Intermittent Fault

Hi all, I hope you're all keeping safe in these unusual times.

I've had my 04 Disco 2 Landmark for about 12 months and have a problem that is bugging me. After having the usual teething problems of ball joints, fuel pump, welding the chassis, new wiring loom from the pedal to ECU, new auto gearbox!! etc I can't seem to solve this one.

Under accelleration she sometimes cuts out but then bursts back into life as if nothing is wrong and it may not happen again on that journey but on the next it will do the same. Some journeys are worse than others but there doesn't seem to be any pattern. I've plugged in my Hawkeyes but have no faults recorded.
Any ideas? Cheers

Hi, when you say it cuts you mean it looses power ?

Petrol or diesel?

Yes sorry, it loses power for a split second then cuts back in again. It's diesel

That seems very like overboost, check the wastegate modulator's pipework and if the valve is not sticking, if everything checks out well visually remove fuse F2 engine bay and take a test run...if it's OK like this replace the wastegate modulator

Thank you. I will give that a go.

Don't forget to pop back and let us know what your findings are.

I sure will. I followed the helpful tips on here about rewiring my accelerator pedal and it worked a treat so can't thank you guys enough.

My Disco has a hold on me that I can't explain!

Nichol71 said:

My Disco has a hold on me that I can't explain!

Click to expand...

That'll be all the superglue you used!

No superglue yet but plenty of welding wire

Good afternoon, an update on the fault.

I checked the pipe work and all seems well. I can't see any obvious breaks in the cables and the modulator doesn't look that old but I fitted a new one anyway.

The fault was still there on a run so I removed the F2 fuse which made the power loss worse. Still no faults recorded on Hawkeye.

Any more ideas?

From now you nreally need to plug in a diagnostic tool... did you check the wategate actuator to not be stuck ? eventually connect a pump to the valve and see if it moves when you pump it to make sure that the diaphragm is not leaking

Thanks Sierrafery. I'll keep you posted on progress.

Forgot to say that I didn't check if the wastegate actuator was sticking so I'll check that too.

I await correction but when it happened to me, wastegate actuator problem, the engine only ran properly again, when the engine was stopped and restarted. So if the intermittent fault happens and then all runs right again a moment later, without a stop-start at the key, I don't think it can be an over-fuelling then limp mode situation.
Wot u think @sierrafery?

@Nichol71 any updates on this?

The only update I have so far is that I've checked the actuator isn't sticking by pumping air into the inlet and it moves smoothly with no sticking at all. I had a spare vacuum hose so fitted that too.

I have a new (not cheap) fuel pump which I bought some time ago as the one I fitted 12months ago was only cheap as I was strapped for cash at the time. I intend to fit this at the weekend with a new filter. I don't know if this will make any difference but it's a job I've been meaning to do for a while.

Do you have any idea what pressures I am looking for from the wastegate on Hawkeye when I take her for a test run at the weekend?

Here you have the list with correct readings https://www.landyzone.co.uk/land-ro...-ambient-air-temp-sensor.365120/#post-5005968

I am suffering from this problem myself ...no codes and I have to turn the key off and on to resolve it or stick it in second and rev hard ......no codes either but I am waiting for my foxwell 520 to arrive.

Ok an update.

So, I have fitted a new fuel pump (VDO) and fuel filter and all seems well. I've done a 40 mile trip with no stutters or farts and smooth power delivery. All the figures you gave me Sierrafery all seem good apart from the Acc supply. I have a reading of 4.2v where your document states it should be between 4.9v and 5.1v. Is this something I should address?