Wont start after wiring

D90mitch · Mar 14, 2015

So, today I have been removing all the wiring from my discovery ready to cut the back off (becoming challenge truck). The vehicle has been sat for a while so the battery was a bit low however all electrical systems still seemed to be working.

I will make clear, I have just been disconnecting all the connections from the rear of the vehicle so I can bunch the wiring looms out of the way to cut the body. I have not touched any of the ECUs or front wiring. The vehicle started fine last time. When I first turned on the ignition, the fuel light was on and it was showing very low. I thought I had about quarter of a tank. After trying to start the vehicle a few times, no luck. Tried another battery and nothing. The fuel soon went to completely empty and the fuel light was off. The vehicle is turing over fine but won't fire. There is no noise from the fuel pump when turing on the ignition hence my reasoning to think I have disconnected something powering the fuel pump or along those lines. I just don't know where. I have labelled the looms as to where they went in the vehicle so I am confident that I know where they all go should I need to reconnect them.

What should I be locking for?

It's a '94 3.9 v8

Thanks.

D90mitch · Mar 14, 2015

Please

discool · Mar 14, 2015

Strange, assume u disconnect the battery before you interfered with the wiring, and therefore haven't popped a fuse.

Dippypud · Mar 14, 2015

Sounds like an earthing fault ...

jamesmartin · Mar 14, 2015

have you disconnected pump in the fuel tank

200tdi ayre · Mar 14, 2015

jamesmartin said:
have you disconnected pump in the fuel tank

+1

D90mitch · Mar 14, 2015

I haven't touched the fuel pump itself no. I can see the connector that goes onto the fuel pump in the tank next to the two fuel lines through the hatch in the boot floor. Seemingly though I must have disconnected something in-between?

200tdi ayre · Mar 14, 2015

check youve got power there is a good start

D90mitch · Mar 14, 2015

200tdi ayre said:
check youve got power there is a good start

Indeed but it would be safe to assume i don't given the pump appears to be doing nothing? Does seem strange though how the fuel level started a little above empty with light on and then soon dropped to nothing with the light off.

I will check tomorrow anyway and the fuses too. Just seems more probable to me I've just disconnected something. just can't see where! off the loom that runs from front to back on the left side of the vehicle I didn't think there was anything to do with the fuel pump there and that it was all underneath. I don't recall disconnecting any wires that didn't have an obvious path (i.e. to a light cluster). the only one being that of one that splits from the light cluster in the bumper on the left side of the truck and goes off somewhere seemingly towards the front of the truck. I tried reconnecting this but nothing. I hate wiring

discool · Mar 15, 2015

The other simple things that maybe or not applicable to your vehicle and will affect the fuel pump supply are, inertia fuel cut off switch has operated, a loose connection from coil to engine EFI ECU or problems with an immobiliser 12v supply to the coil again if u have one.

D90mitch · Mar 15, 2015

discool said:
The other simple things that maybe or not applicable to your vehicle and will affect the fuel pump supply are, inertia fuel cut off switch has operated, a loose connection from coil to engine EFI ECU or problems with an immobiliser 12v supply to the coil again if u have one.

It does have an immobiliser yes, which was on when i tried to start it the first time. after pressing the central locking button once, it was fine. Why would the inertia cut of switch have been triggered if the vehicle has been stationary since I last started it? Indeed these reasons are possible but seems very unlikely seen as though I've been unplugging things.

D90mitch · Mar 15, 2015

Anyway, where is the earth for the fuel pump on this vehicle?

discool · Mar 15, 2015

D90mitch said:
Anyway, where is the earth for the fuel pump on this vehicle?

Via the inertia switch if the Haynes wiring diagram is correct.

As none of us know exactly what wiring alterations or even if the alterations are the reason for the fuel pump not running any suggestions, as I have already stated, maybe or not applicable.

If you believe it is something that you have done, and that's the reason for the engine not starting, then all u can do is recheck your work again.
Although as u say u have done that u may wish to consider looking elsewhere.

200tdi ayre · Mar 15, 2015

give the fuel pump power, if it starts you're fine, i assume you'll be taking the tank out anyway so as long as it runs now it will run later.

D90mitch · Mar 15, 2015

fixed it, was a disconnected earth. Cheers for help

Wont start after wiring

D90mitch

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D90mitch

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discool

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Dippypud

Never Knowingly Understood

jamesmartin

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200tdi ayre

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D90mitch

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200tdi ayre

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D90mitch

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discool

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D90mitch

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D90mitch

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discool

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200tdi ayre

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