7747 tuning again

[WEG1192 at aol.com]

I re-checked my fuel pressure and I apparently misread the gauge. I only have 
15 PSIG and it dips about 1/2 a PSI when I blip the throttle. I tried to 
check it on the road with a long fuel line but the hood pinches off the line 
when I close it.

I did another run this afternoon and on a whim, I changed the BPW constant 
from 140 to 160. Well, now I have BLMs down around 108 to 120 with the exact 
same fuel tables as before. Integrator numbers hovered around 128 the whole 
time. I drove 47 miles with about 30 of those miles at 70 MPH, and the other 
17 at around 55 to 60. I got a whopping 15.1 MPG. I topped off the tank 
before and after the trip to get the gallons used. I also checked the MPG on 
a previous tuning run where I did some fairly heavy accelerating to check my 
WOT O2 volts and I got 10.5 MPG. I also had drained some of the fuel into a 
reserve tank when I checked the return line for back pressure to see if it 
was keeping my F/P high. I think this is pretty good for a 4x4 5000 lb. truck 
with full time FWD.

But now I have to ask, Should I back out my fuel tables to where I just hit 
the 255 maximums, i.e. reduce the VE in both tables so that I have the same 0 
to 255 numbers that I do now, but with greater resolution in the lower part 
of the tables. Since I pushed all the numbers way above 255 and was getting 
some major clipping, I think I could regain some fuel preciseness on the 
lower end by reducing all the numbers back down to where the clipping just 
starts to occur. Overall, I'm pleased with the results, just trying to make 
sense of where I am so I can duplicate results on other AMC 360 engines.

One last thing, I noticed a random skip at about 70 MPH coming back. When it 
started to skip, I noticed my scantool randomly reporting engine speeds 
around 5000 RPM. Is this possibly due to having the ECM mounted in the heat 
of the engine bay? Or rather am I getting some EMI from the GM ignition 
module mounted only inches from the ECM? I have noticed the skip before after 
the engine has been running for a while. The BLMs were right on the money and 
nothing else seemed out of the ordinary.
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