TD5 Defender Starting Problems

Hi,

I’m having problems starting a TD5 engine that I rebuilt. It’s in a 2004 Defender.

The engine turns over well and has a new starter motor. All of the injectors click when tested with a Nanocom. No security codes are shown.

I believe that the issue is related to the crank sensor. With Nanocom and Lynx tools, I’m seeing a cranking RPM of 230-230. I’ve seen online that the TD5 needs a cranking RPM above 300 for the injectors to fire. The engine definitely sounds likes it’s turning over well, with a cranking RPM that is equal to or better than a TD5 Discovery I have that starts well.

I’ve tried different crank sensors with and without the NSJ000010 spacer, a different ECU, and a new plug and shielded wiring direct from the sensor to the ECU, with the same 220-230 RPM results.

Any ideas would be greatly appreciated!

Thanks.

Is the fuel pump running, filter ok and system bled, fuel pressure regulator ok, TD5 engines require a really good battery to spin them over fast enough, is the battery up to the job.

The fuel pump is running, filter is new, system was bled many times. I tried adding a new fuel pressure regulator. It has a new large battery, new starter, and I tried with a battery booster pack too. It sounds like it's turning over quite well.

Could be ecu problem. Check the socket for oil, injector harness can leak oil back.

I tried with a different ECU, and had the same results. I've cleaned the connectors and harness. There was some oil at the ECU plug, but I've sprayed the plugs on the harness multiple times with contact cleaner until there were no traces of oil.

Try disconnecting fuel line at FPR and see if you get diesel there.

There is fuel at the pressure regulator.

Timing may be out. Chain might be out a little.

The timing is on my list of possibilities, but my understanding is that the ECU needs to see above 300 RPM for the injectors to fire? If it's only registering 230, wouldn't that prevent starting?

TCI Defenders said:

The timing is on my list of possibilities, but my understanding is that the ECU needs to see above 300 RPM for the injectors to fire? If it's only registering 230, wouldn't that prevent starting?

Click to expand...

My one starts with a cranking speed less than 300rpm so don't get too fixated on the 300rpm for starting (probably an internet fake news story).
If the crank sensor was not working you would not see a cranking speed on the Nanocom.
Has it started since you rebuilt it?
You say no security codes did you mean fault codes?
Is the ECU and the A10s alarm correctly synchronised?
Immobiliser could be engaged.

Yes, mine starts quite happily with a starter that turns it at 260 rpm. So I'd be thinking about other things.

Thanks for the replies.

I have not started it after the rebuild. I tried briefly with starter fluid and it did fire.

The Nanocom showed that it was not immobilized. There are a few fault codes, but not anything that I'd expect to prevent the engine starting. The ECU and alarm control unit are original. Would a Nanocom be able to show if they are not synchronized?

My plan now is to (1) find a gauge to check fuel pressure at the regulator, (2) check the grounding on the shielding for the crank sensor cable (the diagrams show that it's grounded to the black wire that leads to pin 16 on the red ECU plug), (3) check that the engine is grounded well, and (4), and try tow starting it.

The fact that you've got a value for the rpm while turning the engine over suggests that there's enough information getting through to fire the engine.
If the ECU and 10AS are not synchronised you don't get any sign that the immobiliser is on - no warning light or any other obvious indications. On the Nanocom it's under 'engine' and then 'utilities' and then there's a bit that says 'learn security code' (or on some models it may be 'learn DDS code') If you do that it'll prompt you to turn the ignition off and on again and you're done. I spent ages looking for this command under the 10AS menu and wondered why I couldn't find it!

Thanks Brown. I will check the immobilizer and report back.

I checked the immobilizer and went through the learn security code functions, tried with an auxiliary ground to the engine and ECU, and with a booster pack to keep the voltage up when cranking. No success.

What voltage is needed to be maintained during cranking to fire the injectors?

My plan now is to check battery voltage when cranking, check the fuel pressure at the regulator, and the timing.

Hmm. When you say you 'bled' the system did you use the purge cycle - the one you activate by turning the ignition on and pressing the accelerator multiple times? I find that after I have had my fuel system apart it takes at least two full purge cycles to get me going again.

Looking at the data on mine as I start the engine the battery can drop to about 10 or 11 volts and the engine will still start. The casing of the ECU doesn't need to be earthed for it to work - all the black wires going into the multiplugs do the earthing and mine will work quite happily when it is just loosely resting on its shelf.

In the rebuild did you have the timing chain off at any point? I'd be tempted to have a look inside just to make sure everything was lined up as per the manual. I'm sure it will be, but by now I'd be at the point where I'd be wanting to make sure.

TD5 wiring looms as a whole can deteriorate. Not just the injector loom but the whole main red plug loom. I ended up getting a whole new one in 2015. Land Rover seem to have suffered from a batch of wire that was very brittle with insulation that was apt to flake away back in the mid 2000s.

Thanks Brown. I found a gauge and the fuel pressure at the temperature gauge on the pressure regulator is close to zero. I'll start troubleshooting that and see if it's the pump or something else in that system.