Milano Verde Air Flow Meter/bad MPG

["mmonsons" <mmonsons@domain.elided>]

I have been trying to fix up an 87 Milano Verde (140K mi.) with limited
success at great cost.  I started with basic change of all fluids, plugs,
t-belt, waterpump, tensioner. I replaced the exhaust with a Stebro from the
exhaust manifold back, including a new cat and o2 sensor, plus changed a
cracked manifold. Worked on the ABS; new break lines, change fluid, filter
screen, all fuses and relays, and accumulator.  Swapped the out-of-balance
driveline for a good used one and new donuts, and replaced the shifter bolt.
Got a good used power steering pump, a good used A/C compressor, and new
idler bearing. I was ending up with a lot of oil in the 'v' and filling a qt
of oil every 500 mi, so I had the heads removed to replace the gaskets.
Valves and cams checked out ok, so everything just went back with new
gaskets and valve/cam seals. Pretty much all the mechanical are in good
working order.

One of remaining problems I have is mpg, 9 city/ 10 road. All the gas lines
have been checked/replaced, the pressure regulator at 32 to 40 psi., new
fuel filter, new o2 sensor checks OK.  The tail pipe emissions do not
indicate a rich mix, but the new cat may mask this?  I checked the
odometer/tripmeter, due to undersized tires it actually records more miles
than traveled.  The only suggestion is the air flow meter flap has been beat
up by previous backfires and wants to reset itself to a rich mode.  Does
that make sense or is common?

My real question is this: I seem to remember someone using a BMW air flow
meter (in conjunction with 164S cams?).  Can you fill me in on why BMW part,
better mapping? adjustable?  I would think the meter/ECU/throttle all would
need to be part of the same system. It seems I am going to replace the unit,
so I would appreciate all and any suggestions.

TIA

Mike Monson

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