bad gas pedal ? WTF.....
09-06-2013, 11:00 AM
#11
09-06-2013, 12:40 PM
#12
2nd Gear Member
Thread Starter
Join Date: Oct 2012
Location: NC
Posts: 205
I'm glad all you internet master mechanics are so quick to condemn a real mechanic because you don't understand how you car works. Let me explain.
The Accelerator Pedal Position sensor employs potentiometers to determine how far down you have the pedal pressed and in some models how hard you pressed it. These sensors are relatively simply with a power wire going into a coil a ground on the other side and a signal wire that "wipes" across them with the motion of the pedal. As you move the wiper the resistance of the circuit changes because you either shorten or lengthen the path to ground. This voltage signal is how the car knows where the throttle pedal is.
During normal operation your foot will hold the pedal in about the same spot a lot because it takes the same amount of input to cruise at 45 mph. This is usually at the top of the pedal travel Constantly being in this position causes what is called a "flat spot" in the sensor" or an area where it no longer reads. It used to happen to a vehicles TPS now it is also common in the APP. When the sensor malfunctions in this way the vehicle will hesitate because as the pedal moves through that position it has no idea you're applying the throttle until you pass the "flat spot."
You said you had this problem before the blower install and tune. So #1 you're an idiot for putting a supercharger on a car that wasn't running 100% plain and simple. #2 if you had the problem before, you had the problem before and it isn't the tune.
The Accelerator Pedal Position sensor employs potentiometers to determine how far down you have the pedal pressed and in some models how hard you pressed it. These sensors are relatively simply with a power wire going into a coil a ground on the other side and a signal wire that "wipes" across them with the motion of the pedal. As you move the wiper the resistance of the circuit changes because you either shorten or lengthen the path to ground. This voltage signal is how the car knows where the throttle pedal is.
During normal operation your foot will hold the pedal in about the same spot a lot because it takes the same amount of input to cruise at 45 mph. This is usually at the top of the pedal travel Constantly being in this position causes what is called a "flat spot" in the sensor" or an area where it no longer reads. It used to happen to a vehicles TPS now it is also common in the APP. When the sensor malfunctions in this way the vehicle will hesitate because as the pedal moves through that position it has no idea you're applying the throttle until you pass the "flat spot."
You said you had this problem before the blower install and tune. So #1 you're an idiot for putting a supercharger on a car that wasn't running 100% plain and simple. #2 if you had the problem before, you had the problem before and it isn't the tune.
I am gonna drive it today and tomorrow and see how she runs and will let you guys know. I appreciate your feedback
09-06-2013, 01:54 PM
#13
Gentleman's Relish
Join Date: Feb 2005
Location: AZ
Posts: 13,090
http://mustangcollective.com/showthread.php?t=11707
Link to a thread on another forum about the throttle by wire/drive by wire system on S197 stangs.
All the tune did was increase the registered voltage or reduce the threshold voltage of this sensor to make the PCM respond sooner. It doesn't actually solve the problem.
The fix in the thread addresses the hardware issue...never tried it myself nor would I since a mistake could either damage the sensor or make the throttle too sensitive.
Link to a thread on another forum about the throttle by wire/drive by wire system on S197 stangs.
All the tune did was increase the registered voltage or reduce the threshold voltage of this sensor to make the PCM respond sooner. It doesn't actually solve the problem.
The fix in the thread addresses the hardware issue...never tried it myself nor would I since a mistake could either damage the sensor or make the throttle too sensitive.
09-06-2013, 01:56 PM
#14
2nd Gear Member
Join Date: Aug 2009
Location: Somewhere in southern Indiana
Posts: 178
A reset on the pedal? I work on these every day and am not aware of any kind of reset on the pedal. Like Steve said earlier, it is a potentiometer like a volume **** on your stereo. Some of the older ones had three channels refered to as APP 1,2,and 3 on the pid inputs. The newer ones only have 2. Have someone with the equipment look at the PIDS for you, and you will see that most likely one of the 3 is starting to go bad, or have a dead spot in it. It is not uncommon to eventually get a dead spot just past tip in on an accelerator pedal. When it does this, consider it your warning before it goes totally out.
09-06-2013, 02:04 PM
#15
Gentleman's Relish
Join Date: Feb 2005
Location: AZ
Posts: 13,090
A reset on the pedal? I work on these every day and am not aware of any kind of reset on the pedal. Like Steve said earlier, it is a potentiometer like a volume **** on your stereo. Some of the older ones had three channels refered to as APP 1,2,and 3 on the pid inputs. The newer ones only have 2. Have someone with the equipment look at the PIDS for you, and you will see that most likely one of the 3 is starting to go bad, or have a dead spot in it. It is not uncommon to eventually get a dead spot just past tip in on an accelerator pedal. When it does this, consider it your warning before it goes totally out.
First post in the thread has the procedure.
Does it work? I've tried it and I think I noticed a bit less lag. Only way to know for certain would be if I could go back to the 'before' setting and do a back-to-back comparison.
09-06-2013, 02:27 PM
#16
6th Gear Member
09-06-2013, 02:31 PM
#17
2nd Gear Member
Join Date: Aug 2009
Location: Somewhere in southern Indiana
Posts: 178
I will check with a powertrain engineer and let you know. I don't think that this does anything. In order for the pcm to relearn its adaptive perameters, the keep alive memory must be reset. This is accopmpished with either a dealer IDS tool, or by disconnecting the battery for about 20 minutes. I won't be at my home plant next week, so it will be the week after before i post back.
09-06-2013, 02:56 PM
#18
Gentleman's Relish
Join Date: Feb 2005
Location: AZ
Posts: 13,090
That would be interesting to find out if it's real or not. This has been around for a few years....
The only reason I am skeptical of it (even though I think it did something) is because most cars will indicate whether said adjustment has been taken or not.
There is no indication at the end of the process to confirm anything.
The only reason I am skeptical of it (even though I think it did something) is because most cars will indicate whether said adjustment has been taken or not.
There is no indication at the end of the process to confirm anything.
09-06-2013, 08:35 PM
#19
2nd Gear Member
Thread Starter
Join Date: Oct 2012
Location: NC
Posts: 205
I'm glad all you internet master mechanics are so quick to condemn a real mechanic because you don't understand how you car works. Let me explain.
The Accelerator Pedal Position sensor employs potentiometers to determine how far down you have the pedal pressed and in some models how hard you pressed it. These sensors are relatively simply with a power wire going into a coil a ground on the other side and a signal wire that "wipes" across them with the motion of the pedal. As you move the wiper the resistance of the circuit changes because you either shorten or lengthen the path to ground. This voltage signal is how the car knows where the throttle pedal is.
During normal operation your foot will hold the pedal in about the same spot a lot because it takes the same amount of input to cruise at 45 mph. This is usually at the top of the pedal travel Constantly being in this position causes what is called a "flat spot" in the sensor" or an area where it no longer reads. It used to happen to a vehicles TPS now it is also common in the APP. When the sensor malfunctions in this way the vehicle will hesitate because as the pedal moves through that position it has no idea you're applying the throttle until you pass the "flat spot."
You said you had this problem before the blower install and tune. So #1 you're an idiot for putting a supercharger on a car that wasn't running 100% plain and simple. #2 if you had the problem before, you had the problem before and it isn't the tune.
The Accelerator Pedal Position sensor employs potentiometers to determine how far down you have the pedal pressed and in some models how hard you pressed it. These sensors are relatively simply with a power wire going into a coil a ground on the other side and a signal wire that "wipes" across them with the motion of the pedal. As you move the wiper the resistance of the circuit changes because you either shorten or lengthen the path to ground. This voltage signal is how the car knows where the throttle pedal is.
During normal operation your foot will hold the pedal in about the same spot a lot because it takes the same amount of input to cruise at 45 mph. This is usually at the top of the pedal travel Constantly being in this position causes what is called a "flat spot" in the sensor" or an area where it no longer reads. It used to happen to a vehicles TPS now it is also common in the APP. When the sensor malfunctions in this way the vehicle will hesitate because as the pedal moves through that position it has no idea you're applying the throttle until you pass the "flat spot."
You said you had this problem before the blower install and tune. So #1 you're an idiot for putting a supercharger on a car that wasn't running 100% plain and simple. #2 if you had the problem before, you had the problem before and it isn't the tune.
http://www.oreillyauto.com/site/c/de...2183&ppt=C0033
09-06-2013, 08:38 PM
#20
2nd Gear Member
Thread Starter
Join Date: Oct 2012
Location: NC
Posts: 205
That would be interesting to find out if it's real or not. This has been around for a few years....
The only reason I am skeptical of it (even though I think it did something) is because most cars will indicate whether said adjustment has been taken or not.
There is no indication at the end of the process to confirm anything.
The only reason I am skeptical of it (even though I think it did something) is because most cars will indicate whether said adjustment has been taken or not.
There is no indication at the end of the process to confirm anything.