Persistent "Fuel Leak" error code

[Hooks]

I'm new to the forum and not mechanically minded, so am at the mercy of the professionals. I hope someone out there can point me in the right direction.

Over the past 18 months, my 2009 GLS LWB NT MY10 5SP Auto 3200cc Diesel Turbo Pajero has had a recurrent P0093-large fuel leak error occur causing Pajero to go into intermittent limp mode. Three separate mechanics have found NO visible leak.

Jun 17 the four fuel injection tubes were replaced at MM dealer, car went fine.

Feb 18 same error code, same MM dealer advised replace suction control valve and fuel filter. (This was done through independent mechanic.)

One week later, same error code, still no leak visible. Took to MM dealer and their advice was to keep replacing items until they found the problem. Likely up to about $10,000 in repairs.

Decided to take it to a diesel specialist who also couldn't find any fuel leak. They 'initialised the SCV valve on fuel pump and carried out a small injector quantity learning and did a large fuel leak test on the engine. The vehicle did not fail.'

Their advice is that it may be an electrical issue.

So I've had the Pajero home for another few days and it has again gone into limp mode. Dash image attached.

I would appreciate suggestions of best course of action.
Thanks and regards, Hooks.

[erad]

Probably not much help, but I checked my Max Elery workshop manual and code P0093 says "Fuel leak problem (reducing fuel pressure)" whilst my smartphone app says it is "Fuel System Leak Detected -Large Leak". So it may not be a large leak. Not much help I know, but to my mind, there is a difference in the code definition.

The most likely culprit would be one of the injectors leaking - the fuel would go into the cylinder and you would never find that leak without removing the injectors and bench testing them. Fuel could also be leaking into the engine sump. Have you had any work done on the engine lately?

[shawty950]

Fuel Pressure limiter

Have heard this scenario before and just searched and found this...depending on how old your paj is

Your problem is the spring inside the fuel pressure limiter.

It is either too weak from factory, or you have modified the tune via increased rail pressure. Once fuel pressure inside the rail overcomes the spring tension, fuel will divert back to the fuel tank, causing sudden drop in pressure, hence the "Leak".

Chipit do a "hi spec fuel pressure limiter" for $150...may be worth removing your current one and taking a photo and sending it to them at the time of ordering...when I did my 2011 NT, it was a change over period and the snouts on the limiter were different and had to send it back for the other model.

Shawty

[Hooks]

Persistent "Fuel Leak" error code

Many thanks for the prompt replies.

The "large fuel leak" seems to be the most consistent error type for the code.

I will definitely look into the spring/chipit option as it is by far the most definitive action suggested to me (MM dealers were just keen to keep replacing bits until they found the solution).

Thanks again,
Hooks

[DaveH]

Perhaps a bit left field but if the injector pipes were replaced and they leak, the diesel could be leaking into the engine oil and you may not notice. I have no idea how to test for this but I would not discount the injector pipes totally.

[Hatto]

WAIT! Finally someone with the same issue I had. I installed a cheap chip that I acquired and after doing so I intermittently had the same code and limp mode. Since removing the chip (6months ago) it hasn't come back. I have now plugged the chip back in but on a different setting so far with no I'll effect. One thing I noticed when I was getting the fuel leak codes was that the fuel consumption readout on the dash was reading REALLY economical. Like 8-9 L/100 instead of the usual 11-12L/100. Initially I thought you beauty this chip is gonna save me heaps of fuel but in reality a full tank was going the same distance it always did. But for some reason the fuel economy figure displayed suggested otherwise. So the computer thought it was using less fuel but the engine was still using the same as it always did hence the computer chucking a wobbly wondering where all the fuel savings were going!
Have you got a chip installed? If you bought the car 2nd hand, maybe it already had one that isn't easily visible under the bonnet?

[Hooks]

No modifications to the car, no chips installed or altered (have had since new).

Really appreciate the recommendations.

[wakeboarder]

Check the fuel rail pressure switch connection , had same problem with chip installed . Ended up cutting OE plug from harness and joining it into chip wiring loom . I’ve had error code come up once in 6+ months compared to few times a day

[Hatto]

Ah righto. So is that the plug that the chip plugs into? I think it plugs into the fuel rail area?
It feels like a good connection when I plug it in but I might have a fiddle with it.
What sort of chip do you have? No idea what mine is. It's a blue box with no labels on it. Got it off a forum member who also couldn't give me any info on it. He told me it's not an expensive one though?