I have a -timing reading and hesitation when opening throttle quickly, it is better when slowly accellerating. Where do i look to tune this out, im considering HPTuners, is this a common problem on certain year trucks?
I have 5.3 with some work done, but this condition was there stock. Is this torque management?

 

Ive never had this issue. Can you attach your tune or send it to me? I can look at it. My friend's 99 camaro did the same thing.. not as drastic as yours to where it would dip negative, but it would retard the timing back as far as 10* w/o throwing any KR. Is it throwing any KR? My email is sslow48@hotmail.com if you want to send it.

 

I dont record knock retard as this happens from a dead stop launch, but the truck see's about 4 to 5* KR in second gear at times and third. I have Tuner Cat tune in the PCM form a friend back east. I have no way of changing it, so i was contemplating HPtuners to go after this problem. Does timing from the factory cause burst knock KR or could this be to minimize abuse you think? Thanks for chiming in.

 

Theres torque management, burst knock, false knock.. all kinds of stuff tuned into the factory tunes that will limit power. But it going negative on a quick and hard launch or fast throttle is odd to me, i know some of the newer vehicles have negative timing tuned in, just for safety purposes. I'm sure with a hptuners uploaded file, you or someone will be able to figure it out pretty quickly.

 

The 99 PCM's were known for false knock problems, I had it with mine after my cam swap. I'd see 7.9* of KR every time I touched the throttle. Back then, the solution was to swap in an 01-02 PCM and that took care of the problem. Now I believe that you can just flash in the newer operating system and tune the PCM and the problem will be solved.

 

alot of times the processor in the 99pcms will die if you try that i think?

 

Flashing a 01-02 op on a 99-00 pcm is still up in the air, some say they have done with success, other say it didn't work. I'd just get a 01-02 pcm... Or start tuning the crap out of the pcm you have now.. BTW if you do upgrade to the 01-02, you will loose the dual v.e tables, and gain about 12 trans adapt tables. A very wise upgrade IMHO.

 

I flashed my stock PCM with an 02 file. No damage on mine. After working with both the 99 and 02 tunes, heads up the 02 tune is much better. I haven't found anyone that has had there pcm zapped by upgrading the files. If so please include a link or some sort of proof instead of hearsay. Not trying to be a dick, I would just like to hear from someone this has happened to.

 

Thanks for all the replys, can you tell me what drawbacks there are to just using latest HP tuners software to fix my 99 pcm tune? It works decent in every way except this quick throttle timing retard problem. Anyone?