LIMP MODE, POSSIBLE FUEL PRESSURE ISSUE

[joeymudslinga]

Hey everyone,

I am having issues with my ML GLX-R. Several months ago I ran the car pretty much dry and ever since the engine light has been coming on and off. When the light comes on the car goes into limp mode. The code the computer is reading is P2127, pressure limiter malfunction. Mitsubishi have bled the fuel lines, replaced the fuel filter as well with a genuine part, but the problem still occurs. The next step the computer is telling them is to replace the common rail assembly and tubes. I have asked them questions regarding other possible ways to fix the problem but they seem to have no understanding of why this keeps happening and they cant guarantee the common rail replacement will solve the problem. To replace these parts is quite expensive though and I wanted to know if there was another way to go about it or if there is another solution?

The engine light comes on when the revs go over 2,000rpm, up until 4th gear. 4th and 5th are fine with the revs over 2,000 the car doesn't go into limp mode. I just wanted to know if you had any insight into this problem because the people at the Mitsubishi dealership said they have never come across having to replace the common rail before on one of these vehicles. The car runs fine if I keep the revs below 2,000 and the problem doesn't occur all the time, it comes and goes.

Any tips or information on who can help would be greatly appreciated

[hvac guy]

Did they say if the fuel pressure was too low or too high

[Cowboy Dave]

I wonder if you'd have any luck putting in a high spec rail limiter from ChipIt? I'm far from an expert but with that code it sounds kind of logical.

[Tony]

If you like, I can send you a spare chipit remanufactured fuel pressure limiter to try. (Unfortunately denso only supply them with the complete rail assembly, this is whey they say you may need all common rail assembly and tubes )
Also, there is a small filter on the side of the denso pump that some forget to inspect and clean.
If that doesn't fix the issue, I would have major concerns about the common rail pump its self as may be leaking off due to running dry. I hope not for your sake.

Send me a PM if you need any help with this as the dealers can not supply this pressure limiter part alone. be worth a try.

They are $120 retail from chipit by memory.

If the pump turns out bad news, I can help you source an exchange unit though chipit.

Cheers,
Tony

[joeymudslinga]

Did they say if the fuel pressure was too low or too high

I asked the mechanic that question who had been working on my car at mitsi and he didn't know all he could say is that I'm just following the computer steps. I thought there would hav been some general knowledge in the workshop, I guess not these computers are taking over. All he said was he had to keep bleeding the lines because there was air in the fuel.

[joeymudslinga]

If you like, I can send you a spare chipit remanufactured fuel pressure limiter to try. (Unfortunately denso only supply them with the complete rail assembly, this is whey they say you may need all common rail assembly and tubes )
Also, there is a small filter on the side of the denso pump that some forget to inspect and clean.
If that doesn't fix the issue, I would have major concerns about the common rail pump its self as may be leaking off due to running dry. I hope not for your sake.

Send me a PM if you need any help with this as the dealers can not supply this pressure limiter part alone. be worth a try.

They are $120 retail from chipit by memory.

If the pump turns out bad news, I can help you source an exchange unit though chipit.

Cheers,
Tony

I might try that out its cheaper than replacing the whole assembly they wanted 2k. I was driving my car this morning because I took the car off them and the car is pulling forward and back slightly and reving up and down whilst driving.

[snowman]

Did they say if the fuel pressure was too low or too high

I asked the mechanic that question who had been working on my car at mitsi and he didn't know all he could say is that I'm just following the computer steps. I thought there would hav been some general knowledge in the workshop, I guess not these computers are taking over. All he said was he had to keep bleeding the lines because there was air in the fuel.

mate they are clearly clueless and want to throw new parts at it without having any real knowledge. this is the scary part of car ownership and MITS dealers i reckon.

Sorry Lee, you are a rare breed, but unfortunately a minority.

take it to someone who has a clue. see what options you have to your location on this site.

[Lee-thal]

First of all, they need to identify where the fuel is becoming aerated,

this is easily done with clear hose before and after Fuel filter,

this is the first step for them, then they can keep going,

If the fuel is becoming aerated before the fuel filter then i cannot see how the rail can be the issue.

maybe its as simple as an air leak somewhere.

[Tony]

I would hope the dealer in question would have done the basic steps before announcing you may need a new rail assembly etc.
Running out of fuel shouldn't harm the pressure limiter, so something else is likely a miss.

As Lee-thal has suggested, an air leak or restriction before the pump must be ruled out before changing any parts.

Don't let anyone replace the entire rail, there is no need!

[joeymudslinga]

First of all, they need to identify where the fuel is becoming aerated,

this is easily done with clear hose before and after Fuel filter,

this is the first step for them, then they can keep going,

If the fuel is becoming aerated before the fuel filter then i cannot see how the rail can be the issue.

maybe its as simple as an air leak somewhere.

ok guys so i have taken my car to hi tech diesel injection theyve had it for the last 3 days!! they have finally found the problem. they found contamination in the fuel filter after being replaced 3 days ago. there was metal and a mouldy substance in it. there was no air before or after found when a clear hose was attached. so the outcome is a new suction valve or a whole new pump. they dont guarantee if i change the valve the problem will go away but if i change the pump it will. they have also quoted me on disassemble the fuel tank and give a thorough clean and adding another aftermarket double filter system. im not sure whether to just change the valve which is the cheaper option or to do the whole pump? the valve fitted with everything labour etc is $1600 or the pump + labour etc is $2600 the labour is $1400 alone so the parts are only worth $1200 but i guess they have been working on the car for th elast 2-3 days they said soo yeah.. the pump alone is $1000. any recommendations on what i should do?

[hvac guy]

Have they given you any idea on the fuel pressure in psi

[joeymudslinga]

Have they given you any idea on the fuel pressure in psi

Yes they hooked it up to the computer and took it for several test runs and the Pressure was all over the shop too high then low.

[hvac guy]

That p2127 fault code is accelerator position sensor error

one of the guys on here had erratic fuel pressure problems and turned out to be an scv valve
but its up to U to decide which way to go.

[Tim007]

Let's hope it not the same reason as mine with PETROL being put in a DIESEL truck That will [censored] your rail pressure (and a whole lot more) up real quick.