TJ Tatum
Member
Can the rev limiter be reset or taken off?
Tater
Tater
Can the rev limiter be reset or taken off?
- Thread starter TJ Tatum
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Tim Turner
Well-Known Member
The only way that I know of removing it is to buy a flasher from Wayne Foy. Not only can you remove the rev limiter, but it can firm up your shift points, improve gas efficiency, remove speed limiter, adjust speedo for larger tires, etc.
Tater,
The Rev limiter is only active when the vehicle is in park or neutral and protects the engine from reving past 3000 RPM with no load
Are you sure you are not wanting to remove the "Speed Limiter" which is set to 97 MPH?
...Rich
The Rev limiter is only active when the vehicle is in park or neutral and protects the engine from reving past 3000 RPM with no load
Are you sure you are not wanting to remove the "Speed Limiter" which is set to 97 MPH?
...Rich
Wayne Foy
Active Member
Tater,
Shoot me an email with your questions sir. I will be more than happy to answer them for you.
Shoot me an email with your questions sir. I will be more than happy to answer them for you.
LB
Active Member
Rich. Speed limiter is 97mph? No way. I do 110 or so all the time without hitting the speed limiter. I end up hitting terminal velocity before the engine cuts out.
Daniel,
Some early model 2001 Sport Trac's did not have the Speed Limiter set when they left the factory. Ford send out a recall letter that the Auto-transmission output shaft bearings could fail if the vehicle was operated at sustained speeds in excess of 97 mph.
My original 2001 Sport Trac did not have the Speed Limiter set and I could exceed 105 mph.
Whenever the owner would take their vehicle back to Ford for any servicing, they would reset the speed limiter to 97 MPH.
All vehicles from the factory have that 97 MPH speed limiter except a few early 2001's that have never made it back to the dealer.
The only way to remove the speed limiter is to add a chip to the PCM or hace the PCM reprogrammed.
If your 2004 model is factory stock, you will not be able to exceed 97 MPH, except going down a steep hill, or you have changed your tire size and getting a lot of speedometer error.
Or perhaps you bought the vehicle used and the previous owner had the PCM reprogrammed or has installed a performance chip.
...Rich
Some early model 2001 Sport Trac's did not have the Speed Limiter set when they left the factory. Ford send out a recall letter that the Auto-transmission output shaft bearings could fail if the vehicle was operated at sustained speeds in excess of 97 mph.
My original 2001 Sport Trac did not have the Speed Limiter set and I could exceed 105 mph.
Whenever the owner would take their vehicle back to Ford for any servicing, they would reset the speed limiter to 97 MPH.
All vehicles from the factory have that 97 MPH speed limiter except a few early 2001's that have never made it back to the dealer.
The only way to remove the speed limiter is to add a chip to the PCM or hace the PCM reprogrammed.
If your 2004 model is factory stock, you will not be able to exceed 97 MPH, except going down a steep hill, or you have changed your tire size and getting a lot of speedometer error.
Or perhaps you bought the vehicle used and the previous owner had the PCM reprogrammed or has installed a performance chip.
...Rich
LB
Active Member
Rich,
I honestly can't tell you whether my PCM has been reprogrammed or not. I bought my '04 Trac in July '04. It was a dealer's promo with only 4000 miles on it. It had been used by a driver's education class at a local high school.
Alright... now for a lesson in rev limiters. "Make me as smart as Rich." My buddy is telling me that a rev limiter's purpose is to stop your engine from going too high in the revs. Is that correct? He says the only time I will hit that is when I am in the highest gear or neutral, or park. In N or P the rev limiter is set to 3000, correct?
Being that this truck was previously used as a vehicle to teach students how to drive *safely* in, I would assume that the PCM was not reprogrammed.
What I can tell you is that I can exceed 97mph (110+, was too scared to look down, haha) on a straight strip with no elevation increase or decrease, and I have not messed with anything in the computer.
Maybe my Trac is special
Daniel
I honestly can't tell you whether my PCM has been reprogrammed or not. I bought my '04 Trac in July '04. It was a dealer's promo with only 4000 miles on it. It had been used by a driver's education class at a local high school.
Alright... now for a lesson in rev limiters. "Make me as smart as Rich."
My buddy is telling me that a rev limiter's purpose is to stop your engine from going too high in the revs. Is that correct? He says the only time I will hit that is when I am in the highest gear or neutral, or park. In N or P the rev limiter is set to 3000, correct?Being that this truck was previously used as a vehicle to teach students how to drive *safely* in, I would assume that the PCM was not reprogrammed.
What I can tell you is that I can exceed 97mph (110+, was too scared to look down, haha) on a straight strip with no elevation increase or decrease, and I have not messed with anything in the computer.
Maybe my Trac is special
Daniel
Wayne Foy
Active Member
its possible that it was tampered with. If you put the ST in neutral, rev the engine. If it goes over 3100 rpms, you have been chipped or flash tuned.
As far as rev limiters, there are actually 3 in the programming.
1. Neutral Limit - set at factory to 3100
2. RPM Vs Torque - limiter hits once you reach a set RPM, Factory rev limit is set at 6250 in gear
3. Speed Vs Torque - limiter hits once you reach set speed, factory speed limiter is set to 94 mph on 04 KRN0-KRN2 PCM codes.
I know my 04 ST stock would shut down at around 98, so thats the amount my speedo was off from the factory as well.
There are variables of the above I can adjust for situations, like a 2 step drag launch, but besides that, those are the mains.
As far as rev limiters, there are actually 3 in the programming.
1. Neutral Limit - set at factory to 3100
2. RPM Vs Torque - limiter hits once you reach a set RPM, Factory rev limit is set at 6250 in gear
3. Speed Vs Torque - limiter hits once you reach set speed, factory speed limiter is set to 94 mph on 04 KRN0-KRN2 PCM codes.
I know my 04 ST stock would shut down at around 98, so thats the amount my speedo was off from the factory as well.
There are variables of the above I can adjust for situations, like a 2 step drag launch, but besides that, those are the mains.
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Daniel,
The Rev limiter limits the engine to 3000 RPM while the transmission is in Park or Neutral. It has nothing to do with speed limiter.
If your truck has the Speed limiter, you will know it when you reach about 100 MPH, you will think your engine shut off. As soon as you lift your foot off the gas the engine runs like normal.
To my knowledge, no factory stock Sport Trac's can exceed the 97 mph limit. Your speedometer may not be as accurate at that speed and may read a little high (100 MPH) but that is not the true speed.
Since I doubt that the PCM was reprogrammed or had the chip changed, your Sport Trac is stock, and thus has the 97 mph speed limiter in place. If you think your speedometer has exceeded 100 MPH, you are only seeing some speedometer error or you were dreaming :lol:
...Rich
The Rev limiter limits the engine to 3000 RPM while the transmission is in Park or Neutral. It has nothing to do with speed limiter.
If your truck has the Speed limiter, you will know it when you reach about 100 MPH, you will think your engine shut off. As soon as you lift your foot off the gas the engine runs like normal.
To my knowledge, no factory stock Sport Trac's can exceed the 97 mph limit. Your speedometer may not be as accurate at that speed and may read a little high (100 MPH) but that is not the true speed.
Since I doubt that the PCM was reprogrammed or had the chip changed, your Sport Trac is stock, and thus has the 97 mph speed limiter in place. If you think your speedometer has exceeded 100 MPH, you are only seeing some speedometer error or you were dreaming :lol:
...Rich
LB
Active Member
Wayne and Rich. Thank you both for the explanations.
Is it likely that they "forgot" to program the speed limiter??? Probably not. Otherwise, I can promise you, even get pictures of my speedometer above 110. I'm not saying that you guys are wrong, but my engine has never hit the speed limiter. I seriously doubt that my speedometer is inaccurate by 16 or so mph.
Is there any way of telling if the PCM was reprogrammed? chip changed? any computer mods? I have not tampered with any of this, nor with performance modifications (exhaust, headers, etc.) so I'm as confused as you are with this one.
Daniel
Is it likely that they "forgot" to program the speed limiter??? Probably not. Otherwise, I can promise you, even get pictures of my speedometer above 110. I'm not saying that you guys are wrong, but my engine has never hit the speed limiter. I seriously doubt that my speedometer is inaccurate by 16 or so mph.
Is there any way of telling if the PCM was reprogrammed? chip changed? any computer mods? I have not tampered with any of this, nor with performance modifications (exhaust, headers, etc.) so I'm as confused as you are with this one.
Daniel
Daniel,
You are only kidding yourself. The PCMs are programmed by computer and rechecked by computer to insure that every bit in the program is set correctly. So it's not like someone when to lunch and forgot to set your speed limited. I would guess that it is pretty near impossible to forget or mis-program.
The only reason any got through without the speed limiter being set is due to fact that Ford did not know there was a problem with the transmission bearing until half way through the model year.
Like Wayne said, someone would have had to tamper with the PCM program to eliminate the speed limiter. I doubt that Ford or the driving school would have done that.
...Rich
You are only kidding yourself. The PCMs are programmed by computer and rechecked by computer to insure that every bit in the program is set correctly. So it's not like someone when to lunch and forgot to set your speed limited. I would guess that it is pretty near impossible to forget or mis-program.
The only reason any got through without the speed limiter being set is due to fact that Ford did not know there was a problem with the transmission bearing until half way through the model year.
Like Wayne said, someone would have had to tamper with the PCM program to eliminate the speed limiter. I doubt that Ford or the driving school would have done that.
...Rich
Wayne Foy
Active Member
Daniel,
Your PCM is located under the hood, over the passenger side of the motor, in the firewall. You will need a 10mm socket, and a deepwell 11mm to remove the PCM. Disconnect the battery first, and then loosen the center 10mm out of the main wiring harness. Once that is loosened and out of the way, use the 11mm deep well to loosen the weather seal around the pcm. Once that is out of the way, wiggle side to side on the PCM and it will come out of the slot. Look at the side opposite of the connector, there will be a hole there with the chip installed, should be taped in, this is if it was chipped. If it was flashed, it will still have the black cover on it with a white sticker with the PCM code on it.
I can definitely tell you without a shadow of a doubt sir:
If your ST goes over 110, and doesnt hit the rev limiter when you rev it in park or neutral, then that PCM has been tampered with after it left the factory.
Your PCM is located under the hood, over the passenger side of the motor, in the firewall. You will need a 10mm socket, and a deepwell 11mm to remove the PCM. Disconnect the battery first, and then loosen the center 10mm out of the main wiring harness. Once that is loosened and out of the way, use the 11mm deep well to loosen the weather seal around the pcm. Once that is out of the way, wiggle side to side on the PCM and it will come out of the slot. Look at the side opposite of the connector, there will be a hole there with the chip installed, should be taped in, this is if it was chipped. If it was flashed, it will still have the black cover on it with a white sticker with the PCM code on it.
I can definitely tell you without a shadow of a doubt sir:
If your ST goes over 110, and doesnt hit the rev limiter when you rev it in park or neutral, then that PCM has been tampered with after it left the factory.
LB
Active Member
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LB
Active Member
I retract my statement.
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