Throttle position sensor

[BoostingGT]

2010 LGT 28,400 Miles

 

My friend hookup his logger to my car on a trip to Ohio. We looked over everything and one thing stood out as a problem. The throttle position would never reach over 50% when I had the pedal to the metal. I am not sure if the logger needed to know what voltage will equal 100% throttle. I haven't bought the service manual yet and wanted to know if these car run a 5V system for pedal position sensor or if anyone knew if this is adjustable like the older system that had the senor mounted to the throttle body.

 

Thanks,

 

Victor

[FLlegacy]

The throttle is controlled by the ecu, keeping the throttle open only partially allows the manifold pressure to remain constant and give a more linear pull instead of like previous LGT models. It isn't a problem, that is simply the way it is. Maybe one of the forum tuners could explain it better, but it isn't something you should be keen on messing with, since you don't understand the logic behind its programming.

[Rutchard]

Stock tune? ECU doesn't let the throttle open anywhere close to 100% until at least 3rd gear. Go stage 1 and that sucker will open up much much earlier.

[GTEASER]

Yep. My tuner is the guy that developed Cobb's Stage 1 OTS maps for the 2010 GT because his wife owned one. He found that even at WOT, the throttle plate would only be at 48% on the stock tune. It was something he had never seen before but said that Subaru did that on the stock tune to smooth out the powerband for the layperson who was buying the car off the showroom floor. Get on the Cobb Stage1 tune or a custom tune, you don't want to mess with that yourself. It is tied to load, fueling, timing, boost, wgd, etc tables in the map.

 

On a side note....our gains going Stage1 are so significant, that it's no wonder that Subaru detuned (neutered) our motors so much. They can't have the giant family sedan of the livery giving the boy racer flagship STi a run for it's money.

[BoostingGT]

[but it isn't something you should be keen on messing with, since you don't understand the logic behind its programming.]

I am not trying to tune or modify anything. I just need to know if there is an adjustment. Say what your want but there are voltages ranges for everything that the ECU needs to see. When these ranges are off it totally screws up what the ECU thinks is happening.

 

On an non-drive-by-wire-system once you got WOT and the TPS will read 5 volts no matter what. That voltage can read wrong if the TPS sensor is not adjusted properly. The adjustment is usually set at closed throttle position, voltage should read 0.48-0.52 volts at closed throttle. Once that adjustment is made the voltage should read 5.0 Volts at WOT. This means 5 volts = 100% throttle. This is something that is known to be off from the factory. You can look at logs all you want but the percentage is based on volts that goes for drive-by-wire also.

 

[stock tune? ECU doesn't let the throttle open anywhere close to 100% until at least 3rd gear. Go stage 1 and that sucker will open up much much earlier.]

I logged the car on the highway in 3rd gear. It never reached 100% throttle up to about 4.5K RPM. Thanks this is useful information!

 

[My tuner is the guy that developed Cobb's Stage 1 OTS maps for the 2010 GT because his wife owned one. He found that even at WOT, the throttle plate would only be at 48% on the stock tune. It was something he had never seen before but said that Subaru did that on the stock tune to smooth out the powerband for the layperson who was buying the car off the showroom floor.]

Really great information this would explain the 50% max throttle. It also explains why the car does not hit hard when I go WOT. I personally think it sucks and like the power instantly. Its a shame because it defeats the purpose of a smaller turbo spool up.

 

Thanks guys this makes me feel better. I have had problems with the car and now I am paranoid that the previous owner or dealer messed it up. The car is very clean and nice but buying a used car is really buying someone else's problems.

 

If anyone knows the conditions needed to log 100% throttle please let me know. I would feel better seeing 100% throttle.

 

Thanks again!

Victor

[GTEASER]

Get a Cobb AccessPort V3. You can log anything and everything you want easily and even view it in real time.

 

What are these "problems" you are having? We're here to help.

[FLlegacy]

Get a Cobb AccessPort V3. You can log anything and everything you want easily and even view it in real time.

 

What are these "problems" you are having? We're here to help.

 

I believe his problem is he is not seeing 100% throttle

 

 

 

Victor, I well understand the adjustments involved with a tps, but as I and others have pointed out that is not the case here. The throttle is completely ecu controlled, you will have to get a tune to see 100% throttle.