Defender TD5 wont start

Hi guys - been out of a green oval for a year myself now but trying to help a friend with his

Its a W reg defender td5 that drove fine this morning but was then parked up for a few hours and now cranks but wont start.

The main symptoms I can confirm are the temperatue gauge reads 75% hot with the ignition on and the fuel pump cannot be hear priming at all.

Have checked all fuses (dash and under seat) and all seem ok although under seat are slightly coroded hower they are showing 12 on each side.

Yellow relay under the seat seems ok, black one had the large thick wire loose in the holder but a temporary bypass does not seem to affect anything.

Tried removing and refitting the engine bay inetria switch but no change there.

Cleaned the injector loom connector and the red ECU plug as best as I could with only paper towel. Also seperated the ECU and although no oil inside there is certainly signs of damp where the pervious owner has had it apart before and no resealed it (slight greening on some solder and the big nuts on what I assume are the two big capacitors have light rusting).

In my head im thinking either the ECU is not turning the fuel pump on or the fuel pump has given up - niething of which are easy to do im assuming ?

Does anyone have any ideas / info to help us out or does anyone local to Somerset fancy some beer tokens to have a look, lend a Nanocom or lend an ECU ?

Seems the ECU is not switching earther / lives correctly or its not got any to switch after todays diagnostics !

Power at the interia switch and bypassing the switch makes no difference.

Lift pump works with a direct earth and live.

Also kept tracing it all the way back to the plug by the expanson tank and can still run it from there.

The traced it to the green relay in the centre console and can run it from there. The relay also tests ok but its not getting triggered at all.

Traced from the green relay to the ECU and can manually run the pump with a 12v and earth from the ECU connector so either the ECU is not switching earths / lives correctly or it has none going into it to be able to switch.

It starts to try and run on easy start however even if I have the pump running and crank it over it dont even try so guess the ECU is not opening the injectors either ?

run a new clean earth to the ecu under the seat, find an original and double up to a new earth point, should be a spare stud in there. and earth the ecu case as well. Worked for me when mine did much the same after providing a jump start to someone else

Tried giving both the ECU case an earth and the spade connector that is bolted to the botttom of the drivers seat base one.

I also have 5 earths at the ECU (darker plug) on the 5 black wires at one end of the plug

unscrew the fuse box in front of the gear lever and try pulling out the relay on the right hand side and then re-fitting it again.

Can you hear the fuel pump prime now?

Nope

Thats the green relay I believe ?

If so it has 12v waiting to be sent to the pump and the pump pin has contuninty right back to the pump.

The two smaller switching wires of that relay go back to the ECU and have contuinity to the plugs (one goes to black plug and one to red).

Putting voltage and earth to those pins with the ECu not connected runs the pump via that green relay.

Paulpen said:

Nope

Thats the green relay I believe ?

If so it has 12v waiting to be sent to the pump and the pump pin has contuninty right back to the pump.

The two smaller switching wires of that relay go back to the ECU and have contuinity to the plugs (one goes to black plug and one to red).

Putting voltage and earth to those pins with the ECu not connected runs the pump via that green relay.

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whereabouts in Somerset are you?

Im Taunton chap

The Defender is stuck a few miles north of me.

Paulpen said:

Im Taunton chap

The Defender is stuck a few miles north of me.

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What's the chance of you being around during Tuesday afternoon?

Slim as I work until 5

I can prob arrange the mrs to be around though depending on what you are planning !

ratty said:

What's the chance of you being around during Tuesday afternoon?

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I've got to pop down to Burnham-on-sea area on Tuesday afternoon and thought about popping down if I have time as I will have both a Nanocom and a snapon Modis on board my landy. Unfortunately I'm on nights this week so start work at 6pm.

Sorry for the late reply chap - internets been down

Thats an awesomely kind offer

I expect I can arrange for the mrs to be there at any time you need along with the key etc if that would be any good ?

Or would you be so kind as to let me bring this ecu to you and try it on yours to see if it does work or not ?

I had a similar issue recently - cranking but not firing.
My fuel pump was running My problem was ecu not seeing the cranksensor. You should get a crank reading even when just turning over. This is the only sensor that will shut down the engine.
For me it turned out that inside of the ecu had become water damaged. When I unscrewed the lid this was quite obvious.
Note my lid had been off before and was well stuck on with silicone. If previous owner has had the lid off maybe it got dunked in the water.

With Nanocom you can do a series of tests, these just send a pulse to the various components. If you do fuel pump, then listen for the relay clicking. You know the pump runs when feeding a permenant live, will the engine start like that?

Note if you swap ECU's you need to set the ecu to learn security. It should start and run rough. If you code the injectors it will run smoother. For the injectors, the last letter represents a number- I think A = 0 but you need to confirm this. You will find it on this forum.
As for ECU codes - I got another ECU with the matching code. I don't know if they are interchangeable. A disco one won't work in a defender.
110 ecus having higher torque than a 90.

Hope it helps

Ta for the info

I believe ratty had a diagnostic system which would greatly help narrow the issue down its just working out when is best

Even if I'm running the pump off a separate battery and cranking the engine there is still no hint of wanting to start so I'm guessing that the injectors are not firing maybe ?

Paulpen said:

Ta for the info

I believe ratty had a diagnostic system which would greatly help narrow the issue down its just working out when is best

Even if I'm running the pump off a separate battery and cranking the engine there is still no hint of wanting to start so I'm guessing that the injectors are not firing maybe ?

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You're welcome to test your ecu on my landy if you want.

I'm working nights all of this week (6pm to 6am) so am around during the daytimes. I can sleep as and when during the day so am flexible on that count.

As I say, I'm due to pop down to the Burnham on sea area tomorrow.

By the sound of it, it may be more beneficial for you to be around when the nanocom is present as you can see what is going on or what has/hasn't been checked.

Are you at work every day this week?

PM sent

Massive thanks to Ratty and Fanatic for coming out to have a look and it seems the plot thickens !

Immobiliser system seems ok.

ECU wont communicate with Nanocom etc but we are suspecting that due to it not powering up.

They spotted that there are a few dry solder joints in the ecu on the back side of it so they could possibly be the issue ?

There is a issue with an earth between the gearbox and the body as linking them with a jump lead imporves the voltage at the under seat fuse box dramatically. But problem still seems the same.

Fuses, relays, supplys and earths all test ok and whilst fiddling with bits in the drivers seat pan the pump did run for half a second but we have been unable to recreate that

It did seem that when you take the handbrake off the guage drops slightly though ?!

Although we have voltage and earths with a multimeter at the ECU plugs they advised I restet them with some load so am getting hold of a test light thing and hunting a correct ecu pinout to work with to do that.

So in summary we still have the following symptoms when the ignition is on :
No fuel pump priming
No engine light coming on
Temperature gauge reading 3/4's
Wont start even with fuel pressure applied manually

We came to the conclusing thats its pretty much wiring or ecu so more wiring checks required

Ruari said:

As for ECU codes - I got another ECU with the matching code. I don't know if they are interchangeable. A disco one won't work in a defender.
110 ecus having higher torque than a 90.

Hope it helps

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I have a Discovery ECU (NNN) on my 2001 110 TD5, you have to bugger about with a Nanocom to sort a few bit's & pieces out but it runs a treat !