Changed to FMS 24# injectors, BLMs now all 108.
No AFPR, want to do it all in the PROM. I see two injector constants - double fire and single fire. One is exactly twice the other. Seems obvious I need to change both.

Does this approach seem right?

1. Calculate the new constant a few #/hr higher, say 26#
2. Divide 10158.8 by 26 to get the new prom value of 391 (was 441 for the stock GM 23# injectors)
3. Put this value in the Single Fire location using Winbin
4. Double it and put that value in the Double Fire Location
5. Observe change in BLM's using scanner, rinse and repeat

Is that about it? (The prom is stock '86 Y-body, code BUB)

 

I dont know. On all my bins, both injector constants are the same if you look at the calculated value, not the raw #. Granted I'm using later model stuff, but I'd think yours would be both the same. May be wrong tho, hopefully someone will know for sure and shed some light on it.

 

My understanding is that our ECM's use the double-fire number only, but I'd keep them both the same.

Your logic is correct (BLM's low therefore rich therefore tell computer you have bigger injectors) but I don't understand your 10158 "prom" number - my constants are in engineering units (#/hr.). Are you using the correct mask to edit?