Ok, I've looked at so many posts on the topic and have researched what appears to be a very common PITA. That said, I thought I'd tap the plethora of knowledge that exists with the users of this site as I’m scratching my head and losing hair by the handful. Here's my dilemma.

I just purchased a 1999 Disco 1 with a boat load of miles (~185,000). It ran great during the test drive (don't they all)!?! It had been sitting a while before I bought it, so I decided to burn a bunch of $4.00 gas through it to be sure it wasn't going to leave me stranded. During the first ~250 miles +/- it stalled out a few times while traveling at different speeds. It spit out an Evap Code, but that was it. I figured it was just some bad gas as the fuel filter was brand new.

Most of the time it would keep running, although it appeared to be very close to stalling out. One time it did stall entirely and needed to sit a spell before it would start. It turned over just fine and would even try to sputter a time or two. It just acted like it was out of gas. When it started, it ran another 50 miles just fine (proving it was not out of gas). Then I parked it and shut it off (note - it was running just fine when I shut it off). When I returned to restart it 3 hours later I was SOL. It wouldn't start - again, sounded like it was out of gas. So, this time I added additional gas (gauge now at 1/2 tank). No luck, it wouldn't start in spite of my commentary from the driver’s perch and ignition switch (trust me, it was colorful).

So, I towed it home to my tools and began to unravel the mystery. I started with the fuel pump - it would not cycle on when the key was turned to the "on". I checked for voltage across the 12V+ and ground wires at the pump and got nothing. I verified the pump was fine using a 12V source at the pump – it purred like a cat.

Next, I confirmed the 12V+ wire that comes from the Multifunction Relay in the engine compartment was fine using a continuity tester. I also verified the ground to the pump was fine in similar fashion.

I also verified I had no fuel pressure at the fuel rail, so clearly, my dilemma is the fact that the pump isn't running and the fuel rail has no fuel pressure to deliver gas to the injectors.

I jumped (by-passed) the Inertia Switch and tried to cycle the pump again (turning the key to “On”) - no dice!!

At this point I am scratching my head and am looking at the Multifunction Relay and the Crankshaft Position Sensor as they appear to be two likely culprits.

This brings me to my questions:

(1) Will the Crankshaft Position Sensor prevent the fuel pump from starting when the key is on and the fuel rail pressure is 0? If so, how does it do this? It would seem to me the sensor tells the ECM what rate the crank is turning; however, I would think the pump would start when the key is advanced even before the engine is cranked over if the fuel pressure is low (or non-existent as is the case with my Disco). Clearly, mine is not!

(2) Can somebody tell me where I can get the skinny on the Multifunction Relay (schematic, what all does it do, etc.)? I believe the Multifunction Relay will prevent the pump from running, but what else will it do.

(3) What am I overlooking? Oh yeah, did I mention I checked all the fuses and they are good. The battery is good! My Blood Pressure is bad and getting worse!!!

I greatly appreciate any assistance offered. I'm guessing this isn't the first time this dilemma has appeared with the Disco 1. I’m hoping someone can enlighten me (and many others who are similarly afflicted with Disco drama). I have to believe someone has ridden this Bull for the full 8 seconds!!! As for me, this is my first Disco Rodeo!

 

The electrical troubleshooting guide of the RAVE has pictures of the locations, looks like the side "footwell", I found it in section Z5 on page 43. But look at ETL section A1 page 4, which shows the fuel pump connected to the inertia switch and then to the immobilize and alarm circuits.... and what about K119, the fuel pump relay, on Section A1 page 3? Or am I on the wrong engine?

 

SB - Thanks for the reference citations. I've narrowed it down to the same items you've mentioned from the RAVE. I avoided any mention of that 4 letter word "Spider" because I really don't want to have to tear into the dash (and my security/immobilize system seems to be working fine). Which brings me back to the reason for my original questions - I'm attempting to figure out what triggers the pump when the key is on and fuel rail pressure is zero (you know, A to B causes C and so on).

 

Awful long thread for such a common Rover issue. Buy a new crank sensor and get your truck back on the road.

 

I have had the same problem on 2002 D2. Intermittent starting, stalled on I-95 once. Would crank but not start. Had P0560 code. Truck eventually would not start at all. Replaced CKS and CPS, no difference. Fuel pump would not run. Disconnected fuel pump connector and applied separate 12V and ground directly to fuel pump and it operated. Had power to fuel pump with key in P2 but would not start. Traced down to no ground on fuel pump relay coil, Pin #86. The ground for the fuel relay solenoid comes from the ECM pin #C0658-5. Shorted relay pin #86 to ground and truck started and ran. I think it would be okay to leave it this way as a permanent fix since I think the ECU only senses the conditions to provide the fuel delivery system a closed circuit. The fuel pump would still operate and shut off normally with the ignition switch position. I would like to find the definitive malfunction though. Any suggestions?

 

Still don't see how a crank sensor would keep the fuel rail from getting it's initial startup pressure....We're back to the immobilizer again...
The immobilizer is what keeps the fuel pump from running when the key is first turned on.. The crank sensor doesn't come in to play until the engine is turning...

If you can put +12V on that purple/white wire and get the pump to run...Then the problem is that the relay is not being picked...

A bad spider would keep the fuel pump from running as it should..The spider/immobilizer is in the fuel pump relay circuit and a bad solder joint on the PCB will keep the pump from running..I think you've troubleshot your way to this reality...

I'm going after mine soon...

John