is bitchen. Second off, I just tested my tps sensor yesterday, and my stock setting was .47. So I adjusted it to the "stock" setting. Which is .45, i did notice a little difference in the responce, I then adjusted it to as high as I could take it, which was .48. It idled a little differently, so I put it back to .47 which to me seemed to be a good median. As far as adjusting wot, does that even really matter, cause mine was at like 3.9 or something of that nature.
Hmm Thanks for posting....and not to get you concerned....But 3.9 sounds low for wot but I've also read that the closed is all that matters....
I'm gonna try and find some all the information I can dig up on this....and post it..
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Joined: Oct 2003
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This is what I got from:
http://www.hondaswap.com/~pills/obd1guide.html
........
After performing a swap, many times the throttle position sensor on the engine is broken, forcing you to use one from your old d15 or d16 (or whichever you pulled). The Honda TPS has three wires coming from it: green/white , a red/blue , yellow/white. Your primary focus will be on the red/blue wire, as this is the one that sends a voltage to the ECU telling it how open or closed your throttle is. The ECU expects .5 volts to be closed throttle and 4.5 volts to be Wide Open Throttle (WOT). The red/blue wire goes to pin D11 at the ECU. Rotating the TPS will change the voltage, when you take it off, you'll notice that the holes are slotted so it can move. If you are fortunate enough to have Hondata Datalogging or an Apexi V-AFC you can use their inbuilt functions to read the TPS voltage. If you do not have such a device, you can use a Voltmeter or similar device. Ground one lead on the chassis somewhere and use touch the (+) lead to the pin on the TPS (should be the center pin) and measure the voltage. Rotate it until it reads .5 volts, then tighten it down. Have a friend press the gas pedal to the floor and also check that WOT reads 4.5 volts.
For those interested with the other two leads, and I know there has to be someone out there. The green/white wire ties into a braided wire with the Intake Air Temp Sensor and the Heated Oxygen Sensor and they all run to Pin D22 on the ECU which is a sensor ground that reads less than 1 volt while the car is started. The yellow/white wire goes to pin D20 on the ECU which is a reference voltage, where it gives about 5v with the Key on and engine off.
And from http://www.integra.orcon.net.nz/tps
.......
After doing this I noticed my idle wasn't quite right. The Honda manual I have says 0.45V but when I measure my stock TPS which was still set from the factory it was 0.32V so that is what I have mine set to. Once I had it set to 0.32 the idle was fine.
If you know someone with the same car you could measure their closed throttle voltage to see what their car has but try setting to 0.45V first. I suggest you measure your stock TPS setting before moving it so you can at least revert back to the original setting. There may be other Hondas which have settings other than 0.45 volts,
And from the str web site http://www.strpower.com/Inst/TB/strtb.html
............
On the factory TPS sensor, there are 3 wires. The center wire is “regulated voltage”. At CLOSED
throttle check the voltage reading of the center wire. The reading should be between 0.36 - 0.44 volts. Rotate the sensor clockwise or counter-clockwise until the reading falls within that range. Tighten the two screws. At WOT, the reading should be between 4.50 - 4.85 volts. Make adjustments as necessary
From a guy on HT at http://www.honda-tech.com/zerothread?id=844535
.....................
When the TB is closed it should be as close to .5 Volts as possible (Helms). Now on the STR site they are saying it should be between .38 and .44 volts. This is where I'm on the fence. I don't know who's to go with......
**this one above is the one that cited the helms as beiong as close to .5 as possible...this is the one that sparked my attention**
And from hondata themselves...http://www.hondata.com/techidle.html
The TPS tells the ECU what position the throttle is in. The TPS should read 0.45V when the throttle is released. It is critical that the TPS is adjusted correctly so that the ECU knows when the throttle is released, which tells the ECU that the engine is either idling, or the throttle is closed under load and the injectors should be switch off the save fuel (fuel over-run cutoff). Swapping ECUs that have different internal power supply characteristics can change the TPS voltage a small amount - in some cases enough to put it above 0,5V.
If the TPS is set negative (below 0.45V at idle) when you open the throttle slightly the ECU will think the throttle is not open, apply the fuel over-run routines and cut fuel at 1400 or 1800 rpm. This will often cause the revs to cycle between about 800 and 1800 rpm. Also the car will be jerky when driving around at low speed.
If the TPS is set positive (over 0.45V) then the fuel over-run routines won't work, and also the ECU will not run the correct idle routines to keep the idle steady. It's better to have the TPS adjusted slightly negative, but setting it to 0% if fairly easy with datalogging. Otherwise aim for 0.45V.
************************************************** *******
Ok now the hondata seems to clear up alot of questions on why the idle is rough due to not running the fuel over-run routines to keep the idle steady..
But if this were the case then Why would honda set a stock tps at .49??
Are the tps voltages that control the fuel over-run routines ecu specific?
hmmmmm :thinking:
http://www.hondaswap.com/~pills/obd1guide.html
........
After performing a swap, many times the throttle position sensor on the engine is broken, forcing you to use one from your old d15 or d16 (or whichever you pulled). The Honda TPS has three wires coming from it: green/white , a red/blue , yellow/white. Your primary focus will be on the red/blue wire, as this is the one that sends a voltage to the ECU telling it how open or closed your throttle is. The ECU expects .5 volts to be closed throttle and 4.5 volts to be Wide Open Throttle (WOT). The red/blue wire goes to pin D11 at the ECU. Rotating the TPS will change the voltage, when you take it off, you'll notice that the holes are slotted so it can move. If you are fortunate enough to have Hondata Datalogging or an Apexi V-AFC you can use their inbuilt functions to read the TPS voltage. If you do not have such a device, you can use a Voltmeter or similar device. Ground one lead on the chassis somewhere and use touch the (+) lead to the pin on the TPS (should be the center pin) and measure the voltage. Rotate it until it reads .5 volts, then tighten it down. Have a friend press the gas pedal to the floor and also check that WOT reads 4.5 volts.
For those interested with the other two leads, and I know there has to be someone out there. The green/white wire ties into a braided wire with the Intake Air Temp Sensor and the Heated Oxygen Sensor and they all run to Pin D22 on the ECU which is a sensor ground that reads less than 1 volt while the car is started. The yellow/white wire goes to pin D20 on the ECU which is a reference voltage, where it gives about 5v with the Key on and engine off.
And from http://www.integra.orcon.net.nz/tps
.......
After doing this I noticed my idle wasn't quite right. The Honda manual I have says 0.45V but when I measure my stock TPS which was still set from the factory it was 0.32V so that is what I have mine set to. Once I had it set to 0.32 the idle was fine.
If you know someone with the same car you could measure their closed throttle voltage to see what their car has but try setting to 0.45V first. I suggest you measure your stock TPS setting before moving it so you can at least revert back to the original setting. There may be other Hondas which have settings other than 0.45 volts,
And from the str web site http://www.strpower.com/Inst/TB/strtb.html
............
On the factory TPS sensor, there are 3 wires. The center wire is “regulated voltage”. At CLOSED
throttle check the voltage reading of the center wire. The reading should be between 0.36 - 0.44 volts. Rotate the sensor clockwise or counter-clockwise until the reading falls within that range. Tighten the two screws. At WOT, the reading should be between 4.50 - 4.85 volts. Make adjustments as necessary
From a guy on HT at http://www.honda-tech.com/zerothread?id=844535
.....................
When the TB is closed it should be as close to .5 Volts as possible (Helms). Now on the STR site they are saying it should be between .38 and .44 volts. This is where I'm on the fence. I don't know who's to go with......
**this one above is the one that cited the helms as beiong as close to .5 as possible...this is the one that sparked my attention**
And from hondata themselves...http://www.hondata.com/techidle.html
The TPS tells the ECU what position the throttle is in. The TPS should read 0.45V when the throttle is released. It is critical that the TPS is adjusted correctly so that the ECU knows when the throttle is released, which tells the ECU that the engine is either idling, or the throttle is closed under load and the injectors should be switch off the save fuel (fuel over-run cutoff). Swapping ECUs that have different internal power supply characteristics can change the TPS voltage a small amount - in some cases enough to put it above 0,5V.
If the TPS is set negative (below 0.45V at idle) when you open the throttle slightly the ECU will think the throttle is not open, apply the fuel over-run routines and cut fuel at 1400 or 1800 rpm. This will often cause the revs to cycle between about 800 and 1800 rpm. Also the car will be jerky when driving around at low speed.
If the TPS is set positive (over 0.45V) then the fuel over-run routines won't work, and also the ECU will not run the correct idle routines to keep the idle steady. It's better to have the TPS adjusted slightly negative, but setting it to 0% if fairly easy with datalogging. Otherwise aim for 0.45V.
************************************************** *******
Ok now the hondata seems to clear up alot of questions on why the idle is rough due to not running the fuel over-run routines to keep the idle steady..
But if this were the case then Why would honda set a stock tps at .49??
Are the tps voltages that control the fuel over-run routines ecu specific?
hmmmmm :thinking:
Senior Member
Joined: Apr 2003
Posts: 176
Likes: 0
From: Indiana
This is probally the best info I hav read
If the TPS is set negative (below 0.45V at idle) when you open the throttle slightly the ECU will think the throttle is not open, apply the fuel over-run routines and cut fuel at 1400 or 1800 rpm. This will often cause the revs to cycle between about 800 and 1800 rpm. Also the car will be jerky when driving around at low speed.
If the TPS is set positive (over 0.45V) then the fuel over-run routines won't work, and also the ECU will not run the correct idle routines to keep the idle steady. It's better to have the TPS adjusted slightly negative, but setting it to 0% if fairly easy with datalogging. Otherwise aim for 0.45V.
If the TPS is set negative (below 0.45V at idle) when you open the throttle slightly the ECU will think the throttle is not open, apply the fuel over-run routines and cut fuel at 1400 or 1800 rpm. This will often cause the revs to cycle between about 800 and 1800 rpm. Also the car will be jerky when driving around at low speed.
If the TPS is set positive (over 0.45V) then the fuel over-run routines won't work, and also the ECU will not run the correct idle routines to keep the idle steady. It's better to have the TPS adjusted slightly negative, but setting it to 0% if fairly easy with datalogging. Otherwise aim for 0.45V.