LVDonkey

I'm having a problem with my 93 5.0.. it starts and runs fine, but
around 3/4 throttle or more it noses over and dies.. backfires until
you get off the gas. I just pulled the codes today.. I'm getting codes
18, 41, 91. I also ran the cylinder balance test and everything was
fine there.
My o2 sensors have about 6k miles on them so I'm going to go ahead
and assume they are operating ok. As for code 18, is that specifically
the spout connector or the TFI?? What do I need to replace on that
one?
As for 41, and 91 both indicate lean mixture and 91 a fuel pressure
problem. I disconnected the vacuum line from the FPR and took it for a
drive and it didn't change at all, so can I go ahead and assume that
the pressure regulator is the faulty component or could it still be
fuel pump/injector related even though it passed the cylinder balance
test?

Jim Warman

I think thet you're misunderstanding some of this stuff.... and then you're
goig to compound the error with assumptions.

DTC 18 can be set when a poorly maintained ignition system starts arcing and
sparking under the hood. Since this makes us real familiar with misfires, we
can deduce that these misfires are leaving a lot of oxygen free to go down
the pipe to be read by the sensors and PCM as a lean mixture (DTCs 41 and
91). In 1993, engine control systems weren't smart enough to know if they
were misfiring or not.

DTCs are a symptom and not a flat "replace component X" statement.

For your case, I would recommend a good basic ignition tune up including
cap, rotor and wires with close attention being paid to the condition of the
ignition coil.


"LVDonkey" <woods2073@cox.net> wrote in message
news:1135226809.065471.106160@g47g2000cwa.googlegroups.com...
> I'm having a problem with my 93 5.0.. it starts and runs fine, but
> around 3/4 throttle or more it noses over and dies.. backfires until
> you get off the gas. I just pulled the codes today.. I'm getting codes
> 18, 41, 91. I also ran the cylinder balance test and everything was
> fine there.
> My o2 sensors have about 6k miles on them so I'm going to go ahead
> and assume they are operating ok. As for code 18, is that specifically
> the spout connector or the TFI?? What do I need to replace on that
> one?
> As for 41, and 91 both indicate lean mixture and 91 a fuel pressure
> problem. I disconnected the vacuum line from the FPR and took it for a
> drive and it didn't change at all, so can I go ahead and assume that
> the pressure regulator is the faulty component or could it still be
> fuel pump/injector related even though it passed the cylinder balance
> test?
>

Robert A. Plourde Jr.

Could it be a dirty fuel filter?

"Jim Warman" <mechanic@telusplanet.net> wrote in message
news:y%sqf.995$AP5.568@edtnps84...
> I think thet you're misunderstanding some of this stuff.... and then
you're
> goig to compound the error with assumptions.
>
> DTC 18 can be set when a poorly maintained ignition system starts arcing
and
> sparking under the hood. Since this makes us real familiar with misfires,
we
> can deduce that these misfires are leaving a lot of oxygen free to go down
> the pipe to be read by the sensors and PCM as a lean mixture (DTCs 41 and
> 91). In 1993, engine control systems weren't smart enough to know if they
> were misfiring or not.
>
> DTCs are a symptom and not a flat "replace component X" statement.
>
> For your case, I would recommend a good basic ignition tune up including
> cap, rotor and wires with close attention being paid to the condition of
the
> ignition coil.
>
>
> "LVDonkey" <woods2073@cox.net> wrote in message
> news:1135226809.065471.106160@g47g2000cwa.googlegroups.com...
> > I'm having a problem with my 93 5.0.. it starts and runs fine, but
> > around 3/4 throttle or more it noses over and dies.. backfires until
> > you get off the gas. I just pulled the codes today.. I'm getting codes
> > 18, 41, 91. I also ran the cylinder balance test and everything was
> > fine there.
> > My o2 sensors have about 6k miles on them so I'm going to go ahead
> > and assume they are operating ok. As for code 18, is that specifically
> > the spout connector or the TFI?? What do I need to replace on that
> > one?
> > As for 41, and 91 both indicate lean mixture and 91 a fuel pressure
> > problem. I disconnected the vacuum line from the FPR and took it for a
> > drive and it didn't change at all, so can I go ahead and assume that
> > the pressure regulator is the faulty component or could it still be
> > fuel pump/injector related even though it passed the cylinder balance
> > test?
> >
>
>

LVDonkey

I initially thought it was the coil too, which I replaced a week ago,
the plugs and wires and cap and rotor were all replaced about 2 weeks
before that, the fuel filter has not however, I guess I will also try
that this weekend when I have some free time. The car has been sitting
for a while due to this problem and I just remembered now how this all
started, I had 2 plug wire looms break and 2 plug wires ended up on the
headers and burned through, which obviously caused misfiring however
when I replaced the wires it didn't go away which is when I replaced
basically the whole ignition system. Also this problem is much worse
at cold startup.. basically any throttle makes it want to die, I have
to wait till my A/F gauge starts bouncing around before pulling out of
my parking spot.

Ironrod

How was it running before you replace the all those parts?


"LVDonkey" <woods2073@cox.net> wrote in message
news:1135280541.068258.61000@o13g2000cwo.googlegroups.com...
> I initially thought it was the coil too, which I replaced a week ago,
> the plugs and wires and cap and rotor were all replaced about 2 weeks
> before that, the fuel filter has not however, I guess I will also try
> that this weekend when I have some free time. The car has been sitting
> for a while due to this problem and I just remembered now how this all
> started, I had 2 plug wire looms break and 2 plug wires ended up on the
> headers and burned through, which obviously caused misfiring however
> when I replaced the wires it didn't go away which is when I replaced
> basically the whole ignition system. Also this problem is much worse
> at cold startup.. basically any throttle makes it want to die, I have
> to wait till my A/F gauge starts bouncing around before pulling out of
> my parking spot.
>

LVDonkey

It ran great before the plug wire incident, after that happened is when
I started replacing the ignition parts.


Ironrod wrote:
> How was it running before you replace the all those parts?
>
>
> "LVDonkey" <woods2073@cox.net> wrote in message
> news:1135280541.068258.61000@o13g2000cwo.googlegroups.com...
> > I initially thought it was the coil too, which I replaced a week ago,
> > the plugs and wires and cap and rotor were all replaced about 2 weeks
> > before that, the fuel filter has not however, I guess I will also try
> > that this weekend when I have some free time. The car has been sitting
> > for a while due to this problem and I just remembered now how this all
> > started, I had 2 plug wire looms break and 2 plug wires ended up on the
> > headers and burned through, which obviously caused misfiring however
> > when I replaced the wires it didn't go away which is when I replaced
> > basically the whole ignition system. Also this problem is much worse
> > at cold startup.. basically any throttle makes it want to die, I have
> > to wait till my A/F gauge starts bouncing around before pulling out of
> > my parking spot.
> >

Ironrod

You're going to have to go into more detail about the plug wire incident.
If the car was running decent before you started replacing stuff, try
putting the old parts back on and see it the problems clear.

"LVDonkey" <woods2073@cox.net> wrote in message
news:1135331830.674061.179970@g44g2000cwa.googlegroups.com...
> It ran great before the plug wire incident, after that happened is when
> I started replacing the ignition parts.
>
>
> Ironrod wrote:
> > How was it running before you replace the all those parts?
> >
> >
> > "LVDonkey" <woods2073@cox.net> wrote in message
> > news:1135280541.068258.61000@o13g2000cwo.googlegroups.com...
> > > I initially thought it was the coil too, which I replaced a week ago,
> > > the plugs and wires and cap and rotor were all replaced about 2 weeks
> > > before that, the fuel filter has not however, I guess I will also try
> > > that this weekend when I have some free time. The car has been sitting
> > > for a while due to this problem and I just remembered now how this all
> > > started, I had 2 plug wire looms break and 2 plug wires ended up on
the
> > > headers and burned through, which obviously caused misfiring however
> > > when I replaced the wires it didn't go away which is when I replaced
> > > basically the whole ignition system. Also this problem is much worse
> > > at cold startup.. basically any throttle makes it want to die, I have
> > > to wait till my A/F gauge starts bouncing around before pulling out of
> > > my parking spot.
> > >
>

Jim Warman

Info in dribs and drabs is good..... The plug wire incident is when the
wires burned through on the headers? Are the wires assigned correctly for
the fring order?