1996 4.0 XJ Poor Man's Prime
...
Been having to do the 'Poor Man's Prime on my 96 - 4.0., lately.
After a few Ignition On-Off''s, it starts right-up with smooth engine start.
Looking to replace with :
Quadratec -
is this my only choice for the 96 ?
Thanks
lalo
Been having to do the 'Poor Man's Prime on my 96 - 4.0., lately.
After a few Ignition On-Off''s, it starts right-up with smooth engine start.
Looking to replace with :
Quadratec -
Crown Automotive 5003869AA Fuel Module for 1996 Jeep
Is the Fuel Pump dependable on this one andis this my only choice for the 96 ?
Thanks
lalo
Member



Joined: Oct 2023
Posts: 206
Likes: 101
From: Tip of the mitt, Michigan
Year: 1996
Model: Cherokee (XJ)
Engine: 4.0
No experience with the Crown.
For my 96 I bought a cheap hanger assembly (came with cheap pump), only because the original hanger was a pile of rust just like the tank.
Then I bought a Bosch pump and swapped that into the cheap hanger. After reading on here it seems like Bosch pumps are the preferred brand. That’s also what my original was, that still worked at 180k.
For my 96 I bought a cheap hanger assembly (came with cheap pump), only because the original hanger was a pile of rust just like the tank.
Then I bought a Bosch pump and swapped that into the cheap hanger. After reading on here it seems like Bosch pumps are the preferred brand. That’s also what my original was, that still worked at 180k.
CF Veteran



Joined: Aug 2020
Posts: 2,153
Likes: 585
From: SoCal
Year: 1988
Model: Cherokee (XJ)
Engine: 4.0L
Is the pump itself bad or is there a problem with the rest of the module?
The pump can be changed out easily enough as tlc1976 said. However, the fuel sender is different from the other years, It has 2 tracks for the fuel level instead of one like the rest. This is due to transition from ODB1 to OBD2.
From the FSM:
The fuel gauge sending unit is attached to the side of the fuel pump module. The sending unit consists of a float, an arm, and two variable resistors (tracks). These two tracks are used to send two different electrical signals. One is used for fuel gauge operation and the other is for OBD I I emission requirements.
Track 1-— fuel gauge operation: As the fuel level increases, the float and arm move up. This decreases the sending unit resistance, causing the fuel gauge on the instrument panel to read full. As the fuel level decreases, the float and arm move down. This increases the sending unit resistance, causing the fuel gauge on the instrument panel to read empty.
Track 2—OBD I I emission requirements: A variable voltage signal is sent to the PCM to Indicate fuel level. The purpose of this feature Is to prevent a false setting of misfire and fuel system monitor trouble codes if the fuel level in the tank Is less than 15 percent of its' rated capacity.
The pump can be changed out easily enough as tlc1976 said. However, the fuel sender is different from the other years, It has 2 tracks for the fuel level instead of one like the rest. This is due to transition from ODB1 to OBD2.
From the FSM:
The fuel gauge sending unit is attached to the side of the fuel pump module. The sending unit consists of a float, an arm, and two variable resistors (tracks). These two tracks are used to send two different electrical signals. One is used for fuel gauge operation and the other is for OBD I I emission requirements.
Track 1-— fuel gauge operation: As the fuel level increases, the float and arm move up. This decreases the sending unit resistance, causing the fuel gauge on the instrument panel to read full. As the fuel level decreases, the float and arm move down. This increases the sending unit resistance, causing the fuel gauge on the instrument panel to read empty.
Track 2—OBD I I emission requirements: A variable voltage signal is sent to the PCM to Indicate fuel level. The purpose of this feature Is to prevent a false setting of misfire and fuel system monitor trouble codes if the fuel level in the tank Is less than 15 percent of its' rated capacity.
...
I had the Battery Load-Tested and it's okay.
When it starts, the engine does not run rough,
so I ruled out injector leaks.
My Fuel Gauge works fine.
My guess is the Fuel Pressure Regulator
inside the fuel tank???.
The Module and Fuel Pump appear to be okay.
Are there one or two FPR for the 96?
Is/Are FPR available for the 96?
lalo
I had the Battery Load-Tested and it's okay.
When it starts, the engine does not run rough,
so I ruled out injector leaks.
My Fuel Gauge works fine.
My guess is the Fuel Pressure Regulator
inside the fuel tank???.
The Module and Fuel Pump appear to be okay.
Are there one or two FPR for the 96?
Is/Are FPR available for the 96?
lalo
CF Veteran



Joined: Aug 2020
Posts: 2,153
Likes: 585
From: SoCal
Year: 1988
Model: Cherokee (XJ)
Engine: 4.0L
Someone with a '96 will chime in soon.
The part you posted shows only a single fuel line to the pump assembly. That indicates the regulator is part of the fuel pump assembly.
My '88 has two lines as the FPR is located on the end of the rail.
There is a test port on the rail so you should check the fuel pressure, You should see 49psi +/- 2psi with the engine running.
There is a fuel filter under the body near the pump so you may need to check/replace it.
The part you posted shows only a single fuel line to the pump assembly. That indicates the regulator is part of the fuel pump assembly.
My '88 has two lines as the FPR is located on the end of the rail.
There is a test port on the rail so you should check the fuel pressure, You should see 49psi +/- 2psi with the engine running.
There is a fuel filter under the body near the pump so you may need to check/replace it.
The Crown assembly gets ok writeups, Carter (I think) got the best, but expensive and don't know whether its available
I have been doing a writeup on the '96 assembly recently, if you check archives, its recent
In your case. the problem appears to be check valves exist which fail....but I do not know if the check valve/s is in the pump or regulator ??
If it is in the pump (which I suspect), one can order a Bosch Pump & kit, install that onto the assembly, and it would be fixed (OEM quality)
If the regulator is at fault, its a Crown unit (have not updated part number for that yet, but can be found via a link on my thread).
Each of these parts are about $60 each
The pump assembly can be R&R with the tank in place, but you SHOULD make a video of extraction, as it must be twisted and turned like a ballerina to get out
If you jack the frame and let the rear axle assembly droop down, that would give you more clearance
If it was me, I would order a new Bosch pump ( for PRE-97 XJ), fit that, and see if its fixed. Always good to have a spare fuel pump, even if it takes a while to prime, beats the crap out of a stranded vehicle walking home
Preferably your tank is only about 1/4 full when remove assembly.
Be extra careful when install big o-ring
I have been doing a writeup on the '96 assembly recently, if you check archives, its recent
In your case. the problem appears to be check valves exist which fail....but I do not know if the check valve/s is in the pump or regulator ??
If it is in the pump (which I suspect), one can order a Bosch Pump & kit, install that onto the assembly, and it would be fixed (OEM quality)
If the regulator is at fault, its a Crown unit (have not updated part number for that yet, but can be found via a link on my thread).
Each of these parts are about $60 each
The pump assembly can be R&R with the tank in place, but you SHOULD make a video of extraction, as it must be twisted and turned like a ballerina to get out
If you jack the frame and let the rear axle assembly droop down, that would give you more clearance
If it was me, I would order a new Bosch pump ( for PRE-97 XJ), fit that, and see if its fixed. Always good to have a spare fuel pump, even if it takes a while to prime, beats the crap out of a stranded vehicle walking home
Preferably your tank is only about 1/4 full when remove assembly.
Be extra careful when install big o-ring
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Senior Member

Joined: Jul 2011
Posts: 560
Likes: 26
From: West Covina, Ca.
Year: 1988
Model: Cherokee
Engine: 4.0
Note from DJ
Here is the writeup that awg was referring
https://www.cherokeeforum.com/f2/reb...1-96-a-270618/
Here is the writeup that awg was referring
https://www.cherokeeforum.com/f2/reb...1-96-a-270618/
Member



Joined: Oct 2023
Posts: 206
Likes: 101
From: Tip of the mitt, Michigan
Year: 1996
Model: Cherokee (XJ)
Engine: 4.0
I would just do it right and replace the pump. And the sender if it’s a rusted mess, otherwise just use the same sender.
Someone with a '96 will chime in soon.
The part you posted shows only a single fuel line to the pump assembly. That indicates the regulator is part of the fuel pump assembly.
My '88 has two lines as the FPR is located on the end of the rail.
There is a test port on the rail so you should check the fuel pressure, You should see 49psi +/- 2psi with the engine running.
There is a fuel filter under the body near the pump so you may need to check/replace it.
The part you posted shows only a single fuel line to the pump assembly. That indicates the regulator is part of the fuel pump assembly.
My '88 has two lines as the FPR is located on the end of the rail.
There is a test port on the rail so you should check the fuel pressure, You should see 49psi +/- 2psi with the engine running.
There is a fuel filter under the body near the pump so you may need to check/replace it.
My 91 4.0 - MJ has the Fuel Pressure Regulator and the Test Port on the Fuel Rail.
The 96 XJ Fuel Rail does not have the Fuel Pressure Regulator.
~
Are the Bosch Fuel Pump and the FPR the same for both of these years?
I have one of each, spares for the MJ.
I'm changing the Fuel Filter, to start.
lalo
Last edited by lalo; Nov 30, 2023 at 12:48 PM.
theres idiots everwhere.... my 96 has 310k miles on it. all original. even the ac has never been touched. i put a clutch in it a a water pump.uses zero oil runs like a champ. Take care of it and it will take car of you.
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