Thread: Puma 2.4 - Random power loss + engine cut

Hi all,
my son's 2.4 90 Puma has twice had to be flat topped truck home due to cuuting out or initially no throttle response at all, and despite sometimes going for a few more ks dies completely--it is extremely dangerous to be passing a truck and suddenly find all power gone--ie NO repsonse to depressing the accelerator. First time is was a faulty fuel sensor that took ages for the LR service centre to deal with as no faults showed up on the diagonistic readouts, the second time it was the temperature sensor and again no faults showed, but gauge did show overheating --which it certainly was not. Both times the car had recently been pressure washed so maybe thse sensors don't like getting wet--not a good advert for a LR though!

Thank you all for your suggestions.

I would tend to rule out the possibility of overheating, in any case, the CHT sensor has been replaced.
When I mounted the large intercooler I also cleaned the radiator from the engine side. I did not find it clogged, just some dirty on the bottom anyway now it's like new.

After reading what's Brian wrote and suggest, I believe that the most likely cause is that of a problem in the low pressure section of the fuel intake.
I called the shop to ask if they could check and clean the feeding tube section from the pump to the filter head.

As a DIY maintenance, it's ok to remove the fuel filter, detach the quick release coupling from the pump, and spray the fuel feeding tube with brake or carb cleaner and then blow it with compressed air ?

@Alan48: I fully agree with you about how dangerous this kind of failure can be. My nightmare is that the engine stops in a motorway tunnel without emergency lanes...
Which is the fuel sensor that you described ? It's the VCV (Volume Control Valve) on the fuel pump ?

Some update about my issue, I'm very sad

Yesterday I took the vehicle from workshop and drove 465 km to return at home.

The following repair was made:
- CHT sensor replacement
- Fuel filter head + filter replacement
- Tank and fuel lines cleaning + blowing using a very effective tank cleaner
- Total fuel draining and filtering, it was ok, very few dirty inside
- Fuel pump learning
- Immobilizer fully disabled

Engine run really fine for the entire 465 km highway trip, average cruise speed between 105 / 110 km/h, weather temperature was fairly hot, +32°C and sometime +35°C but engine temp (CHT and cooling fluid) was always like expected even with aircon on. CHT Max peak = +105 °C.

To arrive at home, I have to take a 300 mt steep uphill road, I usually drive it very slow in 1st gear with engine at 2000rpm. Just a few meter from the parking the engine quickly loose all power and die. No way to restart it for at least 10 minutes.

No DTC stored except P1935 -Brake switch/sensor signal- fairly common on my Defender

I take the video of the ScanGauge display during the various restart attempt, apparently there was no fuel pressure on the rail. I kindly ask if someone could decode some useful information from the two YouTube videos, expecially from the FPd (Fuel Pump Duty) and FPr (Fuel Pump rail) gauges

Video 1 - restart attempt after about 30 seconds from cut-off
Defender Puma restart failure - 1 - YouTube

Video 2 - restart attempt after about 2 minutes from cut-off
Defender Puma restart failure - 2 - YouTube

The 3rd video will show the ScanGauge values in normal condition, when the engine in turned on and then off without problem
http://youtu.be/3W5Rk6b2Do8

Thanking in advance for any help!

Hello,

Just an update about my defender issue.
I opted a very drastic solution. At the beginning of August I asked the LR assistance to replace the following components:

- Fuel/injection pump with VCV valve
- The entire common rail with both valve/sensor at the end
- All the fuel lines from filter head to engine
- The entire engine wiring assembly
- The ECU

I then drove for about 1000km trying to repeat the conditions that generated the problem (low fuel, steep road, highway etc.). Everything went fine. At the moment I'm fairly happy .

My engine, previously, in normal condition run very fine, but now, with the all the new components throttle response is in some way improved. Another incredible thing happen is that fuel consumption decreased dramatically (from +- 7km/l to +- 10km/l).

Hoping that the problem is finally solved, I keep the finger crossed!

I hope it fixes your problems, were those parts replaced under warranty???

Originally Posted by sashadidi

I hope it fixes your problems, were those parts replaced under warranty???

No, I had to pay for everything

Vehicle standard 3y warranty was expired Sep-2012.
I tried to ask a warranty extension since the problem was complained when the Defender was under warranty but no lucky.

The only thing I get for free is a courtesy car for one week

The problem appears to be centred around fuel supply to the HP pump and then the common rail. The possibility of a faulty High pressure pump on its suction side is very high, to test the theory the pump can be pressurised with a low pressure lift pump from the tank.


Glad it is finally all sorted out

JC

I also think that the problem was caused by the pump, probably in the suction/low pressure section. In that section there are a non serviceable filter and a bypass valve that may be the culprits, who know.

To save money I bough a refurbished "exchange" pump, so the old one was returned to the supplier. No way to test or dissect it to see if something is wrong.

I hope now the problem is finally solved!