Info for Bump starting a TD5 and checking injectors with a Nanocom

Back on the TD5 Defender, this time with a nanocom and I'm still struggling to get it to fire.
It's had a recon gearbox before I got to it. when I put the Nanocom on it was showing zero RPM while cranking.
I discovered the CPS was not plugged in DOH. Multiplug connected and it's now showing 200rpm when cranking.
The fuel pump is running when the ignition is on.
It appears that the injectors aren't firing at all as it doesn't even attempt to fire.
I've cleaned the terminal that runs from the starter to the injector harness, replaced the injector harness, had the ECU checked by ECU Testing. The Nanocom shows no faults standing.

I'm wondering, is it possible to test fire the injectors with the nanocom and if so what's the process?

Also, in order to rule out a faulty starter motor stopping the injectors firing, I've read a couple threads suggesting bumping the vehicle off.
What is the process for this? Is it as straight forward as just ignition on and tow it off and drop the clutch?
I thought I had read that you may need to remove the starter solenoid and turn the ignition to crank as you drop the clutch?

Any thoughts gratefully appreciated!

All I did was 2nd gear, ignition on, tow it and foot off the pedal when you're ready.

Just seen this

Pigglet said:

it's now showing 200rpm when cranking

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it must get above 250 rpm to start, see the battery voltage while cranking, if it drops below 10.5V it will hardly start cos it needs more to open the injectors

Pigglet said:

is it possible to test fire the injectors with the nanocom and if so what's the process?

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it's in the "Outputs" menu last line... better read the user guides available here https://www.nanocom-diagnostics.com/downloads

Brilliant, thanks for the reply. Its a new battery and fully charged and was only showing 220 rpm at the first attempt. Voltage was 12.7.
The crank position sensor speed reading was stable with no apparent interference/fluctuation. so I thought it was ok. The starter sounded pretty quick so I thought it would be OK. Perhaps the CPS is on it's way out and reading low.

I will try bump starting it in second gear and see if that gets it to fire.

I have found the injector test function on the nanocom and have gone through each injector and get a 'click' sound from the injector when I press the test button. I was wondering if it is possible to remove the injector from the head and test fire it to see if it is actually firing fuel.

I will go back to it later today and have another mess around now that I know that it needs to see 250rpm or above to fire the injectors.

Pigglet said:

Voltage was 12.7.

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was that while cranking? ...cos that's the only relevant reading... also dont try to crank it when you try to bump start it

I tried bumping it off today and it managed to fire but only just. The battery was fully charged and showing 12.7 volts when towing. I let th eclutrch up in second and it span up to around 1750rpm and ran very lumpily with the throttle fully open.
At either lower RPM (tow speed) or anything other than full throttle it wouldn;t attempt to fire so I'm guessing it's a fuelling issue. The Nanocom is still showing no fault.

When I turn the ignition on the fuel pumps is quite noisy and runs for about 20 seconds before cutting out. I've done the purge cycle etc. I did try checking the voltage across the fuse and thought it was ok before I started this process but I'm now suspecting the pump.

Pigglet said:

I let th eclutrch up in second and it span up to around 1750rpm and ran very lumpily with the throttle fully open.

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You are not supposed to push the throttle once it fired up untill it didnt idle a bit on it's own and if it started once and ran no matter how never touch the throttle without engine already running cos you flood the engine, insisting to start it without knowing a corect procedure can prolonge the symptom, see that bolded note

Thanks for the reply Sierraferry. I did initially try it without touching the throttle but it wouldn't fire at all. I then tried it with the throttle open which got it to fire but then took my foot off the peddle and it died instantly. The only way it would run was with the throttle fully open and then it was lumpy and not on all cylinders. It wouldn;t even attempt to fire at speeds below 1500rpm.I tried multiple runs with various throttle positions, starting from closed and working to fully open. It only fired when I tried it with the throttle fully open.

I've tried the above procedure and it won't fire.
I'm going to order a new CPS as that is only showing 220rpm with a new battery, fuel pump, regulator and non return valve and see what that does. The vehicle had been stood for 3 years so I'm guessing the pump is past it's best.

Pigglet said:

I'm going to order a new CPS as that is only showing 220rpm with a new battery

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I must insist for the last time to measure the battery voltage WHILE CRANKING, the fact that the battery is new is irrelevant if there is a draw while cranking for some reason and the voltage drops more than 2V it will not start

sierrafery said:

I must insist for the last time to measure the battery voltage WHILE CRANKING, the fact that the battery is new is irrelevant if there is a draw while cranking for some reason and the voltage drops more than 2V it will not start

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Thanks again for replying Sierrafery. I will check the voltage while cranking tomorrow when I go back to the vehicle.

The voltage dropped about 1.5V while cranking.
My gut feel was it's a fuelling issue (given it would only attempt to fire while bumping
at full throttle and high revs) so having worked through the easy/obvious stuff I pulled the pump out of the tank. It was noisy and I was suspecting it's not producing full pressure.
There was bit of black bio gunk on the strainer on the bottom of the pump but not loads.
The inside of the tank was pretty clean as was the fuel.
Hmmm, Given the pump is noisy I'll strip it down........... got nothing to lose at this point as there are no other obvious faults..




I think I've found the issue.....
The inside of the lower cage was full of gunk and the gauze strainer above was absolutely choked.
I wiped the pump clean and got the thick thick off the gauze before removing it from the pump.
The LP intake was spotless under the gauze filter so it had done it's job. I've cleaned it all, drained and cleaned the tank and changed the filter and pressure reg. Just waiting for a new pump lock ring before I refit it and see what happens.

Pigglet said:

The voltage dropped about 1.5V while cranking.
My gut feel was it's a fuelling issue (given it would only attempt to fire while bumping
at full throttle and high revs) so having worked through the easy/obvious stuff I pulled the pump out of the tank. It was noisy and I was suspecting it's not producing full pressure.
There was bit of black bio gunk on the strainer on the bottom of the pump but not loads.
The inside of the tank was pretty clean as was the fuel.
Hmmm, Given the pump is noisy I'll strip it down........... got nothing to lose at this point as there are no other obvious faults..
View attachment 346218

View attachment 346219

I think I've found the issue.....
The inside of the lower cage was full of gunk and the gauze strainer above was absolutely choked.
I wiped the pump clean and got the thick thick off the gauze before removing it from the pump.
The LP intake was spotless under the gauze filter so it had done it's job. I've cleaned it all, drained and cleaned the tank and changed the filter and pressure reg. Just waiting for a new pump lock ring before I refit it and see what happens.

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So, do you have any idea what on earth that gunk is?

It's basically the diesel tank equivalent of algae. Biological matter that grows in the diesel. The vehicle has been stood for nearly 4 years so without any agitation or fresh fuel its probably provided ideal growing conditions. It's not that uncommon. Some of the more expensive fuels have biocide added to prevent it growing.

Pigglet said:

It's basically the diesel tank equivalent of algae. Biological matter that grows in the diesel. The vehicle has been stood for nearly 4 years so without any agitation or fresh fuel its probably provided ideal growing conditions. It's not that uncommon. Some of the more expensive fuels have biocide added to prevent it growing.

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Thanks.
I have chucked stuff into the tanks of all my vehicles that are lying idle. Not in the country so I cannot check the bottle out.
Is that likely to have prevented it? I think it calls itself "fuel conditioner" blue stuff, as far as I remember.

Coming back to this after a couple of weeks and it's still not running. The fuel pump is now very quiet with much better pressure at the regulator but when bumping it off it still won't fire.
So basically the same fault still exists. It cranks, will fire with a squirt of easy start but only runs on easy start, there is clearly no fuel being injected.
One thing I have noticed after bumping it off is that the alarm sounder is chirping (albeit very quietly) under the front wing. As it's a county it has the alarm/imobiliser. The fob operates the central locking and removes the immobiliser to allow it to crank BUT I wondered if there is an alarm/ immobiliser function that is holding out the injectors. Does anyone know if the immobiliser impacts the start logic in any way other than stopping it cranking. In short, is it possible the Lucas Imobiliser unit is holding out the injectors?
Annoyingly the Nanocom I hired only had engine functionality (this wasn't made clear when I hired it) so I have not been able to interogate the Lucas immobiliser unit.
So to recap, It was driven into the workshop circa 4 years ago with a gearbox issue.
Gearbox was eventually recon'd after being stood for a couple of years.
The fitter couldn;t get it running after the gearbox was replaced. I discovered the Crank position sensor wasn;t connected properly as the nanocom showed no crank speed when I first connected it so assumed this is why they didn't get it running when it went back together.
I have replaced the injector harness and cleaned the fuel system up to the injectors.
I have had a nanocom on it and it shows no faults on the engine. The ecu has been to ECU testing and declared OK.
Test firing the injectors using the nanocom produces a tick/click noise at each injector.
Under cranking the battery voltage (new battery, fully charged) drops by around .4 to .5 volts according to the nanocom but the engine only reaches 220-225 RPM. I've tried to bump it off to rule the starter out. Crankshaft position sensor appears reasonably stable giving what appears to be relatively sensible and stable speed reading under both cranking and bumpstarting.
Cylinger balance looks uniform while bumping as does airflow voltage readings.

By "bumping" do you mean a start caused by pushing or towing it? Which is what most people mean by that, or do you mean a "jump start" i.e. leads from another battery, preferably connected to a car that is running?
I think I am right in saying that that rpm under cranking will not start it.
So I'd be tempted to take the starter off and service the contacts, or replace it with a known good one. At that voltage I don't think the batt is the problem.
Before taking the starter off, which is a royal pita in itself, I'd check all the leads to it and the engine as dodgy connections/earths could also be the problem.
While on that, remove the positive lead to the starter, tighten the nut UNDER where the connector goes, then replace the connector and its nut.
Best of luck, fella!

Pigglet said:

In short, is it possible the Lucas Imobiliser unit is holding out the injectors?

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Yes it's possible, too bad that the nanocom you hired didnt have the alarm menu in it cos at this point it's very suspect if you say the alarm is sounding and you really need to check if the ECU receives the 10AS security code otherwise it's "locked" and will not open the injectors ...

here are the relevant parts of the 10AS immobiliser functions: