FireDemonSiC

Alright guys. Take is easy here as I am brand spanking new to tuning. About as fresh as you can get in the matter. I'm a tad bit lost as to what I've done wrong here and was looking for advice.

I just installed an EBL flash system into my vehicle. Just flashing a stock LB9 BIN without adjusting the BPC values for my specific combination, everything tended to run rich. Now, actually going back and reading through the plethora of directions and information, I calculated my BPC to be 156 based on the fact that I am running Bosch III 22# injectors at 50psi and have a .030" over 305 (310). Now the problem I am having is that everything is running too lean. Even with the WOT VE tables maxed out my AFR during WOT is anywhee from 13.5 - 14.5:1.

I don't see any tables or scalars that I can modify to add additional fuel during PE. I know that changing the BPC values back in the other direction will correct this problem, but then they wouldn't be right for my combination and I want to make sure I'm doing things the right way. What have I done wrong here?

RBob

iTrader: (1)

Increase the BPC values by 10% and continue tuning.

Did we ever run the injector compensation numbers for those injectors?

RBob.

FireDemonSiC

I did not check the compensation calibration because a google search for the Bosch III design injectors returned nothing.

It should be worth noting that the VE tables being maxed were AFTER already doing a mass increase of 15% throughout all the tables (The low speed table especially. I had to do this in order for the car to idle and drive. Otherwise, it would surge and stall out).

Orr89RocZ

iTrader: (20)

Yeah try just increasing bpc to allow enough range in ve table to cover everything

FireDemonSiC

OK guys thanks.

The BPC values is the tree I was barking up but wasn't sure if that was the proper way or if I had missed something.

I will change the numbers around and let you guys know how it works.

Dominic Sorresso

As RBob suggested, I would look to use the correct Inj. offset for those injectors. I'd also set the BPC where it should be and then determine whether u have enough injector or fuel flow.
If ur using EBL, you can see that the Inj. duty cycle is calc'd for you. If it's over 85%, may want to increase pressure or injector size. Altho that may affect idle.
Could be time to consider VAFPR if u have not already.

FireDemonSiC

Trust me when I say these injectors are more than adequate for my current setup. It's an RV cam 305 with stock 601 heads (For the next couple months at least before the 268XFI and 113s go in).

Before the EBL there was enough fuel and then some for the correct AFR with my 165 MAF setup. I'm also running a holley AFPR set at 50psi.

The fuel system itself is also capable. When I was setting up my nitrous jetting it was able to run rich enough to go 10:1 on a 150 shot (Luckily I didn't damage any ring lands!!!), so I know for sure it isn't a fuel delivery issue.

But something else I mentioned to Orr that I forgot to mention is that the BPC setting for the 3004 EBL BIN "out-of-box" had my WOT AFR damn near if not spot on. So I am thinking what I am going to do is start back with the original BPC setting and trim fuel from part throttle and choke where necessary. This should also give me plenty of headroom for the above mentioned mods.

Please share if you think this is not a good idea for whatever reason.

And also sorry for the noob question, but how do I calculate the injector compensation values?

Dominic Sorresso

The injector offset v BATT values are published in most cases by the manufacturer. RBob may have a database of them also.

FireDemonSiC

I was under the impression that the compensation values mentioned were the ones to account for the delay from the time it takes the injector to open. Or maybe both?

I do have a fuel pump hot wire kit I'm getting ready to install, if that makes any difference. I have an overdrive pulley on my alternator, so I tend to keep full voltage even at idle unless I have a lot of loads going which is not common.

Orr89RocZ

iTrader: (20)

Pump to hotwire is nice if you need the capacity. Typically single 255 is good to 500-550 whp na

Try base stock bpc and tune part throttle as necessary. Give motor what it wants. Wideband to confirm what narrow bands read at part throttle

Dominic Sorresso

Injector Offset is typically different for each injector, even from same manuf., depending on size of injector. Also, opening/closing times will change based on fuel pressure. Higher pressure, slower times. The offset will make the greatest difference in smaller injector PW.
Since its a "constant" at that voltage the smaller the calc'd PW, the offset constitutes a larger % of that PW. I just went thru this exercise w my LT-5 using ACCEL 21# injectors. Getting the offset correct makes a big diff. In driveability, idle quality, and even mileage.
However, it made little to no diff for WOT. Since I spend most of my driving time at part throttle cruise and idle, getting it right is important in enjoying my ride.

FireDemonSiC

I have the Bosch III 22# injectors, and doing a bit of searching it looks as if RBob has already done the research in the past:

https://www.thirdgen.org/forums/diy-...gn-iii-pw.html

Where he states in post #5 that these are 19# injectors is theoretically correct, as these are originally ford injectors which rates their fuel pressure IIRC at 38psi. That would put a 22# MPFI @ 43.5 psi to 19/lb at that pressure.

So from what I have gathered, just zero out the offset tables and fill in the battery compensation values according to what's in that post? Doesn't a change in fuel pressure need to be taken into account when computing the battery offsets (I am running 50psi)?

RBob, can you confirm this?

RBob

iTrader: (1)

The higher fuel pressure will change the injector dynamics some. What is the color and part number of the injectors you are using?

RBob.

FireDemonSiC

They are yellow. Give me a few hours to get to my car and I will get the numbers for you. I bought them a couple years from FIC.

Bosch design III 22# (19# rated).