removing 3000 rpm limiter...HOW? - Ranger-Forums - The Ultimate Ford Ranger Resource


4.0L OHV & SOHC V6 Tech General discussion of 4.0L OHV and SOHC V6 Ford Ranger engines.

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Old 04-12-2009
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removing 3000 rpm limiter...HOW?

since i swapped engines i have had a problem with my truck trying to stall out and buck at 3000 rpms, while in all running gears. if i gun it it will go past the limiter of 3000 rpms but that is a pain in the *** when i am usually changing gears at a higher rpm. how do i remoeve or disable this annoyance myself w/o having to pay out the *** for a new computer?
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Old 04-12-2009
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Did you swap in a computer from an auto? It thinks it's not in gear I guess.
Are you sure that is the problem though, if it sometimes lets you go past it?
A programmer/tuner can remove the rev limited.
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Old 04-12-2009
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i got the engine from a junk yard w/no computer. where do i get a programmer / tuner? ebay sucked trying to find a chip that would do the job.
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Old 04-12-2009
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i think the only way to do it is with a tuner and it will only go to 4100 with a sct tuner......
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Old 04-12-2009
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Quote:
Originally Posted by jaksback View Post
if i gun it it will go past the limiter of 3000 rpms...
If you can drive through it, it is not a PCM rev limiter. You have some other problem.

What year is the truck, what was year/displacement of the original engine, what year/displacement is the replacement engine and which PCM is in there now?
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Old 05-06-2009
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it was a 99 4l and i replaced it w'98 4l. i still have the 99 pcm in there. when i disconnect the cam shaft tdc sensor the problem goes away but then my timing sux and engine tappets under strain.
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Old 05-06-2009
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The Camshaft Position sensor (CMP) changed from a Hall Effect (3-pin) in 1998 to a Variable Reluctance Sensor (2-pin) in 1999. The CMP sensor and the engine harness must match the year of the PCM.

If you have the correct combination of sensor, harness and PCM, then check to see if the CMP is timed correctly to the camshaft.
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Old 05-07-2009
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it has the 99 2-pin cpm that matches the pcm thats in there, nothing has been mismatched in the swap electronically, even have the original throttle body right down to the each sensor.....what if the throttle position sensor has a glitch in it. would that make it do the jump at 2900-300- rpm? i tested it with a voltometer and there was a small glitch in the readout at just about the position the throttle would be when this crap happens.
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Old 05-07-2009
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The TPS should smoothly increase in voltage as the throttle is opened. There should be no flat spots or reversals.
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Old 05-08-2009
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i willp go buy a new one and get back as to the results
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Old 05-29-2009
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it turns out that it was he synchro/camshaft sensor going bad.
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Old 05-29-2009
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i think my 06' has something like that on it...

if im just seitting at idle and i rev it up, it chokes at 3000rpm.... but when im driving and i give it gas itll go past 3000 rpm just fine....how do you go about getting past the limiter, i want mine off!
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Old 05-29-2009
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Quote:
Originally Posted by dixie_boysles View Post
if im just seitting at idle and i rev it up, it chokes at 3000rpm.... but when im driving and i give it gas itll go past 3000 rpm just fine....how do you go about getting past the limiter, i want mine off!
Thats the stock rev limiter, to remove it you have to get a tuner.
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Old 05-29-2009
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^^^^What he said. Its put there to protect the tranny in case you decide to be cool guy and do a neutral drop burnout.
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Old 05-29-2009
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well then, i guess itll just have to stay limited at 3000 rpms then...
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Old 05-31-2009
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nah just do like i did--unplug the damn sensor....runs great since i did....
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