Throttle Position Absolute Percentage?
08-29-2007, 09:34 PM
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Throttle Position Absolute Percentage?
Obviously the absolute throttle position percentage isn't 0 when you're not on the pedal because of the throttle plate stop screw - so it's generally around 10% - but that's irrelevant - when you open the butterfly all the way, shouldn't it read 100%?
Why doesn't it?
On 3 different cars I've tried - 2 with perfectly operational TPS's they both top out at like 80%.
Can anybody explain this to me?
Why doesn't it?
On 3 different cars I've tried - 2 with perfectly operational TPS's they both top out at like 80%.
Can anybody explain this to me?
08-30-2007, 12:06 AM
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Re: Throttle Position Absolute Percentage? (Syndacate)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Syndacate »</TD></TR><TR><TD CLASS="quote">Obviously the absolute throttle position percentage isn't 0 when you're not on the pedal because of the throttle plate stop screw - so it's generally around 10% - but that's irrelevant - when you open the butterfly all the way, shouldn't it read 100%?
Why doesn't it?
On 3 different cars I've tried - 2 with perfectly operational TPS's they both top out at like 80%.
Can anybody explain this to me?</TD></TR></TABLE>
TPSes can be calibrated. There's a slot. You slide it back and forth in the slot. It should be very close to 0 at closed throttle (10% throttle is HUGE ...unacceptable for idle). Since the throttle plate opens up 90 degrees, 10% would be 9 degrees. You car would idle at 6k if the plate was actually that far open at idle. Maybe the TPS was off calibration.
It should read 100% at WOT (obviously). That's around iduno...4.7? 4.8 volts?? somewhere in that region. Real close to 5 volts.
Why doesn't it?
On 3 different cars I've tried - 2 with perfectly operational TPS's they both top out at like 80%.
Can anybody explain this to me?</TD></TR></TABLE>
TPSes can be calibrated. There's a slot. You slide it back and forth in the slot. It should be very close to 0 at closed throttle (10% throttle is HUGE ...unacceptable for idle). Since the throttle plate opens up 90 degrees, 10% would be 9 degrees. You car would idle at 6k if the plate was actually that far open at idle. Maybe the TPS was off calibration.
It should read 100% at WOT (obviously). That's around iduno...4.7? 4.8 volts?? somewhere in that region. Real close to 5 volts.
08-30-2007, 06:24 AM
#3
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Re: Throttle Position Absolute Percentage? (B serious)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B serious »</TD></TR><TR><TD CLASS="quote">It should be very close to 0 at closed throttle (10% throttle is HUGE ...unacceptable for idle). Since the throttle plate opens up 90 degrees, 10% would be 9 degrees. You car would idle at 6k if the plate was actually that far open at idle. Maybe the TPS was off calibration.
It should read 100% at WOT (obviously). That's around iduno...4.7? 4.8 volts?? somewhere in that region. Real close to 5 volts.
</TD></TR></TABLE>
Not quite...
The throttle should NEVER be allowed to go perpendicular to the bore. Allowing it to do so will eventually round it out and cause a vaccum leak. So it is offset using the throttle stop screw (which should never be touched). Indeed a scantool should read <9.8% (in the Helms) at idle.
As for the WOT reading: Manually open it all the way by hand. What the scantool reads is what it reads. It shouldn't go much above 4.5v anyway.
All the TPS has to do is a) let the ECU know when to idle and use the fuel-cut-on-decel b) let the ECU know the rate of change in throttle position and c) let the ECU know when it's at WOT.
It should read 100% at WOT (obviously). That's around iduno...4.7? 4.8 volts?? somewhere in that region. Real close to 5 volts.
</TD></TR></TABLE>
Not quite...
The throttle should NEVER be allowed to go perpendicular to the bore. Allowing it to do so will eventually round it out and cause a vaccum leak. So it is offset using the throttle stop screw (which should never be touched). Indeed a scantool should read <9.8% (in the Helms) at idle.
As for the WOT reading: Manually open it all the way by hand. What the scantool reads is what it reads. It shouldn't go much above 4.5v anyway.
All the TPS has to do is a) let the ECU know when to idle and use the fuel-cut-on-decel b) let the ECU know the rate of change in throttle position and c) let the ECU know when it's at WOT.
08-30-2007, 06:47 AM
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Re: Throttle Position Absolute Percentage? (EE_Chris)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EE_Chris »</TD></TR><TR><TD CLASS="quote">
Not quite...
The throttle should NEVER be allowed to go perpendicular to the bore. Allowing it to do so will eventually round it out and cause a vaccum leak. So it is offset using the throttle stop screw (which should never be touched). Indeed a scantool should read <9.8% (in the Helms) at idle.
As for the WOT reading: Manually open it all the way by hand. What the scantool reads is what it reads. It shouldn't go much above 4.5v anyway.
All the TPS has to do is a) let the ECU know when to idle and use the fuel-cut-on-decel b) let the ECU know the rate of change in throttle position and c) let the ECU know when it's at WOT.</TD></TR></TABLE>
I was using a scan tool.
No, my Tercel TPS is ***-raped, but it's only sometimes - so I was just checking out the TPS and I got those numbers (about 14% closed and about 80% WOT) w/ a scanner. So I said just for ***** and giggles I tested out my dad's '00 Jetta GLS and my '97 Civic EX and I got the same results.
The ~10% I can see at idle....but I expected it to be about 100% when you flp the butterfly all the way open, no?
It reads in percentages, not volts. I'm just wondering why when you pull the butterfly all the way to the stopper, it stops at ~80% - on multiple vehicles.
Not quite...
The throttle should NEVER be allowed to go perpendicular to the bore. Allowing it to do so will eventually round it out and cause a vaccum leak. So it is offset using the throttle stop screw (which should never be touched). Indeed a scantool should read <9.8% (in the Helms) at idle.
As for the WOT reading: Manually open it all the way by hand. What the scantool reads is what it reads. It shouldn't go much above 4.5v anyway.
All the TPS has to do is a) let the ECU know when to idle and use the fuel-cut-on-decel b) let the ECU know the rate of change in throttle position and c) let the ECU know when it's at WOT.</TD></TR></TABLE>
I was using a scan tool.
No, my Tercel TPS is ***-raped, but it's only sometimes - so I was just checking out the TPS and I got those numbers (about 14% closed and about 80% WOT) w/ a scanner. So I said just for ***** and giggles I tested out my dad's '00 Jetta GLS and my '97 Civic EX and I got the same results.
The ~10% I can see at idle....but I expected it to be about 100% when you flp the butterfly all the way open, no?
It reads in percentages, not volts. I'm just wondering why when you pull the butterfly all the way to the stopper, it stops at ~80% - on multiple vehicles.
11-04-2009, 01:43 PM
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Re: Throttle Position Absolute Percentage?
11-04-2009, 07:34 PM
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Re: Throttle Position Absolute Percentage?
haha okay. im having diffculties checking the voltage because my meters only reads 6v 9v and 12v and i think its supposed to be 20v... so idk maybe if someone knows what 12v is supposed to read at that can help.
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