Has Anyone replaced the fuel pump on nas110. Is this a job a novice should attempt? Is it super difficult without a lift? Once tank is down is there enough clearance to work or should the rear end be higher on jack stands? Does this require floor jack to lower the tank? Anyone care to talk about the misery involved?
Replacing fuel pump
- Thread starter phunter
- Start date
it’s pretty easy to do if your truck isn’t rusty. I would highly recommend getting an aftermarket cork gasket over the updated genuine parts gasket. The job is much more manageable without much fuel in the tank
I've replaced the fuel pump on my 1987 v8 gas 110. First I read the shop manual. Second I drained the gas. Mine had a drain bung. It helps to have a floor jack to help support the tank for lowering and raising the tank, especially if working alone. I did all the work on the ground, rear end not on jack stands or raised. No lift. Just be prepared for dirt and debris to fall onto you. In other words wear eye protection at the least. I'm a novice. I've since done more complicated tasks. I'd attempt it.
lordhelemt
Well-known member
I just dropped my tank 3x this spring due to bad fuel pumps. You’ll need to pull the rear bumper and drop the sway bar do you may want to soak those bolts in pb blaster a day or two before doing the job. There should be a drain bolt on the bottom of the tank but it makes a huge mess. I found it easier to siphon the gas out of the tank.
btw, you may want to test the pump before installing. First one I got was running backwards. Next one failed in 2 months.
btw, you may want to test the pump before installing. First one I got was running backwards. Next one failed in 2 months.
Be for I attempt this I thought I would make sure this is the next step. Obviously, I am not a mechanic.
I confirmed spark by putting plug on wire and resting on engine and attempting to start.
I confirmed no fuel on fuel rail by opening up fitting on fuel rail behind plenum near firewall. With this fitting open no squirt was seen with turning key on. The fuse was good and no squirt was seen swapping the 2 silver relays. I did not get new silver relays. I just swapped ecu relay to fuel pump spot with no squirt seen.
They fuel filter isn’t rusty at all but no pressure at all with fitting loose. I hear no hum with stethoscope on fuel tank.
next step is to drop tank and replace fuel pump??
I confirmed spark by putting plug on wire and resting on engine and attempting to start.
I confirmed no fuel on fuel rail by opening up fitting on fuel rail behind plenum near firewall. With this fitting open no squirt was seen with turning key on. The fuse was good and no squirt was seen swapping the 2 silver relays. I did not get new silver relays. I just swapped ecu relay to fuel pump spot with no squirt seen.
They fuel filter isn’t rusty at all but no pressure at all with fitting loose. I hear no hum with stethoscope on fuel tank.
next step is to drop tank and replace fuel pump??
lordhelemt
Well-known member
The pump is easy to hot wire without dropping the tank. Look by the rear drivers side wheel well. Look for the wire with the round connector that runs up to the top of the tank. Jump the connection directly to a battery. You'll should be able to hear the pump run. I don't remember which is hot/ground but it doesn't really matter (if you reverse them the pump will just run backwards).
Thanks for your help. The external battery jumped to the female part of the connector did make the pump run. It was quite easy to hear. I guess the next step is to use a test light to see if there is power to the male part of the plug with turning the key to position two??
if this shows no power then buy new silver relays or find someway of bench testing them?? Thanks for all the replies
if this shows no power then buy new silver relays or find someway of bench testing them?? Thanks for all the replies
lordhelemt
Well-known member
99% sure the problem is your ground. Pull the rear speaker housing (driver side) and check the grounds in the multi (shit) bullet connector. I found it easier to make all the ground connections to a blue sea grounding block and ran a ground wire directly to the battery.
Still in need of help. Finally able to find time today. I spent 20 minutes trying to get bolts out to remove jump seat to get panel holding rear speaker panel out The bolts spin loosely but won’t come all the way out. I could not get panel to slide out for it seems connected to the far brace holding the jump seat. I thought it was just the carpet holding it but seems connected to bolt with back brace.
Next I attempted to start defender using external battery charger as power source. The pump was quick to run but no start. I switched to both ways in female plug but no start.
Next I loosened fuel line on fitting at fuel filter with no squirt seen with use of battery charger to get fuel pump to run.
Does this mean I have a pump that will run since I hear it but won’t pump since no start or squirt at fitting before filter ?? so a bad pump?? Thanks for any and all replies. Obviously,
I am not a mechanic.
Next I attempted to start defender using external battery charger as power source. The pump was quick to run but no start. I switched to both ways in female plug but no start.
Next I loosened fuel line on fitting at fuel filter with no squirt seen with use of battery charger to get fuel pump to run.
Does this mean I have a pump that will run since I hear it but won’t pump since no start or squirt at fitting before filter ?? so a bad pump?? Thanks for any and all replies. Obviously,
I am not a mechanic.
lordhelemt
Well-known member
Try reversing the polarity when running the pump off the battery. If it’s wired backwards the pump will soon in reverse (suck not pump)
lordhelemt
Well-known member
If you can hear the pump run but nothing is coming out then the pump has some sort of failure or the is a blockage somewhere.
I’d just drop the tank and pull the pump and do an inspection.
A new pump isn’t too expensive
I’d just drop the tank and pull the pump and do an inspection.
A new pump isn’t too expensive
Got the fuel pump on and now have fuel pressure at the fittting behind the plenum but won’t start. Definitely hear fuel pump running.
Won’t run with starting fluid.
I do have a nice arc from wire going from coil to distributor cap. I don’t have any spark at the plug by pulling a plug and grounding it. I do not get a light by connecting a test light from plug wire to plug in the engine. I have installed new plugs, cap and rotor button.
Any tests I can do or words of wisdom.
Won’t run with starting fluid.
I do have a nice arc from wire going from coil to distributor cap. I don’t have any spark at the plug by pulling a plug and grounding it. I do not get a light by connecting a test light from plug wire to plug in the engine. I have installed new plugs, cap and rotor button.
Any tests I can do or words of wisdom.
easiest to check no spark is from Coil to Distributor - check for spark, then from one of the leads to the spark plugs.
IF spark ok at the coil, BUT No spark from the cap to the plugs = replace the rotor button.
IF No spark at coil = replace coil.
Check coil connections especally the Neg signal wire from the 14CUX to the coil - it will not run with out this hooked up. It is a white wire.
IF spark ok at the coil, BUT No spark from the cap to the plugs = replace the rotor button.
IF No spark at coil = replace coil.
Check coil connections especally the Neg signal wire from the 14CUX to the coil - it will not run with out this hooked up. It is a white wire.
lordhelemt
Well-known member
Since you have a spark from the coil to the cap it’s most likely the rotor or cap (probably the rotor).