Disco 1 won't start

[bigmac]

Hi all need help, 94 300TDi disco will not start. It is an Elec problem can not get power to the Injector pump through the relay.
can start it by bypassing the relay and going straight to the injector pump but have to pull the wire off to stop it.
Have put in a new relay, checked all the fuses have power going to the relay but not coming out.

HELP PLEASE
thanks
Neville

[Quiggers]

This is curly but (your quote): checked all the fuses have power going to the relay but not coming out.

By your description the problem lies in the relay...


whats after the relay to stop transmission?

GQ

[ladas]

Hi all need help, 94 300TDi disco will not start. It is an Elec problem can not get power to the Injector pump through the relay.
can start it by bypassing the relay and going straight to the injector pump but have to pull the wire off to stop it.
Have put in a new relay, checked all the fuses have power going to the relay but not coming out.

HELP PLEASE
thanks
Neville

Have you checked the supply to the coil on the relay - as you know a relay is an electrical switch that uses a smaller signal wire to sitch a larger supply.

Normally four terminals are use, incoming from the signal to the coil, outgoing to earth - if a 'normal relay is used the terminal numbers would be

85 signal in
86 Earth

These could be the opposite way round,

Then you have the power (which is switched - by the signal)

Again on a normal relay the incoming power comes in on

Terminal 30 -

And goes to the pump on

Terminal 87.

I am not sure on a 300 tdi how things are hard wired - but generally you turn on the ignition - power is applied to terminal 85, this switches the terminals 30 and 87 - applying power to the pump.

Check the fuses, with the ignition on you should have 12v on terminal 85, 30 and 87

When the ignition is switched on - does the relay click

[bigmac]

The relay is a 70amp with six pins it can only be connected up the one way. there is 12v every where except on the wire going to the pump.
No cannot here it click.
Will take both relays to an auto elec tomorow and get them checked because the new one is a $140.
Thanks for the quick reply

[justinc]

This sounds suspiciously like an alarm spider fault...Does your disco have factory imobiliser, IE a key fob with 2 buttons?

JC

[justinc]

The relay is a 70amp with six pins it can only be connected up the one way. there is 12v every where except on the wire going to the pump.
No cannot here it click.
Will take both relays to an auto elec tomorow and get them checked because the new one is a $140.
Thanks for the quick reply


That 7 pin sucker is the glow timer relay.

They are silent in operation as they are a solid state timer unit

I say alarm spider fault.

will there be money on this?

JC

[bigmac]

No it dosen't have an imobiliser or any of that fancy stuff it is put the key in the door and turn.

[justinc]

Oh well, back to the beginning... HAve you checked the fuse with the 'lightning bolt' and engine illustration on it? 10 amp I think.(red) This is the one for the supply to the injector pump wire. Sorry I can't remember the fuse number or position, but it has that pic on it. It isn't in one of the satellite fuse arrays, it isn't far from the ABS one from memory, under the dash / steering column.
This is the same fuse that supplies coil + in the V8.

JC

[ladas]

The only info I have for a 300 tdi has a injector pump driven by the gears off the crankshaft. Must be an earlier model.

[justinc]

The only info I have for a 300 tdi has a injector pump driven by the gears off the crankshaft. Must be an earlier model.

Same actually, but this wire goes to a solenoid to supply diesel to the inlet of the pump, not allowing any fuel flow when off prevents pump actually injecting during cranking. Pump is still rotating but not pumping out any fuel.

JC

[Quiggers]

Toss the relay

GQ

[ladas]

Same actually, but this wire goes to a solenoid to supply diesel to the inlet of the pump, not allowing any fuel flow when off prevents pump actually injecting during cranking. Pump is still rotating but not pumping out any fuel.

JC

Thanks justin - I have looked at all the diagrams - I can't see a solenoid, or a relay for that matter - mind you it's late and I am tired

[justinc]

Thanks justin - I have looked at all the diagrams - I can't see a solenoid, or a relay for that matter - mind you it's late and I am tired

I'm off to sleep myself, I'll check on progress in the morning...

JC

[ladas]

Okay - fuel cut off solenoid, found the right diagram - but it hasn't got 7 wires from any relay - I think I had better look at it in the morning with fresh eyes.

[DEFENDERZOOK]

hey guys...dont discount the alarm spider that easily......

if the vehicle was bought second hand......its possible it didnt have the fob.....but it may still have the alarm.....?


or...it wouldnt start without it....?

[Graeme]

I had a problem with my RRC a few days ago where there was power to a relay but even pressing the relay contacts together didn't result in output from the relay. It turned-out to be a faulty fuse that must have had a high resistance connection that effectively went open-circuit when a decent load was placed on it. It registered 12v and even allowed enough current to operate the relay coil (as part of my testing), but not good enough to operate the driving lights.

[JohnE]

Fuel cutoff solenoid in the injector pump.
i don;'t think the 94;s had an alarm. if so it shouldn;t turn the motor at all, thats if it was the spider, well thats my understadning of spider faults.
how do you know there is no fuel going through did you crack one of the injector lines as it was cranking, ( a bit hard to do yourself, unless you have long arms, and three of them at least)
that would give you a definate no fuel problem.
Or perhaps, the sedmenter is clogged badly= no fuel
the fuel filter is shot+clogged sedimenter= no fuel
fuel pump kaput+fuel filter + sedimenter = no fuel

Not sure if the solenoid is powered up at switch of or powered down to close, i suspect powered up at start to open, check to see if there is any power to open.
If you havne;t cracked an injector line yet, i suggest you try that. then work back through the fuel system.


john

[Scouse]

hey guys...dont discount the alarm spider that easily......I think you can safely discount the alarm spider. It didn't feature into the equation until the 96MY (TA).

[bigmac]

Thanks guys just got home and read all the replys
it is not fuel as it will start by bypassing the relay
would it matter if I bypassed the relay and put a switch inside to turn it off when shutting down?
It does not have the alarm.

[ladas]

Thanks guys just got home and read all the replys
it is not fuel as it will start by bypassing the relay
would it matter if I bypassed the relay and put a switch inside to turn it off when shutting down?
It does not have the alarm.

This relay takes power to the fuel shut off solenoid then - is that correct.

I was a bit thrown when you said there was 7 wires to it, couldn't understand why you would have 7 - just to run a solenoid.

From the wiring diagrams I have here, there are just the four wires - sinal, earth, power in - power out. Must be the wrong diagram.

.................but in answer to your question, yes it would / will work - but if it was me I would need to know why it isn't working.

If you fit a switch - the switch and the cable/wire used must be rated for the power draw of the solenoid valve - and did you say the relay was 60 amps - that would be a pretty strong switch and big wire.

I'll have another look at the wiring diagram.

Don't suppose there is any chance of you posting a pic of the relay, and it's location is there

[bigmac]

The relay is on the back of the fuse box under the bonet it is a 70 amp relay.
I just tried new fuses and didn't make any diff

[ladas]

It appears that the solenoid is energised from the engine control load relay, - with 1 signal wire going to the ecm - 2 power to the ecm one to the fuel shut off solenoid, one to the ERG soleniod, one to the fuel qty solenoid.

So if all those others are working when you switch the ignition on, I cannot understand why the fuel sol valve isn't working - but does when you bypass it.

No breaks in the original wiring ?

[bigmac]

No breaks i even ran a new wire just in case.
can an auto elec test the relay if it is out of the car?

[ladas]

No breaks i even ran a new wire just in case.
can an auto elec test the relay if it is out of the car?

Yes, if you had a test meter you could do it

Are there any terminal numbers on the relay - as if you have a meter - and a bit of spare wire you can test it yourself.

Do you have a meter

[bigmac]

Yes i have a meter and wire there are no numbers on the pins
but I know the earth the power in and power out to the pump
I think I said that there are 7 pins it should be 6

[ladas]

Yes i have a meter and wire there are no numbers on the pins
but I know the earth the power in and power out to the pump
I think I said that there are 7 pins it should be 6

There should be a signal wire (12v) that activates the relay - you should be able to find which that one is from the meter

You say you know the earth.

Then there should be a permenant live from a fuse that when the relay is activated - it then supplies power to the solenoid valve on the pump.

So connect a spare wire to the signal tab. Connect another wire to your earth tab.

Connect the earth wire to the neg on the battery

Just touch the wire connected to the signal spade on the pos battery terminal - the relay - if it's working will click. Leave it connected, and using the meter test for continuity between the remaining terminals. Disconnect then retest those therminals

[bigmac]

Thanks for the help Ladas it seems like it might be an engine managment thing.
so I bypassed it with a switch until I can get time to take it to an auto sparky
It will get my son to work and back for a couple of days at least.

[ladas]

Thanks for the help Ladas it seems like it might be an engine managment thing.
so I bypassed it with a switch until I can get time to take it to an auto sparky
It will get my son to work and back for a couple of days at least.

Okay cock.

Hope everything goes okay

Ladas

[Bush65]

According to my workshop manual:

There is NO relay for the fuel shut-off solenoid. The power comes from the ignition switch.

The relay with 6 wires, is as JustinC said, the glow plug timer.

What may have lead you to believe this is the relay is, the wire to the solenoid connects to the white wire that runs from the ignition switch to the glow plug timer.

Also the manual does not show any fuses, just a fusible link in the supply to the switch and starter relay. If it had failed the starter motor would not run.