fuel pump changed and still not running
 

i changed out the fuel pump on my 98 cherokee thinking that was my
problem but still won't run

here's what happened---when i would try to start the jeep it wouldn't
start with the first turn of the ignition but ALWAYS started on the
second turn---one day i ran the fuel level really low (damn gas prices)
and the thing wouldn't start at all---i put about 4 gallons of gas into
the tank and still nothing--gauges were reading no gas in the tank even
though i know there were at least 4 gallons in there---ideas please

thank you in advance for any suggestions

Re: fuel pump changed and still not running
 

That sounds like the 'very' common bad connection on the CPS of the 4.0
engines. The Crankshaft Position Sensor's plug sits on top of the
exhaust manifold and is extremely sensitive to it's connection. They
are just computer signal pins and the hot cold cycle affects them.
Sometimes you can just unplug it and plug it back and the little scratch
pin will make a new contact, but the best is to use a spray contact
cleaner. WD40 will work in a pinch, but isn't the best. After cleaning
it, I recommend some dielectric grease on the plug's seal skirts to help
keep condensation out of it.

But then the gauges not reading strongly implies a failed ground strap.
The strap is an open mesh strap that runs from the rear of the engine
head up to the firewall. I would check it's connections and give it a
squeeze to see if the mesh crumbles. Up here in the salt belt, that
failure is more common than the CPS one and the engine will sometimes be
able to start by stealing a ground.

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

shell wrote:
>
> i changed out the fuel pump on my 98 cherokee thinking that was my
> problem but still won't run
>
> here's what happened---when i would try to start the jeep it wouldn't
> start with the first turn of the ignition but ALWAYS started on the
> second turn---one day i ran the fuel level really low (damn gas prices)
> and the thing wouldn't start at all---i put about 4 gallons of gas into
> the tank and still nothing--gauges were reading no gas in the tank even
> though i know there were at least 4 gallons in there---ideas please
>
> thank you in advance for any suggestions

Re: fuel pump changed and still not running
 

That sounds like the 'very' common bad connection on the CPS of the 4.0
engines. The Crankshaft Position Sensor's plug sits on top of the
exhaust manifold and is extremely sensitive to it's connection. They
are just computer signal pins and the hot cold cycle affects them.
Sometimes you can just unplug it and plug it back and the little scratch
pin will make a new contact, but the best is to use a spray contact
cleaner. WD40 will work in a pinch, but isn't the best. After cleaning
it, I recommend some dielectric grease on the plug's seal skirts to help
keep condensation out of it.

But then the gauges not reading strongly implies a failed ground strap.
The strap is an open mesh strap that runs from the rear of the engine
head up to the firewall. I would check it's connections and give it a
squeeze to see if the mesh crumbles. Up here in the salt belt, that
failure is more common than the CPS one and the engine will sometimes be
able to start by stealing a ground.

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

shell wrote:
>
> i changed out the fuel pump on my 98 cherokee thinking that was my
> problem but still won't run
>
> here's what happened---when i would try to start the jeep it wouldn't
> start with the first turn of the ignition but ALWAYS started on the
> second turn---one day i ran the fuel level really low (damn gas prices)
> and the thing wouldn't start at all---i put about 4 gallons of gas into
> the tank and still nothing--gauges were reading no gas in the tank even
> though i know there were at least 4 gallons in there---ideas please
>
> thank you in advance for any suggestions

Re: fuel pump changed and still not running
 

That sounds like the 'very' common bad connection on the CPS of the 4.0
engines. The Crankshaft Position Sensor's plug sits on top of the
exhaust manifold and is extremely sensitive to it's connection. They
are just computer signal pins and the hot cold cycle affects them.
Sometimes you can just unplug it and plug it back and the little scratch
pin will make a new contact, but the best is to use a spray contact
cleaner. WD40 will work in a pinch, but isn't the best. After cleaning
it, I recommend some dielectric grease on the plug's seal skirts to help
keep condensation out of it.

But then the gauges not reading strongly implies a failed ground strap.
The strap is an open mesh strap that runs from the rear of the engine
head up to the firewall. I would check it's connections and give it a
squeeze to see if the mesh crumbles. Up here in the salt belt, that
failure is more common than the CPS one and the engine will sometimes be
able to start by stealing a ground.

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

shell wrote:
>
> i changed out the fuel pump on my 98 cherokee thinking that was my
> problem but still won't run
>
> here's what happened---when i would try to start the jeep it wouldn't
> start with the first turn of the ignition but ALWAYS started on the
> second turn---one day i ran the fuel level really low (damn gas prices)
> and the thing wouldn't start at all---i put about 4 gallons of gas into
> the tank and still nothing--gauges were reading no gas in the tank even
> though i know there were at least 4 gallons in there---ideas please
>
> thank you in advance for any suggestions

Re: fuel pump changed and still not running
 

try cycling the key 4 to 5 times with out cranking it.



"shell" <shell026@webtv.net> wrote in message
news:9045-432C2B33-554@storefull-3135.bay.webtv.net...
>
> i changed out the fuel pump on my 98 cherokee thinking that was my
> problem but still won't run
>
> here's what happened---when i would try to start the jeep it wouldn't
> start with the first turn of the ignition but ALWAYS started on the
> second turn---one day i ran the fuel level really low (damn gas prices)
> and the thing wouldn't start at all---i put about 4 gallons of gas into
> the tank and still nothing--gauges were reading no gas in the tank even
> though i know there were at least 4 gallons in there---ideas please
>
> thank you in advance for any suggestions
>

Re: fuel pump changed and still not running
 

try cycling the key 4 to 5 times with out cranking it.



"shell" <shell026@webtv.net> wrote in message
news:9045-432C2B33-554@storefull-3135.bay.webtv.net...
>
> i changed out the fuel pump on my 98 cherokee thinking that was my
> problem but still won't run
>
> here's what happened---when i would try to start the jeep it wouldn't
> start with the first turn of the ignition but ALWAYS started on the
> second turn---one day i ran the fuel level really low (damn gas prices)
> and the thing wouldn't start at all---i put about 4 gallons of gas into
> the tank and still nothing--gauges were reading no gas in the tank even
> though i know there were at least 4 gallons in there---ideas please
>
> thank you in advance for any suggestions
>

Re: fuel pump changed and still not running
 

try cycling the key 4 to 5 times with out cranking it.



"shell" <shell026@webtv.net> wrote in message
news:9045-432C2B33-554@storefull-3135.bay.webtv.net...
>
> i changed out the fuel pump on my 98 cherokee thinking that was my
> problem but still won't run
>
> here's what happened---when i would try to start the jeep it wouldn't
> start with the first turn of the ignition but ALWAYS started on the
> second turn---one day i ran the fuel level really low (damn gas prices)
> and the thing wouldn't start at all---i put about 4 gallons of gas into
> the tank and still nothing--gauges were reading no gas in the tank even
> though i know there were at least 4 gallons in there---ideas please
>
> thank you in advance for any suggestions
>

Re: fuel pump changed and still not running
 

If It's out of gas, that was a big learning curve for me back in
'72 fuel injected VW.
God Bless America, Bill O|||||||O
mailto:-------------------- http://www.----------.com/

IsellJeeps wrote:
>
> try cycling the key 4 to 5 times with out cranking it.

Re: fuel pump changed and still not running
 

If It's out of gas, that was a big learning curve for me back in
'72 fuel injected VW.
God Bless America, Bill O|||||||O
mailto:-------------------- http://www.----------.com/

IsellJeeps wrote:
>
> try cycling the key 4 to 5 times with out cranking it.

Re: fuel pump changed and still not running
 

If It's out of gas, that was a big learning curve for me back in
'72 fuel injected VW.
God Bless America, Bill O|||||||O
mailto:-------------------- http://www.----------.com/

IsellJeeps wrote:
>
> try cycling the key 4 to 5 times with out cranking it.