The XJ's electric fuel pump lives inside the tank. When it dies you get a no-start; when it's dying you get hot-restart problems and stalling under load. Confirm with a fuel pressure test, then drop the tank to replace it. Plan a Saturday — a quarter of that is fighting rusted tank straps.
A failing fuel pump is one of the most common reasons an XJ won't start. The pump is fully submerged in the tank — fuel cools and lubricates the motor, which is why running the tank to empty repeatedly is the single fastest way to kill one. By the time the pump can't build pressure, it's usually been showing symptoms for weeks: a stumble when accelerating from a stop, a longer-than-normal crank after the engine has heat-soaked, or a momentary loss of power on a hot day when the in-tank pump can't keep up with demand.
Three things make this job year-specific. First, the fuel pressure target changes by era — 31 psi on Renix (1987-1990), 39 psi on early HO (1991-1995), and 49 psi on the returnless 1997-2001 system. Second, the part itself changes — the Renix and early HO use a pump-only assembly with a separate sender, while 1997-2001 trucks use an integrated module that combines pump, filter sock, pressure regulator, and fuel level sender into one unit you swap whole. Third, 1996 is a transitional year that splits the difference and uses a one-year-only setup; double-check the part number before ordering. The procedure to drop the tank is essentially identical across all years.
Before you do any of this, test fuel pressure first. A fuel pump module costs $100-$250 and the labor is a half-day. A bad coil, a failed crank position sensor, a clogged sock filter inside the tank, or a failed fuel pressure regulator can all mimic a dead pump. The pressure test takes ten minutes and tells you exactly what's wrong.
Steps
Park on a flat, hard surface in a well-ventilated area away from sparks, open flames, water heaters, and grinders. Set the parking brake. Have a Class B fire extinguisher within arm's reach. This is the most flammable job you can do on the XJ — every step assumes you respect that.
Test fuel pressure before you commit. With the key off, connect a 0-60 psi fuel pressure gauge to the Schrader valve on the fuel rail (1991-2001) or to the test port on the supply line (1987-1990 Renix has no Schrader — tee a gauge into the supply line). Cycle the key to ON without cranking. You should see the pump run for two seconds, then shut off. Target pressure: 31 ± 5 psi (Renix), 39 ± 5 psi (1991-1995 HO), 49 ± 5 psi (1997-2001). Pressure should hold for several minutes after the pump shuts off — a fast bleed-down points to a leaking injector, regulator, or the pump's internal check valve. If pressure is low and rises with a clamped return line, the regulator is the problem, not the pump.
Run the fuel tank down to about a quarter or less before starting. Removing 18 gallons is miserable; removing 4 is manageable. The XJ tank vent is restrictive, so siphoning is slow either way.
Disconnect the negative battery cable at the post (10mm). Tuck it aside so it can't fall back. This kills power to the pump and prevents a stray spark while you have fuel lines open.
Relieve fuel system pressure. On 1991-2001 trucks, place a shop towel over the Schrader valve on the fuel rail and depress the valve core with a small screwdriver. Catch the spurt with the towel. On Renix, pull the fuel pump relay (in the PDC under the hood) and crank the engine for five seconds — it will start and die as the rail pressure bleeds off.
Get the truck up on jack stands at the rear, both sides, on the frame rail. The tank sits behind the rear axle on the driver's side and you need real working room under it. Wheels chocked at the front.
Siphon the remaining fuel out of the tank into a clean, sealable 5-gallon can. Use a hand-pump siphon — the EVAP rollover valve in the filler neck blocks gravity siphoning. Plan for 30-45 minutes. Pour back into the truck after the new pump is in.
Disconnect the filler neck from the tank. Two hose clamps (7mm or 8mm flathead) — one large clamp on the main fill hose, one smaller clamp on the vent hose. Twist the hoses to break them free. Have a rag ready in case any fuel runs out.
From under the truck, disconnect the wiring harness from the top of the tank. On 1987-1995 trucks this is two or three weatherpack connectors. On 1997-2001 it's a single multi-pin connector on top of the module. Squeeze the locking tab and pull straight off.
Disconnect the fuel lines. 1997-2001: two plastic quick-disconnect fittings (3/8 in. supply, 5/16 in. EVAP — there is no return line on this system). Use a horseshoe-style quick-disconnect tool, push the collar in, and pull the line straight off. 1991-1996: spring-lock or quick-disconnect fittings for supply and return. 1987-1990 Renix: rubber lines on barbed fittings — pinch the spring clamp with pliers, slide it back, and twist the hose off. Cap or plug each open line so debris doesn't get in.
Support the tank with a transmission jack or a floor jack with a wide piece of plywood across the saddle. The tank only weighs 25 pounds empty but it's awkward — get it level before you start unbolting straps.
Remove the skid plate if one is fitted (four 15mm bolts to the frame crossmembers). If the truck has no skid plate, skip this.
Unbolt the two tank straps. Each strap has one fixed end (hooked into a slot at the frame) and one bolted end (15mm through-bolt at the rear). Expect these to be seized. Hit each bolt with PB Blaster the night before. If a bolt snaps — and on a 25-year-old truck it usually does — drill it out and run a tap, or pick up a fresh strap kit (Crown 52000513) while you're at it. Don't try to muscle through with vise-grips on a half-rounded head while the tank is hanging.
Lower the tank in stages. Drop it a few inches, double-check that no lines or harnesses are still attached, then continue. On 1987-1995 trucks the EVAP vent valve and rollover valve are on top of the tank — confirm those hoses are free before the tank comes all the way down. Slide the tank out from under the truck.
Wipe the top of the tank clean. Dirt that falls into the tank during disassembly will be in suspension forever — it ruins new pumps. A pass with a vacuum on the top deck is worth the five minutes.
1997-2001 module: rotate the steel lock ring counter-clockwise to release the module. Use a proper spanner (Lisle 64900 or equivalent) or carefully tap it around with a brass drift and hammer — never a steel chisel that could spark. Lift the module straight up, tilting only as much as you need to clear the float arm and sock. Catch any remaining fuel under the module.
1987-1996 pump: the pump and sender are separate. Mark the orientation of the sender flange before removing screws, then pull the pump and bracket up through the sender opening or through its own access. The pump clips into a rubber isolator at the bottom of the tank and connects to the tank-internal hose with a hose clamp. Note the orientation and clamp position so the new pump goes in the same way.
Compare old to new before you install. Confirm float arm angle (sender resistance changes with float angle — getting it 90° off gives you a fuel gauge that reads backward), connector orientation, and the pickup sock isn't squashed. If the new module has a removable filter sock, make sure it's seated.
Install the new pump. 1997-2001: seat the new module with a fresh O-ring gasket lightly lubricated with clean motor oil (not fuel-rated grease — petroleum jelly is fine, silicone is not). Lock the ring clockwise until it bottoms against the tank stops. 1987-1996: install the pump into the rubber isolator, reconnect the internal hose with a new clamp, and reinstall the sender with a new gasket.
Pour the siphoned fuel back into the tank through the filler neck once everything is back in place. Doing this before reinstalling the tank gives you a leak check while the tank is still on the ground — drop a sheet of cardboard underneath and watch for wet spots for five minutes.
Hoist the tank back up with the jack. Get the filler neck nipples lined up with the body before you raise it the last few inches — these always need fiddling. Run the tank up snug against the body, then start the strap bolts by hand. Tighten the strap bolts to 30 ft-lb (40 N·m).
Reconnect the filler hose and vent hose with their clamps. Both clamps should be snug enough that you can't twist the hose by hand. Reconnect the wiring harness — listen for the click. Reconnect the fuel lines — push the quick-disconnects on until they click, then tug to confirm they're locked.
Reinstall the skid plate if applicable. Torque skid bolts to 22 ft-lb.
Reconnect the negative battery cable. Torque the terminal nut to 80 in-lb.
Prime the pump before cranking. Cycle the key to ON for two seconds, then OFF, three times in a row. Each cycle runs the pump and builds pressure. On the third cycle, leave the key on and confirm fuel pressure with a gauge if you still have it connected. Pressure should read in the target range for that year.
Start the engine. Expect a longer-than-normal first crank as the lines fill. Once it lights off, let it idle for two minutes and walk around the truck looking for leaks at the filler hose, the top-of-tank module, and the supply line fittings.
Drive the truck. Highway speeds, hard acceleration, and a hot restart after a 15-minute soak are the three real-world tests. If it pulls cleanly, restarts hot without cranking, and holds fuel pressure under load, the job is done. If it stumbles or pressure drops under demand, you either got a bad pump out of the box (it happens with Airtex and generic brands) or there's a second problem you missed in diagnosis.
Why it works
Fixes hard starts, no-starts, and hot-restart problems where the pump is genuinely the cause.
A modern Bosch or Carter module on a 1997-2001 truck restores OE-spec pressure and tends to outlast the original — early modules failed at 80-120k miles, and the current OE-equivalent Bosch unit (67410) is the most-recommended replacement on Cherokee Forum and NAXJA.
This is also the moment to fix every adjacent thing the tank drop blocks access to: rusted tank straps (Crown 52000513), a corroded fuel filler neck, rotten EVAP hoses, or a worn rear-of-tank skid plate. Doing them now is free labor — you have the tank out anyway. Skipping them means you're back here in a year.
An in-tank pressure gauge reading confirms the fix end-to-end. If pressure is in spec at the rail after the install, you know the pump, the filter sock, and the regulator are all working — which is more than a starts-and-runs test tells you.
Trade-offs
The tank is messy and heavy enough to be awkward overhead. Even at a quarter-full it's 30-35 pounds of liquid sloshing around — drop it on a jack, not your face.
The strap bolts are nearly always seized on a 20+ year old truck. Plan for snapped bolts and have a tap and a fresh strap kit ready before you start. Trying to wing it costs you the weekend.
Brand matters more than price. Bosch (67410) and Carter (P75040M) are the safe choices for 1997-2001. Airtex modules have a reputation for premature failure on XJ forums, and generic "BlackHorse" or no-name units off Amazon routinely fail within months. Spend the extra $60 — you don't want to drop this tank twice.
If the pump was the wrong diagnosis, you've wasted a day. The pressure test in step 2 is what tells you whether the pump is actually bad. Skipping it is the single most common reason DIYers replace a pump and still don't have a running truck.
The 1996 transitional system is a parts-lookup hazard. The tank, pump, and regulator are unique to that one year and not interchangeable with 1995 or 1997 hardware. Always order by VIN, not by "1994-2001 Cherokee."
Tools required
floor jack
jack stands
transmission jack or second floor jack
10mm socket and ratchet
13mm socket
15mm socket
fuel pressure test gauge (0-60 psi)
manual siphon pump
fuel line quick-disconnect tool (3/8 in. and 5/16 in.)
Written and maintained by an AZ wheeler and driveway wrencher. Always cross-reference your factory service manual — modifications affect vehicle safety and warranty. Work at your own risk.