M20 nightmare. Not starting, no fuel

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brennon
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Post Sun Mar 02, 2014 4:47 pm

Having a nightmare with the car!

M20 with monotronoic injection

Not getting fuel to start.

Turns over fine, getting spark.

Wasn't getting power to the fuel pump so put a live on it.

Getting fuel to the fuel rail but no further, plugs are dry.

How do I find the fault, clearly electrical as injectors are not opening but where should I check?

Possible causes are the oil pressure sensor is not connected and the ecu is not bolted to the car (should it earth through the housing?!)

Having a nightmare with it so any help is apriciated!!
maxfield
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Post Sun Mar 02, 2014 4:59 pm

Have a look for corrosion around the plug under the inlet manifold.
Image
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brennon
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Post Sun Mar 02, 2014 6:14 pm

I'm really struggling to remember a plug under the inlet manifold, what plugs into it? Easiest way to spot it?
Grrrmachine
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Post Sun Mar 02, 2014 6:32 pm

trace the injector loom from the fuel rail, down under the intake manifold, where it plugs into the rest of the engine loom. Corrosion here will knock out the injectors.

However, I don't think that's going to be the problem. I think it's more likely that your DME relay has failed.

For a more comprehensive series of tests, read this:

http://www.e30zone.net/e30zonewiki/inde ... oubleshoot
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Brianmoooore
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Post Sun Mar 02, 2014 9:18 pm

Any chance the relays are in the wrong sockets?
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brennon
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Post Mon Mar 03, 2014 12:20 pm

i had a look into the link above about troubleshooting.

where the ecu plugs to the loom i have 3 wires coming out that link up somewhere close to the ecu, this isnt my exact loom but a spare i had at home as i can't get to the unit today.

Image

mine differs in that the green wire has its own seperate plug.
Is this the +12v to power the ecu?
should it be ignition live or constant live?
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Brianmoooore
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Post Mon Mar 03, 2014 1:44 pm

Only ancient M20s have that plug, and those that do, don't have the plug and socket referred to under the inlet manifold. What build year are we dealing with here?
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brennon
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Post Mon Mar 03, 2014 2:26 pm

It must be an early one, the injection system was retro fitted to e21 so I can't give specifics :(

Is it just a case of put an ignition live up the green wire?

At the moment it's left unplugged!
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brennon
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Post Mon Mar 03, 2014 2:58 pm

Image

Does that help with what age system it is?
Speedtouch
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Post Mon Mar 03, 2014 3:08 pm

Yes, that's a pre-facelift 320i L-Jetronic (analogue) ECU, not the later digital Motronic.

http://www.e30zone.net/e30zonewiki/inde ... st_of_ECUs

Check Fuse 11 for the fuel pump:

http://www.e30zone.net/e30zonewiki/index.php/Fuse_Box
///M aurice
ECU Upgrade EPROM Chips, £40 posted within the UK. Note these are not Zone chips.
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