B2B vs. batch fire on 4 cyl.?


New Member
May 27, 2001
Something that I've been wondering about for a while: I have a SpeedPro managing my four cylinder turbo Toyota. The wiring harness that Force EFI made for the SpeedPro has all four injector leads coming from the same bank (ABCD), essentially making my bank-to-bank system a batch fire system. Would I see any perfomance or drivability gains by switching two of the injectors to the second bank? I guess the companion question is, when you set the Fuel Calc parameter to 4 cylinders, does this have any effect on which injectors the ECU actually fires?

The firing order is 1-3-4-2, so if I were to switch wires, I assume I'd be switching cylinders 2 & 3?

Just curious...


Put 1 and 3 on one bank, and put 4 and 2 on the other bank. You'll need to move two of the injector wires on the ECU connector. S1, T1, W1, and X1 are all pins that are part of the second bank. It doesn't really matter if you put 1 and 3 on the other bank or if you put 4 and 2 on the other bank, but that's how it should be for textbook bank to bank operation. I'm not sure you'll notice a difference in how it runs from the "batch fire" setup to the bank to bank setup. I believe that the injector timing for the cylinders you have on the second bank will move by 180 degrees of crank rotation. However, I had a rough weekend and any intelligent thoughts I may have to offer have been compromised. Packard part number for the ECU pins is 12103881-L.

Originally posted by Craig Smith
Packard part number for the ECU pins is 12103881-L.


Thanks, Craig. I think I'll give this a try in a little while. I have too many other, pressing things to do at the moment, but it shouldn't be too much trouble to move a few wires around. Say, one more question for you: where can I get these Packard 12103881-L ECU pins? I did a search on Google on the part number and didn't come up with anything useful.

Thanks again for your help,

OK, I had a chance to look at the pin itself, and actually, I think my local NAPA stocks 'em. If I can't find them, though, I send you an email.

Thanks again for your help with this,