Still have a major rich running problem.  My original description of the 
problem is attached.  Since that posting, I have tested the Temp II sensor 
over its entire operating range and it falls nicely in the curve shown in 
Bentley.  Also went through all the other resistance checks shown in Bently 
(mostly at the ECU connector plug, which is where I also took my Temp II 
sensor resistance measurements).  Everything is right on the money. I have 
triple (at least) checked my connections and grounds.  I checked for any 
blockage on the fresh air intake.  No restrictions.  Revving the egine in 
neutral yields thick black smoke.  I observed that blipping the thottle 
quickly but to wide open throttle causes the AFM to snap fully open, of 
course, momentarily.  Anybody ever take notice of this?  

I have been told of other cases where all tests of the fuel injection system 
are positive and the problem being cured by replacement of the F/I wiring 
harness.  Has anyone ever heard of or experienced this?  VERY expensive thing 
to replace without being positive that its the culprit.

Will have the exhaust gas analyzed this week in hope that it will point to 
the problem.  Hopes for long-planned Memorial Day weekend vacation are slowly 
dieing.....

ORIGINAL MESSAGE

My '84 GL is running very rich. �Mileage is 10 mpg at best. �Blows thick 
black smoke when loaded (i.e. under acceleration). �Down on power in general. 
�Idle speed is eratic but does not stall (yet?). �Been driving her daily 
under these conditions for months.
Things I've done:
Checked/adjusted ignition timing. �Was retarded. �Now correct (at least 
close). �Made no difference.
Measured fuel pressure: �36 psi at idle with vacuum connected. �42 psi (at 
any engine speed) with vacuum line disconnected. �If increase engine speed 
(with vac. connected), fuel pressure decreases (yes, DECREASES) to about 32 
psi.
Swapped out the air flow meter for another (used but serviceable) one. �No 
significant change in behavior.
Examined the spark plugs. �All four were equally black and sooty.
I also cleaned (with electrical contact cleaner and, in case of ground 
connections, emery cloth) and exercised all of the connections I could find 
on the engine management wiring harness.
I plan to measure the Temp. II sensor resistance tomorrow.
An observation: �I noticed that the position of the AFM wiper is about 20 or 
25% "open" with the engine idling. �This seemed surprisingly high to me, but 
I have no reference. �Could be normal. �Anyone have any input? �I also 
adjusted the CO adjustment screw (under the plug on the AFM housing) and this 
had no real effect on the position of the AFM wiper. �Had a small effect on 
the quality of the idle.

I did a mechanical rebuild on this engine two years ago (did not do anything 
to the fuel injection/engine management system). �It ran fine and gave me 19+ 
mpg overall fuel mileage until this problem cropped up a couple months ago.

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