1995 disco v8 into defender- wont start

Hi everyone. I have put a 3.9 v8 into my 1994 200tdi defender. I have it all put back together I'm getting a good spark and runs on easy start( not good I know but just wanted to prove the ignition system) it would appear that the injectors are not opening because the plugs are dry. How does the ecu get it's signal to open the injectors. I have been at this now for months. The discovery the engine and box came out of was mine and had been driving it for 6 months so it was working great when I removed it.

have you got the right fuel pump for system ,does it run for 4 seconds then turn off then come back on while cranking have you got ecu wire on coil that lets system know it should be operating

I would check fuel filter, pump for noise and see if I was getting fuel to the pressure regulator.

Was this good spark nice and white or kind of orange?

Hellooooo OP?

Answer your Q's, we're ready to help!!

Hi. Yeah it's the right fuel pump and it runs for a few seconds And runs when cranking. The spark is a little yellow. It's a new coil plugs leads dizzy cap and arm. I do have the ecu lead on the coil but I don't know if it's on the rite terminal. After taking it out of the discovery and fitting it in the 90 I had 2 multi plugs one white with lots of small wires and a brown one with 7 wires which some control the relays. I don't know how to wire these cables so the ecu gets the right power to it.

is main efi loom earthed on back of lh head ,ecu just needs big brown wire for feed plus ignition white wire (cant rememer stripe colour with both )white purple pump feed

Yeah the earth is on the back of the block the ignition wire is the white/green. If I put test leads on one of the injectors would I see it come up on my meter. Might I fried my ecu by putting a +ve from the battery onto a wire I shouldn't of because I have tried all sorts to of wiring to try and get it to fire. What colour is the wire that comes from the coil to the ecu.

cant remember colour of stripe but eenters main loom at air flow meter branch

It's white with a black trace!

Does it go on the -ve side of the coil.

Am I right in saying the ecu must be getting the signal from the coil because when I turn it over the fuel pump comes on.

I assume so, because there is no starter feed to the ECU.

I think perhaps you just need to recap what you are sure is right and what you aren't and we can try to work it out.

It'll be very simple, always is with these efi v8s.

I'm I right in saying the ecu must be getting the signal from the coil because the fuel pump is coming on when the engine is turning over.

I'm writing these posts on my phone. When I return home tonite I will get on the computer and list what I have and don't have. Thanks for your patience.

phantom221221 said:

I'm I right in saying the ecu must be getting the signal from the coil because the fuel pump is coming on when the engine is turning over.

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But do you know if your getting fuel through the pressure regulator yet?

Their is fuel coming back down the return pipe and I have fuel in the rail because It comes out the "tyre valve" bit on the rail under pressure if pressed. Is their a way to check if the injectors are getting their signal to open.

phantom221221 said:

I'm I right in saying the ecu must be getting the signal from the coil because the fuel pump is coming on when the engine is turning over.

Click to expand...

No, I don't think it works quite like that.

To fire the injectors the ecu only looks for the trigger signal from the coil. There should be a white with black trace wire going on to the negative terminal of the coil (there should also be an in line resistor in that wire). This is the wire that breaks out of the loom next to the air flow meter plug.

You might also find you have idle problems unless you have put the speed transducer in - the signal from the transducer tells the ecu to switch the idle control on and off.

hi. as above i fitted a 1995 disco v8 3.9 serpintine engine and autobox and fitted it into my 1994 200 tdi defender 90. i took the engine out the disco complete with loom, to take the loom through the bulkhead i removed the ecu and 2 multiplugs- one brown and one white. the white one looks like its for all the instuments and the brown one is for the power to the ecu. i cut the brown multiplug and put each wire (7 in total) in connector block. i renewed the coil, leads, plugs,, dizzy cap and rotor arm. its got a good spark- not as good as it could be but enough to run on easy start. the problem is that it will not run without the easy start. the fuel pump comes on for for a few seconds when i turn the ignition on and come back on when i turn the engine over. after turning the engine over for about ten seconds and failing to start when i take out the plugs they are dry. i have half a tank of fuel and fuel comes out the "tyre valve" thing on the rail. because the pump comes back on when im cranking the ecu must be getting the signal to operate the injectors because that is the only way it would know its turning as i used the original starting wire from the loom from the 200 tdi. could the ecu be fried. is their anyway way to see if the injectors are getting the signal.

As far as I'm aware, there is no direct connection between the 14CUX ECU and the instruments - all the main gauges are served directly from engine sensors. You say the ECU must be getting a signal but the injectors aren't firing that suggests either the trigger signal is not being received by the ECU or the injectors aren't grounded - they work on a switched earth, or the ECU is faulty.

I would suggest you download RAVE and study the EFI wiring diagram. It is quite a simple system and it will be something silly if it isn't an ECU fault. If you can, try substituting your ECU for another one - any 14CUX will do they are all the same.

BTW I presume you have the tune select resistor in place?

Hope that helps.

Try reading this, might help.

http://www.landyzone.co.uk/lz/f42/help-3-9-efi-not-starting-108872.html