[V8] ABH using lots of fuel!

[Tony and Lillie]

Dag,

I went through a long and gruesome process of troubleshooting on mine, which 
started at 27MPG on first ownership.
It ended up around 12mpg city, 15-16 highway. Well, I replaced the O2 
several times (4-wire) several tune-ups. Two or three coolant temp sensors, 
checked and double-checked timing. New caps and rotors. Good (ohm check) 
wires. Changed injectors. Checked spray pattern. Replaced FPR with new.

Only two codes ever. Constant O2 out of range (I think). Toward the end as 
it ran worse, I got an IAC valve out of range.

Anyhow, turned out to be the MAF. It was burned on one side, as if by a fire 
in the intake manifold. I can tell you how and why, but we won't get into 
that right now.

Anyhow, I believe there is a test procedure in the bentley for it. Might be 
worth a look.

Oh, and for the "too many miles it seems", they don't seem to care. Mine has 
330K miles on it.

Tony Hoffman

----- Original Message ----- 
From: "Dag Bøsterud"
Subject: Re: [V8] ABH using lots of fuel!


I changed the engine temperature sensor today. There's one in the back of
the right cylinder head that sends a signal to the ECU. There was no
difference whatsoever. The car runs just as rich. The spark plugs are black,
and the old oxygen sensor was all black, not the normal greyish-brownish
color you'd expect.

The engine runs smooth, but very rich... I really don't know what could
cause this.

/Dag
92 V8 4.2
...too many miles it seems...