tuning for bigger injectors?

[Alxsmt]

ok well i read the tutoral on bstuff.com for a turbo gp code but i can only do the idle (i dont have the other things to change?) i also cant get it do idle at all with my bigger injectors in

what exactly do i need to change?

[Joseph Upson]

ok well i read the tutoral on bstuff.com for a turbo gp code but i can only do the idle (i dont have the other things to change?) i also cant get it do idle at all with my bigger injectors in what exactly do i need to change?

Not sure what you found on Beretta com and I wasn't about to join the forum in order to gain use of the search engine. Try this thread, it should help;

http://www.v6z24.com/jbodyforum/how-to-tune-tgp-code-t88684,highlight,tune+tgp+code.html

[Alxsmt]

the same guy posted that on bstuff.com, i think in my xdf its just not called the same same thing or something cuzz i dont have anything that he mentions other than BPC vs. Desired EGR% and i cant even get my car to idle with that and my injectors idle may be another problem but it likes to pulse and stutter when im driving and it doesnt do that with my other injectors

[Superdave]

to adjust for larger injectors you change the 0% value in the "Base Pulse Constant Vs. Desired % EGR" table.

That's the global constant, the stock 3.1 BPC is 224 for 16# injectors.. I have it set to 150 for a friends cammed 3400 running #24 injectors and mine is set to 129 to run the 36lb injectors.


After you change that then you'll have to work over the VE adder table first.. then fine tune the main VE vs RPM vs MAP table.

[Alxsmt]

ok cool, so how do you determin how to change what value to what after you do the global? or is it ovious by just lookin at my wideband and BLMs?

i just noticed the idle VE vs RPM vs MAP. because my car seems to have an idle issue, do you think i could fix that with this table? if so how would you go about doing that?

[Superdave]

since everything is affected by the BPC i'd get that right first.

What size injectors are you using? (i forgot)

[Alxsmt]

they are 28# from the I6 trailblazer engine

so should i be able to get it driveable by just changing the BPC? i couldnt get it after about 45 mins of messing with it, hell my AFR didnt even really change much according to my gauge and the BLMs prettymuch stayed the same too. i started at 150 on the bpc and went clear down to 40 too. i have a better idea on where it should be now

[Superdave]

I'd say 140 should work.. then see where that takes the BLM's.

[Alxsmt]

ok i will set it at 140

[Alxsmt]

also, how do i tell if my injectors are maxed out?

im going to go play around with the fuel on my stock injectors to get a feel for it

[Superdave]

It's a calculation.. I usually add it into excel when i'm viewing datalogs.

Injector duty cycle = PULSEWIDTH / ((60 /RPM ) * 1000) * 100

you don't want to go over 80%

[Alxsmt]

ok i dont get the last part of that lol

1988GTU pointed me to www.GMtuners.com and i may send them an email if i cant get this figured out on sunday. my data logger keeps freezing up my computer and its really pissing me off. if nothing else i can use there tune as a baseline for a local shop

[Superdave]

so what is your exact combo in the car right now that you are tuning?

[Alxsmt]

what do you mean?

[Superdave]

engine wise.. stock 3400?