[V8] MPG - now stalling

[d saad]

Now that I have had TWO ignition caps fail the same way - by slowly
degrading and arcing out to the plastic ground shield (both times to #1
cylinder), I would give the ignition system a good look. In my case,
performance slowly degraded and mileage went with it.

On the O2
sensor, is the engine and exhaust pipe well grounded? Some have gone with
the Ford 4-wire sensor to get around this problem. Since you seem to run
fine in open-loop mode, there has to be some input to the computer that is
whacked.

You have these inputs:
intake air temp
air
flow sensor
ignition sensors (three of them)
coolant temp
O2
road speed
brake pedal (I think anyway)

Not
monitored but important - fuel pressure and flow.

And the
automatic maybe has some inputs I would not know about.
Possible
dragging brake(s)
Alignment way out of whack - or tires way under
inflated - or wrong size for the speedo - causing you to think the MPG is
off - or the speedo itself may be reading wrong. I know mine is off a few
percent.

Dave

> Ok guys,
>    This is
what has happened so far. (some of it is a re-cap)
> 1. When I
bought the car, before I even had driven it I replaced the o2s
>
2. When I start driving the car I notice really bad gas milage (14mpg
> -used to 18.5mpg on my last v8 with more miles.
> 3. Check
codes, get 2341 - out of range - causes could be: leaks in
>
intake/exhaust, high or low fuel pressure, Ignition failure, bad o2s
> 4. Check o2s for output - seems to be functioning properly.
> 5. Car starts dieing intermittantly, expecially at a stop, then
stumbling
> horribly on the throttle - figure it is low ATF - find
out later it isn't.
> 6. Change X-pipe with another o2s in it due
to a patch job on the original
> x-pipe (thinking this is the
cause?), find that this o2s is bad and is
> putting out no signal
at all - this throws a code 2342 - disconnected o2s
> - car runs
great with no stalling but mpg stay around 13 or so.
> 7. Change
out old o2s with the new one I had bought - car immedieatly dies
>
at idle - throws the 2341 code again.
> 8. Where do I go from
here?
> 
> I really think that I need the time to pull
apart the intake to look for a
> vaccum leak, also I need to test
fuel pressure.  I have changed the FPR
> and MAF with known good
units.  If any one has any ideas let me know -
> expecially vaccum
leaks to look for - I can't afford the gas anymore, and
> besides
it bugs me to know that the car isn't right!
> 
>        
Thanks,
>              Jason
> 
> 
> 
> 
>
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