Will a nelson tune require me to do a crank relearn on my n/a 4.8 with bolt ons and stock cam?

Thanks,
Derek

 

some trucks need it and some dont...its just kinda a luck of the draw type thing. ive replaced my PCM 3x and never had to do the relearn. some dont get away with it. you probably wont need it but always plan on it just incase

 

my first nelson needed a relearn, but the 2nd didnt.. so go figure

 

There's no rhyme or reason to it. Luck of the draw I guess. I needed one, tried the crank relearn and no luck. It turned out to be a bad CKP sensor.

I have needed a relearn though, and it ran like poop above about 4000rpm.

I think if you have a 99-00 and you go with an 02 PCM, you will need a relearn though.

 

I just changed from a tuned 2000 PCM to a tuned 2002 PCM on my truck and no relearn was needed. Once again, it's just a crap shoot...I have had 5 different tunes and only #2 required the relearn.

 

I didn't have a crank relearn code pop immediatly after the install of my tune, but 2-3 months later I had the code. Relearn is done and haven't had any more problems.

 

how is the crank relearn done?

 

scan tool is the only way i know to do it.

 

I think you have to go to a mechanic or a dealer to do it. Anyone with a mod comp. You hook the Computer up to the truck and rev the engine a couple of times and it fixes it. I THINK its the position sensor for the timing and where the crank and camshaft is. If the timing is adjusted any amount it senses an error with the sensor. I really dont know though, it just makes sense to say thats what it is.

Derek

 

HP Tuners, Tech II and I think EFI live can all do it.