Hey guys, I am wanting to put together an economy tune for the obd1 6.5. I realize most of the older fellas who began this thread are nolonger active but I am in the hopes that some of you all might have some input on this. searching online reveals nothing for these engines and tuning details so I am going at this mostly blindly.
I wanted to start with the fuel table accelerator pedal vs rpm, seeing just how much the fuel (mm^3) can be reduced without going into a too lean of a condition and still be able to lessen fuel consumption overall. below is the stock fuel table shown in TunerPro for my 95 truck. is reducing these numbers by 5% too much across the board? I'm sure all you DB2 guys know when the fuel screw has been backed out too much. as for myself, I haven't really been around a diesel engine running too lean, so I don't know what to look for!
Looking at the table, the max mm^3 fuel is 66.25 at 100% throttle and 1800 rpm, reducing that by 5% would result 62.94mm^3.
the lowest fuel rate with the first increment of the throttle (6.25%) is 6.56mm^3, this reduced by 5% would be 6.23mm^3.
a question would be weather that decrease would gain any mpg's without turning it into a 3 legged dog in a race! if 5% isn't going to change much, what would normally be good percentage for an economy tune?
I am just beginning to learn more about tuning and took this one as a personal learning hobby, but my ultimate goal is to come up with two custom tunes, the economy one and one that's a slight step up from stock for performance. Later I might try to combine the two into a single tune to have the best of both worlds.