I am probably the first to say this on this forum: I am at whit's end trying to find out what is going on. But, I am not getting the fuel pump to work consistently, or at all.

That being said: 1998 50th Anniversary - 4.0L

Long story long:

PO had a blown head gasket and just kept on going with coolant being nearly non-existent. I replaced everything on the top half of the engine:
Camshaft
Timing chain;
Push Rods;
Rocker Arms;
Heads Rebuilt;
Timing Chain;
Oil Pump Rebuilt;
Crankshaft Position Sensor;
Camshaft Position Sensor;
Fuel Pressure;
Fuel Rail Temperature;
Fuel Pressure Relief;
Fulle Injectors;
Idle Air Control;
Mass Airflow;
Air Filter;
Radiator;
Coolant Hoses; and
Thermostat & gaskets.

Prior to this, I had to replace the fuel pump because PO had done this but bought the $50.00 eBay ones that do not fit properly. I did the fuel pump and fuel filter. They work.

Then, after getting everything back together, I was getting a short from the crankshaft position sensor because the wires were melted away. Got those covered and afterward was getting fuel & spark (finally). In fact, there are no issues with spark.

Fuel pump has been intermittent in the sense that it simply would not work, then once all of a sudden power up. Specifically, I was messing around while someone was at the cargo area and I plugged in the fuel pump relay while I was under the hood. Everything powered up. I figured that was the problem, so I bought a new fuel pump relay. But, after plugging the new one in, there is nothing: I do hear a very tiny clicking when I plug the smaller plug in and I have the key in position II. No clue where it is coming from but generally it sounds as if it is on the passenger side of the engine as if something wants to occur but, cannot.


At this point, nearly everything is brand new and I have even tested wiring at certain parts. The fuel pump is new, and we tested the amount of electricity flowing to the fuel pump, as well as the smaller of the two plug-ins at the fuel pump relay. The collision switch has been removed, cleaned and tested and it appears to be functioning properly (This is the only thing that is actually not brand new). There is a fuse box under the hood and I have replaced that fuse as well as cleaned the connections. There was nothing actually wrong with the fuse.

There is a relay in the passenger side that when I put the key in and turn, I hear the requisite clicking. I have a brand new one but have not as of yet replaced this simply because the fuel system has intermittently powered up and this was never a variable.

What am I potentially missing or, where should I focus next?

Despite having brand new relays everywhere, I am going to clean the connections once again. I will as best I can test each connection to see if electricity is flowing. What should I be finding for electrical flow at each junction?

Thanks all that could help. I cannot believe that a Land Rover would drive someone to whit's end.

 

I have attempted to plug in and unplug the small plug portion of the fuel pump relay. When I did this, I got a clicking sound. We did this many times and I had help from a friend trying to figure out where the sound originates.

The audible clicking sound is going from the front of the engine, in between the radiator and toward the driver's side. It is not the crankshaft position sensor. My guy that was listening for it said it sounded as if it was coming from near the power steering pump area. But, we are not able to localize it entirely. Not certain this is anything.

Getting sound from something when I plug in the small portion of the fuel pump relay tells me power is being sent. But, I still have no fuel pump being actuated and fuel going to the fuel rail.

I tested the flow of juice going to the fuze box under the hood and I am getting a few volts there - about 3 which with a 15 fuse that makes sense.

 

Did you check at the LR wheel fender area & verify the short fuel pump harness isn't corroded? You should have 12v when the key is first put into position II.

 

Here is a diagram of the circuit. Plenty of points to check for power.

You can download the entire manual from the google drive linked in my signature. look for etlj970x.pdf in the D1 section.

 

I just tested all of the ares for the flow of electricity going to each connection. There are two fuses and both have current flowing. I tested at the fuel pump, fuel pump relay (inside engine compartment), and the inertia switch. Voltage is flowing at all points.

What did not work was we set up a battery at the fuel pump itself and attached directly to the fuel pump trying to bypass everything. Keep in mind, we tested voltage at the fuel pump and there was flow of current. But, we could not get the battery to be hot wired directly to do anything, not even make a peep. The fuel pump is brand new but, it has operated for a small period and intermittently. What we do not know is if this could have worked to begin with... there are four plugs at the fuel pump motor switch and three plugs at the gas gauge switch. We only used two wires. The gas gauge does work, btw.

Is it actually possible to hot wire the fuel pump and get the motor operating?

*** Thank you Walt for the schematic. I looked in the many, many places that I had already downloaded from you perviously but could not actually find that one schematic.
*** Thank you Best4x4 for the input. The wiring looks to be in very good shape across the board as this is a dessert area that the rig has spent its life. corrosion is not something we worry about too much here. Nonetheless, I inspected and tested the wiring and am getting flow.

 

First, thank you to the two individuals that helped on this with their replies: greatly appreciated and it ultimately led the to discovery of the issue.

PO replaced the fuel pump with one of those cheap $50.00 fuel pumps off of eBay instead of the correct fuel pump. Ultimately, this would blow out because they were not the correct ones. When I replaced the fuel pump myself, after inspecting the plugs, I saw that there must have been some arching in the wiring. Everything was dirty and corroded. I cleaned up as much as I could. But, one thing I did not look to fix was the plug itself with the spacing.

In the picture below, you can see the top plug LH side is expanded. This is the ground wire for the fuel pump that if you are standing at the back is the plug at the bottom left. As you can see in the photo, the plug is expanded and was likely dirty inside. I took a paperclip and scratched as much surface inside as I could, then took a needle-nose plier and crimped the plug so that it would grab the pin inside the fuel pump as tightly as possible.

Plugged it in, voila. Pump powered right up.

It was the schematic that my guy was checking that WaltNYC sent over. My guy was looking at the schematic to determine which plug went to the ground and which was hot, and so on. He told me they were numbered. I took my camera out there and took photos. I had to expand the phot and that is when I saw what the plug actually looked like, as you can see in the photo attached.

Thanks again for the help. I try and pay it forward as much as I can with what I have already learned... which, at this point is having replaced nearly every single part on the rig.

 

Good news. It’s always great to hear what the solution was.

 

Yep thats the short fuel pump harness I was talking about! Glad you got it fixed. They usually get nasty by the LR tire due to water getting into the connector. In your case the plug wasn't properly seated on those 50.00 pumps so it arched over time causing that one pin to get messed up.

Glad ya found the issue!