Good day folks, new Discovery II owner here with problems. I am trying to save this Discovery from the crusher. I picked it up from the fellow that has given up and was going to junk it. It's a 99 Discovery II in decent physical condition visually with 154,000 on the clock.
It will not start.
It has no fuel pressure unless I pull the fuel pump relay and use a jumper wire to "jump" the voltage to the fuel pump...the pressure jumps to 52psi immediately when I do that.
Even after jumping the fuel pump relay, it will still not start...I have verified that the main relay engages and supplies power to the fuel pump relay.
I have verified that the ignition key supplies power to the ecm.
Does it sound like the ecm may be the problem?

 

Have you checked the inertia switch? That is designed to shut off the fuel pump in an accident. Make sure it isn't tripped.

 

Yes sorry I did verify the inertia switch is good and making connection. If I understand correctly when I turn the ignition key to position II the Ecm get that signal and engages the main relay which picks the fuel pump relay for four seconds unless the engine starts....well the fuel pump relay never picks so I never get fuel pressure but I can jumper the fuel pump relay contacts to run the fuel pump and still the engine will not start---the starter turns the engine but no spark so no start even with fuel pressure...my thinking is since the ecm won't pick the fuel pump relay it probably isn't doing other things as well. I started to pull the CKT sensor and check it but figured if the ecm wasn't getting past step one ...why go to step two.

 

ECM checks the CKP sensor to see if engine is turning (if so then keep fuel pump on) and to set spark timing. If no spark, suspect CKP (crank shaft position sensor). You could also be immobilized, what does the red LED on the dash do?

 

red light on dash does nothing unless I set the alarm and the fuel pump does not run unless I force it manually by bypassing the fuel pump relay.

 

Have you replaced the crank position sensor?
If it is bunk the fuel pump will not run.

 

No I have not replaced anything. I was under the impression that the fuel pump should run for four seconds even without turning the engine over...my fuel pump does not run....ever...unless I force it.

 

No signal from the crank sensor no spark or fuel pump.
Bad fuel pump relay no fuel pump.
You might have more than one problem.
Jump fuel pump relay, does engine run?
No?
Spark?
No?
Bad crank sensor.

Jump fuel pump relay, does engine start?
Yes?
Bad fuel pump relay.

 

If the ECM doesn't power the ignition module---no spark with or without a ckt sensor...since it never powers the fuel pump relay I'm skeptical it's powering anything else...Is there a sequence somewhere of what happens when---inside the ECM?

 

Maybe I need to introduce myself a bit so I don't come off sounding like a smart a?? ....a know-it-all....Anyway I am a retired computer tech and a hard core auto hobbyist...I have lots of computers and several cars...none of which are all original...So, I know the ECM is a computer and I know computers do things real fast but they only do one thing at a time. What I would like to know is, has anyone documented or found in the service manual the power up sequence for the ECM?......Thanks, Dan