[Shotimes] lost MPG due to fuel pump?

[Erik Balser]

I've changed the fuel filter on 7/5/00, the IAB on 7/12/00, and the air
filter was changed to a K&N panel filter on 7/13/99.  The air filter has
been since cleaned and oiled.  I notice on my car the rev's go up to about
1200 rpm until the car has been running a minute, this must be the ultra
rich starting mode and then it settles down to about 800rpm.  But my problem
is upon inital startup, sometimes at vary times the engine will be flooded
when i go to start it.  I have to press the gas to the floor to start the
car.  My question it seems is why is the car flooded after letting it sit.
Sometimes it's only been sitting 1/2 hour and it won't start.  Ran a
cylinder balance test, but I'm told that won't check for leaky fuel
injectors.  Can't think of any other reason that the engine would be
flooded... Thanks, and if this makes any difference the ACT sensor comes and
goes when I run testing on the car.  I know the ACT sensor is fine too, so
maybe something else is amiss.
'95 MTX
masho95
http://webpages.charter.net/masho95

----- Original Message -----
From: "Kevin & Cheryl Airth" <clubairth@cajunnet.com>
To: "Erik Balser" <masho95@charter.net>; <shotimes@autox.team.net>
Sent: Tuesday, January 14, 2003 1:08 PM
Subject: Re: [Shotimes] lost MPG due to fuel pump?


> Erik:
>  Seems to be a lot of confusion here!
>  When the car is started from a cold state the fuel injectors give a ultra
> rich fixed mixture of 2:1. For a warm start condition (115F and above) the
> fixed fuel mixture is 12:1. So you are much more likely to "flood" the
> engine from a dead cold start condition (Less than 115F engine
temperature).
> Ford considers -20F as cold-cold and 115F as warm-cold. Note: The EPA
> considers 68F as "cold".
>  This rich mixture is fine if the engine starts but if it does not, you
will
> soon be flooded. You can get too much fuel when the IAB is not opening
> enough or when you don't have good enough spark/ignition problems or other
> things. When you keep cranking the engine, the PCM will cut back the
> injectors after 20 seconds. I have not been able to find out if they are
> shut off or just reduced? The PCM assumes the engine is over-rich and
needs
> more air and less fuel.
>  Now if you hold the accelerator pedal down the system enters the
> "De-Choking" mode.The fuel injectors are cut off completely as the engine
> try's to dry out the plugs and cylinders of excess fuel.
>  The IAB is fully open during engine cranking and supplies 100% of the air
> to the engine but has to close somewhat quickly and dynamically to
regulate
> the idle speed after the engine has started. Note that cranking and
starting
> are two different conditions! So your IAB might open fine and allow the
> engine to start but if it is sticky even a little bit the car might stall
or
> run rough until it warms up some. I think this is why most SHO's have a
RPM
> run up at start. The IAB can't react quick enough to control the engine
> speed. Mine usually goes to 2500 RPM and then settles down to the proper
> speed.
>
> I don't think this would impact your mileage but am not sure. Have you
> changed the fuel and air filters?
> .
> .
>
>
>
>
> > Just curious as my ongoing problem continues...is it possible for a weak
> > fuel pump to reduce the MPG of the car by 50-60 mpg per tank?  Just
> thinking
> > about when I had problems starting the car.  It wouldn't start due to
the
> > fact it was either flooded or from lack of fuel.  Anyone know what
happens
> > to the SHO when you floor the gas pedal on startup.  Does it cut the
> excess
> > fuel from entering or does it add more fuel upon startup?? My next step
is
> > to find myself a fuel pressure gauge and take some readings.  Thanks
> >
> > '95 MTX
> > masho95