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?

 

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.

 

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.

 

i think the only way to do it is with a tuner and it will only go to 4100 with a sct tuner......

 

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?

 

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.

 

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.

 

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.

 

The TPS should smoothly increase in voltage as the throttle is opened. There should be no flat spots or reversals.

 

i willp go buy a new one and get back as to the results

 

it turns out that it was he synchro/camshaft sensor going bad.

 

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.

 

^^^^What he said. Its put there to protect the tranny in case you decide to be cool guy and do a neutral drop burnout.

 

well then, i guess itll just have to stay limited at 3000 rpms then...

 

nah just do like i did--unplug the damn sensor....runs great since i did....