Cdeez

Got a 27 PSI marine spring to feed my SBC that I'd estimate is ~400 FWHP. I have that spring in there and I'm now wondering what the best approach is to dialing in the fuel.

I read a LOT of mixed information on whether or not a VAFPR is worthwhile on a TBI setup. Should I get a VAFPR to bring AFR closer to stoich at idle or can I tune around without it? Idling pretty rich right now at around 10 or 11 AFR with the 27 PSI spring in there. Injector flow rate is setup in the tune as 91.

If it can be tuned without using a VAFPR, can this be done entirely on the VE table or should I be looking elsewhere as well?

RBob

iTrader: (1)

One item that helps is to get the injector compensation values correct. The injectors won't open as quickly and will also open more slowly.

RBob.

Dominic Sorresso

Cdeez

Where might those parameters be hiding in 7427 $0E mask?

RBob's EBL looks sweet and I've always drooled over it. However I need a way to shift the 4L80 I tossed in this particular truck otherwise I'd have already pulled the trigger on it. Not to mention the fact that he's always super helpful even to someone who isn't yet a customer. Slightly off topic, but in a world where customer service seems to diminish every single day, RBob and Moates seem to be some of the best I have ever encountered.

Moates shorted me (by accident I'm sure) a few 27SF512s a few years back, I made another order and mentioned that and they threw in the ones they owed me PLUS a handful of additional ones, free of charge. And then in the very unlikely event that my Burn1 blew up, they sent me a Burn2, again, free of charge. Most people only give feedback when they feel upset about a transaction/interaction and don't bother when they are content. These two fellas/groups are exceptional and a great asset to the community.

Sorry so OT.

RBob

iTrader: (1)

The offset compensation table:

Then the injector multiplier table:

RBob.

Cdeez

Thanks RBob,

I ended up copying the values for those two tables from what I believe to be a late model aka 95 454 TBI which should have used the high pressure fuel system to start with. As Fast pointed out to me in a different thread, likely a better starting point since it used the high pressure fuel system, even though the 454 injectors were the 4.3 injectors.

Been adjusting the min air rate and after I bumped my flow rate up to 160 PPH it's holding a nice steady idle around 14 AFR and has no hesitation when opening the throttle quickly.

RBob, what are you using to look at the code like that when you post those little snippets?

RBob

iTrader: (1)

You're welcome.

Notepad. There is a bunch of truck hacs available, $0E being one of them.

RBob.

Fast355

iTrader: (2)

I used the $OD Hac on gearhead in DonF's thread regarding timing advance. These PCMs have ALOT of code in them and alot of things going on behind the scenes so to speak but those are nothing compared to the newer stuff. From what I remember the TBI ECMs are 4KB, the PCM 64KB, black box Vortec 256KB, 0411 is 512KB and the newer Blue/Green LS is 1024KB from there it snow ***** with the newer PCMs. One of the things I hate about tuning OBD2 stuff with commerically available software. Change one thing that unkowingly changes 3 others and you don't have access to because the code was never fully reversed.