My car is running lean and my mechanic (good guy) has been unable to correct. He's as frustrated and stumped as i am.....

Here's the deal. 89 765, stock except for Dawes valve, A/F meter and Autometer calibrated boost gauge. I have checked the A/F meter, which tells me that the car is a lean machine, with a DVM as well, and it is spot on accurate. At full throttle, my O2 sensor reads no higher than about .860 to .870v.

The following have been checked as operating within spec or replaced, as noted:
(much of this has been done because it needed it anyway)

Replaced

O2 sensor
Knock Sensor
Temp Sensor
Main fuel pump
in tank pump and sending unit
check valve(main pump to fuel filter
Fuel Filter
Distributor
Plugs
Ignition wires
Hall sensor
Head (yes full head, warped due to heater valve failure)
TPS
Oil trap
MAF air hose
intercooler to throttle body hose
exhaust manifold gasket
intake manifold gasket

Swapped out with known good unit:

AMM
ECU


Bench cleaned:

injectors (all now running 55ml flow)
Intercooler
Throttle body

Tested as ok:

Cat converter (not plugged as suspected)
Fuel pressure regulator
fuel pressure itself
smoke test for vacuum leaks passed
compression on all cylinders good
engine timing

I burn only 94 octane gas

I am seriously willing to Paypal (or some other method of $ transfer) a reward to the first person who suggests the right solution for this. I'm patiently waiting to crank up my mbc to a respectable 12lbs!! Any suggestions i can pass on to my mechanic are welcome.

By the way, the car also is a dog from a standing start to about 2K rpm and about 4lbs of boost, then takes off, then tops out nicely, but LEAN, LEAN LEAN.

(when the warped head was swapped out, the old one was white and clean, very lean)

help and $$ to the winner!!

Peter