Tuning 7747

[WEG1192 at aol.com]

Tuning my first 7747 based system. I put a GM 5.7L TBI and GM 7747 on a Jeep 
360. Would hardly run at first until BLMs had done some major corrections by 
adding a lot of fuel. I have probably added over 40% to all values of the MAP 
vs. RPM VE table. At this point, all VE values above 50 KPa and 1200 RPM are 
over 61 when they were initially down around 40. I read in Bruce's Prog 101 
that the VE adder and the VE table values can't add up to more than 100%, 
otherwise the VE will be clipped at 100. Does this mean that any VE values I 
program over 61 are clipped at 61? I guess I don't understand the VE adder 
table. I zeroed this table out to see if it was PE mode only and the engine 
stalled so I guess its full time. Do I need to lower the VE adder table and 
compensate in the main fuel table? All my BLMs are still in the 150-160 range 
at all cruise loads and I reset the BLMs to 128 before each tuning run. It 
makes sense that I would have to add a lot of fuel since this truck only gets 
12 MPG compared to a Chevy 5.7L which gets 20+ MPG, but should I have to add 
this much? One comforting thing is that I do have 750 to 850 mV O2 at WOT so 
I am getting enough fuel. Just don't know where its coming from.

Thanks, and I hope to write up my tuning experiences for all future newbies 
for the GMECM site. Maybe it will help and maybe it won't.

JW
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