91 Grand Wagoneer stalling in morning

My GW tends to stall unexpectedly w or w/o warning first thing in the
morning, until it is fully warmed up. I have replaced the ignition
module, with maybe a 75% improvement. It still stalls. This morning
after about 5 min of normal running it seemed to go quiet, the voltage
meter dropped, I stepped on the gas after pulling over and putting it
in neutral, the meter returned to 'normal' range and as soon as I
eased my foot off of the gas pedal, the engine quit. It would start
repeatedly but not STAY "started". After about two minutes and four or
five attempts it started and stayed running all the way to work...

It has 89k in relatively good shape, everything works, except gas
guage. Had a recent oil change at Jiffy Lube last week, which also
seemed to improve the stalling problem...

any suggestions?

That could easily be a bad connection on the main body ground. It is a
mesh cable that runs from the rear of the engine head up to the
firewall. It controls the power to the ignition module when the key is
in run.

The vehicle can still steal a ground, lots of times it's through the gas
pedal.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

mmiller wrote:
>
> My GW tends to stall unexpectedly w or w/o warning first thing in the
> morning, until it is fully warmed up. I have replaced the ignition
> module, with maybe a 75% improvement. It still stalls. This morning
> after about 5 min of normal running it seemed to go quiet, the voltage
> meter dropped, I stepped on the gas after pulling over and putting it
> in neutral, the meter returned to 'normal' range and as soon as I
> eased my foot off of the gas pedal, the engine quit. It would start
> repeatedly but not STAY "started". After about two minutes and four or
> five attempts it started and stayed running all the way to work...
>
> It has 89k in relatively good shape, everything works, except gas
> guage. Had a recent oil change at Jiffy Lube last week, which also
> seemed to improve the stalling problem...
>
> any suggestions?

That could easily be a bad connection on the main body ground. It is a
mesh cable that runs from the rear of the engine head up to the
firewall. It controls the power to the ignition module when the key is
in run.

The vehicle can still steal a ground, lots of times it's through the gas
pedal.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

mmiller wrote:
>
> My GW tends to stall unexpectedly w or w/o warning first thing in the
> morning, until it is fully warmed up. I have replaced the ignition
> module, with maybe a 75% improvement. It still stalls. This morning
> after about 5 min of normal running it seemed to go quiet, the voltage
> meter dropped, I stepped on the gas after pulling over and putting it
> in neutral, the meter returned to 'normal' range and as soon as I
> eased my foot off of the gas pedal, the engine quit. It would start
> repeatedly but not STAY "started". After about two minutes and four or
> five attempts it started and stayed running all the way to work...
>
> It has 89k in relatively good shape, everything works, except gas
> guage. Had a recent oil change at Jiffy Lube last week, which also
> seemed to improve the stalling problem...
>
> any suggestions?

May also be a bad connection on the Crank Position Sensor. A friend had
similar problems that was traced back to a very dirty CPS connector, once
cleaned the problems went away.

Snow...

"mmiller" > wrote in message
m...
> My GW tends to stall unexpectedly w or w/o warning first thing in the
> morning, until it is fully warmed up. I have replaced the ignition
> module, with maybe a 75% improvement. It still stalls. This morning
> after about 5 min of normal running it seemed to go quiet, the voltage
> meter dropped, I stepped on the gas after pulling over and putting it
> in neutral, the meter returned to 'normal' range and as soon as I
> eased my foot off of the gas pedal, the engine quit. It would start
> repeatedly but not STAY "started". After about two minutes and four or
> five attempts it started and stayed running all the way to work...
>
> It has 89k in relatively good shape, everything works, except gas
> guage. Had a recent oil change at Jiffy Lube last week, which also
> seemed to improve the stalling problem...
>
> any suggestions?

May also be a bad connection on the Crank Position Sensor. A friend had
similar problems that was traced back to a very dirty CPS connector, once
cleaned the problems went away.

Snow...

"mmiller" > wrote in message
m...
> My GW tends to stall unexpectedly w or w/o warning first thing in the
> morning, until it is fully warmed up. I have replaced the ignition
> module, with maybe a 75% improvement. It still stalls. This morning
> after about 5 min of normal running it seemed to go quiet, the voltage
> meter dropped, I stepped on the gas after pulling over and putting it
> in neutral, the meter returned to 'normal' range and as soon as I
> eased my foot off of the gas pedal, the engine quit. It would start
> repeatedly but not STAY "started". After about two minutes and four or
> five attempts it started and stayed running all the way to work...
>
> It has 89k in relatively good shape, everything works, except gas
> guage. Had a recent oil change at Jiffy Lube last week, which also
> seemed to improve the stalling problem...
>
> any suggestions?

have you checked the O2 sensor?

have you checked the O2 sensor?

Mike, would it be possible to run a wire in parallel w/the existing main body
ground (the mesh cable)? Would it be possible to provide an alternative ground?
What sort of wire/cable/gauge would you recommend for replacing or possibly
running in parallel w/the existing mesh ground?

>That could easily be a bad connection on the main body ground. It is a
>mesh cable that runs from the rear of the engine head up to the
>firewall. It controls the power to the ignition module when the key is
>in run.
>
>The vehicle can still steal a ground, lots of times it's through the gas
>pedal.
>
>Mike
>86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>88 Cherokee 235 BFG AT's
>


-Bill (remove "botizer" to reply via email)

Mike, would it be possible to run a wire in parallel w/the existing main body
ground (the mesh cable)? Would it be possible to provide an alternative ground?
What sort of wire/cable/gauge would you recommend for replacing or possibly
running in parallel w/the existing mesh ground?

>That could easily be a bad connection on the main body ground. It is a
>mesh cable that runs from the rear of the engine head up to the
>firewall. It controls the power to the ignition module when the key is
>in run.
>
>The vehicle can still steal a ground, lots of times it's through the gas
>pedal.
>
>Mike
>86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>88 Cherokee 235 BFG AT's
>


-Bill (remove "botizer" to reply via email)

For testing I use a battery booster cable, but otherwise I use a battery
cable from the negative post to the body. Basically the ground then
comes from the body to the battery and on to the engine block more or
less in one solid path. My Cherokee is wired that way right now. So is
my CJ7.

The engine to body one has to be open mesh for vibration resistance.
This corrodes way too fast for my liking so I usually get creative with
covered battery cables.

You have to make sure the ground is large enough to handle all the
current draw which is why I go with a battery cable. They sell them
with loops on both ends.

Mike

Wblane wrote:
>
> Mike, would it be possible to run a wire in parallel w/the existing main body
> ground (the mesh cable)? Would it be possible to provide an alternative ground?
> What sort of wire/cable/gauge would you recommend for replacing or possibly
> running in parallel w/the existing mesh ground?
>
> >That could easily be a bad connection on the main body ground. It is a
> >mesh cable that runs from the rear of the engine head up to the
> >firewall. It controls the power to the ignition module when the key is
> >in run.
> >
> >The vehicle can still steal a ground, lots of times it's through the gas
> >pedal.
> >
> >Mike
> >86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> >88 Cherokee 235 BFG AT's
> >
>
> -Bill (remove "botizer" to reply via email)