Ok...I recently did a head's and cam package on a 1999 silverado 5.3 liter truck...well before the heads and cam package this was THE SLOWEST 5.3 truck iv'e ever ridden in..felt like it was pulling 50* timing lol...Anyways..I figured hell head's and cam should wake it up...well it did..but only marginaly..so we go off to the dyno...after head's,cam,longtubes,!cat's and a cold air intake it made a whopping 201 RWHP and 196 RWT!! exciting huh? lol....well it was pulling 8* KR all the time under WOT and only showing a total of 9*!! well I broke out the diablo tuner for it and enriched it by 5% and added 10% timing...the truck feel's 1000 times better..but still only getting 18* timing under WOT and 3* KR....so I unplugged the knock sensor harness and took it back out...0 KR and 22* total timing...now we are getting somewhere...ok really good timing all the way through 1st gear...then when I shift to 2nd it drops to 7* for a split second then back up to 22*...but still no KR..what's up with that? lol...also..just cruising around it get's 33-35* then when i nail it, it goes to 22* but the second i let off of the gas from flooring it timing jumps to 45-46*..but only for a split second.. is that normal? any help would be apreaciated...OH and the knock sensor wiring harness is bad too..it's literally burnt somehow.....I replaced both knock sensors but not the harness..and it keep's throwing a knock sensor code..here is all the codes i am getting...P0300,P0327,P0332, and P0405...ANY help would be very nice oh and the truck has a constant 14.3:1 A/F ratio...every time i add fuel it get's more timing..but get's slower as well..Thank's,

Carter

 

The a/f at cruise should be 14.7. Have you autotaped it or efi live to see what the ltrims are or any wot a/f ratio information. Under wide open throttle you want it to be 12.9-13.1. Hard to tell whats going on without any logged info to relate what the computer is doing. If the mixture is off, or the timing is low it can kill power big time. Have you tried some 100 octane gas to see if it still knocks.

 

Stroked,

I meant the A/F is 14.3:1 at WOT lol...really lean..so I added 5% fuel and it fixed it along with adding 10% timing...ok BUT now a new problem arose everything was perfect...just took it for a loooong drive....it was fine 22* timing at WOT 0 KR.....well I turned around and started heading back to my house..9.0 KR and -7* total timing!! I turned it off and re-loaded the predator custom program I made...now it's perfectly fine again..I wonder if it is learning it back out or something?..it has to be what can I do to get rid of this?...I need edit lol...Thank's,

Carter

 

You just need to toss away the Preditor and get Edit.I've tuned many 4.8-6.0 trucks and they all need more fuel and timing.Ussually the L-terms are way out of whack after H/C installs and the trucks have low timing to start with.Also torque management deletion helps on the shifts.I found that the preditor doesn't delete everything needed.

 

woah now dont toss it, just get a custom tune, same damn thing as edit but u dont have to deal with tuning it yourself. and another thing, check out a post on here about octane tables, all that knock u are getting is causing timing to be pulled out on a regular basis...from what i read, its a good article and dont throw the predator away, just tell a tuner what your deal is and they will fix it to wre u can adjust the parameters and have it change and dial in better