ToxicWS6

i have an lq4 stock short block with stock cam in it, all i did was drop 799 heads on it to up the CR.

i recently swapped this into an 1987 K5 blazer with a 4l80E behind it, its stock truck intake manifold with swap headers on it and 799 heads on all stock lq4, engines out of a 1999/2000 2500hd, transmissions out of a 2002 2500HD and the harness is from a 2001 2500hd and the ECU is from a 2001 1500 5.3L

i already ran into an issue with wrong injector data and im pretty sure i got that fixed by looking at the tune on another vehicle and trying different injector flow rate, but if anyone can tell my what exact LB/hr injectors are on a 1999/2000 2500hd id appreciate it, ECU had 24.8lb injectors and i put it to 21.8LB injectors as thats what my friends tune had and it seems to run way better, doesnt fall on its face anymore.

also for starting to tune it and all, would running the factory VE tables for a stock lq4 be very close because it being the same cam and basic same flow rate heads, just more CR?

for SD mode i should have STFT and LTFT turned off/disabled fully or should i be running on STFTs only?

im still working out my transmission tuning and all which im hoping once this rain cuts back i can test it out and should be good.

ive had runnning issues with it and just want to make sure i got all my swap stuff on the same playing field and all and was just seeing if you guys may know of something i missed, thanks!

also truck is on stock OS set in SD mode, i set my friends LS 4.8L all stock long block in his k5 blazer swap like this and he has no issues, which is why this is throwing me a little, im 98% sure when i tuned in my WS6 i have STFT on but i also have a 2 bar OS on that car vs the factory OS system, i know i have some things on my tune i need to tweak after i did some reading around but i just wanted to see if you all had any input on this or see something i may of missed or didnt think of, thanks!

Always2Slow

iTrader: (8)

Well for starters what I would do is not go into SD mode with a setup that doesn't need SD mode. Add 7% to the whole VE table and MAF calibration table. Can you get the part number off the injectors? You can't guess on that data. The factory OS is more than capable of handling a large majority of setups.

ToxicWS6

the reason i did SD mode was for the lack of MAF sensor and i figured it was a less complicated way to tune it/getting it to run fine for a basic build.

ill try to get part numbers off the injectors today and see if i can google it and find them or ill post them on here, why i didnt think about that idk lol.

this transmission tuning is throwing me off, think i just need to slow down and go through it all one at a time too.

thanks!

fire67bird

I would copy the VE and timing tables over from a factory tune that came with those heads originally. Also it's critical to get the right injector data in there like the other guy said.