I've got a high-mileage 1994 Discovery I. It sits most of the time, inside my commercial heated building. I needed to move it the other day, and it started right up, then died after just a few seconds. I tried cranking and cranking and it would crank over just fine, but absolutely no sign of wanting to start. I removed a spark plug wire and using a spare sparkplug grounded to engine, got a good spark every time that plug should spark. I checked the fuel pump fuse, and I (using my electronic skills) examined and tested the fuel pump relay, both the coil and the contacts are good. I also had my wife crank over and I tested the voltage to the fuel pump. Here is what I get there: When you turn ignition on, there is voltage for a second or 2, then no voltage, when you turn key over to crank, the voltage returns and is constant. Reconnecting the wire plug to the fuel pump there is no sound ever from the pump no matter whether ignition is on, or on and cranking. Of course I also checked the inertia switch and it was passing continuity, but it HAS to work for me to get any voltage back to the fuel pump anyway.

I'm fairly sure now that my fuel pump died. I see there are aftermarket vendors that sell them in the $`150 range, far below factory part cost. My main concern is getting the big plastic ring unscrewed without a special tool, maybe I am being over cautious, but would appreciate any advice. I just can't see how it could be anything else, other than the fuel pump, as the engine has spark, and I have 1/2 tank fuel, and there appears to be no activity from the fuel pump even though it appears to be getting power.

 

I think it's safe to assume you've lost a brush or two on the fuel pump by what you've described. A few taps with a 1x1x24" length of wood and light hammer would get the ring to start to turn without destroying anything. Couple of shots of PB Blaster around the ring and let soak would help it to glide a bit better. You'll probably need the gasket though so a call or order through Rovahfarm.com can get it to you quickly. I usually just change the pump motor, not the assembly, it's a waste throwing out a perfectly good cage and float. By the way the initial pump voltage only lasts a few seconds unless you start the motor, it's priming the line pressure. Your reading are correct, nothing wrong.

 

Before my 1995 disco finally died six months ago I also had a fuel delivery problem.

I removed the fuel pump, filled it with alcohol and connected a battery directly. There was some hesitation and then the pump woke up and squirted a two ft squirt. Maybe try that before you buy another one.

I have a failure to spark and ran the RAVE tests with my multi-meter between the battery and the coil. This is what I got below. Could you maybe spend 5 minutes and do the same and tell me what you got?

First ignition OFF, and then ignition ON for a second run:

1. Battery negative to coil positive. I get 0 volts (RAVE wants battery voltage minus some (not below 11).

2. Battery negative to coil negative. I get 0 volt (RAVE wants same as above).

3. Battery positive to coil negative. I get 12.3 volts (Rave wants 0 volts)

4. Battery positive to coil positive). I get 12.3 volts )Rave wants zero).

I do not understand why a reading of 12 volts should be measured from the battery negative to the coil LT terminals.

Your time is much appreciated, thank you.

 

Well, I don't have any ignition issues. I'm not keen on getting a failed fuel pump to "wake up" because while it may run for a while, it would be on borrowed time. No, I want reliability, so I have ordered the necessary parts to replace the pump.

 

Thanks so much for recommending a vendor in MY OWN STATE, horray! AND has very good prices. I ordered all I think I need from him.

 

Your welcome! Let us know how it goes. The ring is a bugger at first but a little patience goes a long way, it took many years for it to become that tight..... a few minutes extra is good practice. The fuel line connectors are more than likely corroded as well, again use whatever you have on hand and let soak in.

 

I was asking for a favour, please, because you do NOT have no ignition issues. It was for me to understand the readings I get. If your readings agree with the RAVE manual I know Rave is correct and I have to find the reason why mine reads opposite. If your readings are the same as mine I now RAVE is wrong.

 

I'm sorry, I did not do any diagnostic procedure on the ignition outside of determining I had spark, the old fashioned way, with a sparkplug on the end of a sparkplug wire, grounded to engine.

 

Allow me to step in and untangle this, make sense of what's being asked.

Montero is asking if you would confirm the tests in the Service Manual called the "Rave". He has an ignition amplifier problem that eats them in about 14 days and his truck will not fire the spark plugs until he replaces the amplifier with a new one each time, then it pukes again in two weeks. The tests are spelled out in the "Rave" and he has performed them with the readings he's posted. He's looking for confirmation of his readings vs. the Raves to see if one or the other are correct/incorrect. It's been a long drawn out problem for him.

Most of us have a crankshaft fired ignition system, not a distributor fired system and that is why he's asking you for help. 94/95 Disco's came with distributors, 96 - 99 1/2 are crankshaft fired spark - Crankshaft Position Sensor that reads triggers off the flywheel - electronic through the Engine Control Unit - computer. The computer on early Discos controls the fuel injection system only, the later computers control the whole enchilada, spark + fuel injection and are Sequentially controlled meaning each cylinder has it's own advance/retard of the spark timing.

The "Rave" can be downloaded here; land rover service factory manual RAVE download land rover resource, service manual, workshop factory manual, download, rave, vehicles including discovery, series, defender, range rover, freelander, LR3, Handbooks, Catalog, Catalogue, Land Rover Inte and is the 590mb file. Great to have by the way.

Since you performed an accurate check of your fuel pump he feels your able to help with the diagnostic of the ignition system as well. He is unsure of his electrical readings and has little experience. Make sense to you now? I would love to help him but I have a 97 and cannot confirm the tests or else I would have a long time ago......

 

I see, most people don't have the 94-95 distributor fired engine? Actually I don't have the RAVE, all I have is a Haynes manual. I have ordered the fuel pump and related bits and bobs to install, and while I did a backyard mechanic spark test, I'm not inclined to go thru a comprehensive spark system test until I get the fuel pump installed and verify all is working OK. Then I would feel confident that my readings would be correct.