Defender 90 TD5 Non start....

Got an issue with the lads 90 TD5. No EGR, no cat....

Within the last few weeks he's had starting issues, where its taken ages to get the engine to fire, but once going its been fine. Now its a pain to start, and is cutting out whilst driving.

We checked with nannocom and no faults stored. Whilst turning over the engine managment light starts coming on, and it feels like a fuel starvation issue. Fuel pump, filter, filter head assembly, fuel pipes, injector harness, have been replaced in the last 12 months. Also no oil in the ecu plug... Battery is new and fully charged. Stuck a fuel pressure tester in the temp port, and we get 4 bar with the ignition on. So tonight we replaced the FPR valve with a replacement Bosch unit. Still the same issues. What I did notice is that we get 4 bar on ignition, but when turning over the engine, the pressure drops to next to nothing, and sounds like its starvation of fuel. The replacement fuel pump wasnt a VDO, or genuine, so could this be the issue ? Weve drawn a blank on every other issue...

Any pointers please....

The engine management light will only come on for a few different things - most likely crank sensor but could also be throttle pedal or one other thing (which i cannot remember off the top of my head). Have you tried turning the engine over with the Nanocom reading the engine speed?

A non-VDO fuel pump is always hit and miss. But that wouldn't explain the EML. Also injector seals are a common cause of poor starting, but again you would not get the EML with that. You would get cutting out while driving though

Are you sure it's the engine management light and not the red engine light with the lightning strike through it?

I'll make a video of it turning over. The crank sensor was a thought I had today, whilst driving past Craddocks. But at nearly £180 quid for a genuine, I thought I'd wait.,....

Its a 10p engine, by the way.

tilly2 said:

I'll make a video of it turning over. The crank sensor was a thought I had today, whilst driving past Craddocks. But at nearly £180 quid for a genuine, I thought I'd wait.,....

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OEM crank sensors are fine, I sell a lot of them and not one return or comment about them.

I'll give one a go then.... For around £30 its worth replacing then...

tilly2 said:

I'll give one a go then.... For around £30 its worth replacing then...

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Even if just as a test it won't hurt too much and then get a genuine later, although I have never had any issues with OEM - still carry a spare anyway though!

But the only thing you haven't changed is the injector seals, although you wouldn't get the EML with that. Replacing the actual FPR rather than the whole unit can also be hit and miss - fitting the Bosch FPR into a non-genuine LR fuel pressure regulator often doesn't last long for some reason.

If the EML comes on every time it cuts out/won't start then a fault must be logged somewhere, or at least something noticeable in the live data. It's difficult to advise without seeing the vehicle, people bring these problems in all the time and we've yet to fail in getting to the bottom of them!

If the things already mentioned were ruled out and still no joy try to bump start it without cranking cos there are cases when the starter has an internal issue which disturbes the crank signal and creates a big voltage drop, if it bump starts right away replace the starter motor

My starter interupted the crank signal and took a long time to start, it also put the engine management light on.
New starter motor sorted it out.

tilly2 said:

What I did notice is that we get 4 bar on ignition, but when turning over the engine, the pressure drops to next to nothing, and sounds like its starvation of fuel.

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Can we take it that you have checked that all the electrical connections to the pump are sound and power to the pump remains fine when cranking?
Ditto to the starter motor although that seems to be less likely to be the problem.

New starter was fitted around 6 months ago... New cps ordered.

Ill post up a video of it trying to start... plus readings, etc.

tilly2 said:

New starter was fitted around 6 months ago... New cps ordered.

Ill post up a video of it trying to start... plus readings, etc.

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Have you tried it with Damp Start?

New crank sensor hasnt arrived yet, but, it fired up first time this evening.... several times. Then stuttered, but it was still running. Fuel now sat around 4 bar whilst running, and cranking... Will be looking at some contact cleaner on plugs and earthing headers as well now...

Strange, as when it wont start, the pressure gauge drops to zero, once you try and crank....

To check the pump connections, its a tank out job, so that can wait.

tilly2 said:

Well, it fired up first time this evening.... several times. Then stuttered, but still running. Fuel now sat around 4 bar whilst running, and cranking... Will be looking at some contact cleaner on plugs and earthing headers as well now...

Strange, as when it wont start, the pressure gauge drops to zero, once you try and crank....

To check the pump connections, its a tank out job, so that can wait.

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I am beginning to wonder if there isn't something floating around in the tank that every now and then blocks the "out" pipe. Did once hear of a case where there were bits of "gorilla snot" blocking it and to be found in the pipes leading forward.
In that case it was most likely to have been some idiot decided to try and use silicone sealant when working on the tank. You get this every now and again in the kit car world where we often have to make our own tanks.

Weve had the tank out and cleaned it when the pump was fitted. Thats also when the new fuel pipes were done.

When i get time to do some diagnostics, the thing actually starts properly... the quest goes on this weekend.

tilly2 said:

Weve had the tank out and cleaned it when the pump was fitted. Thats also when the new fuel pipes were done.

When i get time to do some diagnostics, the thing actually starts properly... the quest goes on this weekend.

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You've looked at the fuel pump relay ?

Not yet. I need some spare time, daylight and a strong tea one sugar...

Sorry for not updating this, but its been a busy week....

Replaced the Crank Position Sensor, and so far, its not had any issue starting...... touch wood. Im not 100% convinced its sorted, but so far its drivable. Replacement genuine injector seals are next on the cards....

So, wanting to delve a little deeper into whats causing the issue, can anyone tell me what the TD5 ECU does, if it doesnt get the correct data from the CPS... does it cut the fuel pump, or the injector release pulses or what, to cause it not to start ?

It doesnt cut the pump just the injectors

tilly2 said:

So, wanting to delve a little deeper into whats causing the issue, can anyone tell me what the TD5 ECU does, if it doesnt get the correct data from the CPS... does it cut the fuel pump, or the injector release pulses or what, to cause it not to start ?

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As far as I know it affects the injectors firing. Is the CPS you got still working ok?