P0088 Code (Common Rail High Pressure) and limp mode fun

casm · **Joined:** Sun Jan 29, 2006 5:05 pm **Posts:** 694

Just experienced the joy of code P0088 (Common Rail High Pressure) and limp mode at 75mph on the freeway. Needless to say, it was not fun when that happened in the middle of a lane change to get to a left exit with an RV barreling down on me from behind.

There are no other codes relating to the fuel system. In fact, the only other code is P1140, which is to be expected as I have a Stage 1 Weeks Kit without GDE tune in place.

Anyway, I've done some reading up on the code and wasn't able to determine anything that might be a definite cause. Fuel system (as far as I know) is completely stock, so no in-tank lift pump. Fuel filter head is the revised design with the blue plug. Fuel filter was last changed... At some point in a previous owner's tenure with this vehicle. Tank is roughly five-eighths full. Engine temperature looked as normal as it ever does with the thermostat being shot (please, God, let my HDS t-stat get here by Saturday). Ambient temperature was around 55degF.

Stopped at the local boozeteria on the way home. Parked for 10 to 15 minutes; came back out, started up, everything is normal. If it was high fuel rail pressure, this makes sense since that may have given it time to normalise.

Only recent change was a fresh PCV puck and hose last weekend, but I can't imagine either of those having anything to do with it - and it's been running fine all week.

Any ideas? I'm stumped. Nothing like this has happened in the roughly 4500 miles we've put on this Jeep since we got it.

flash7210 · **Posted:** Thu Dec 21, 2017 8:38 pm

Could be the fuel rail pressure sensor going bad.
Or a loose connection at its harness connector.

Or it could be that the fuel rail pressure solenoid briefly got stuck for some reason, cleared itself out, and when you restarted all was well again.

casm · **Joined:** Sun Jan 29, 2006 5:05 pm **Posts:** 694

flash7210 wrote:

Could be the fuel rail pressure sensor going bad.
Or a loose connection at its harness connector.

Or it could be that the fuel rail pressure solenoid briefly got stuck for some reason, cleared itself out, and when you restarted all was well again.

OK, I can run with all of those ideas, and thanks. I'll start researching how horribly-expensive (and time-consuming) doing the pressure sensor and solenoid will be.

The plan for now is to drive it and see if it happens again. A new fuel filter is on order, but won't be here for a few days given that Christmas is pretty much here.

Apart from the above ideas, about the only possible cause I've found that makes sense is air in the fuel lines. Checked the priming pump and it was rock-solid, so suspect that's probably not it (or, if it was, it cleared itself out). Any ideas as to the likelihood of this one?

(FWIW, I am planning on doing a lift pump, but that's going to happen in the Spring when I won't freeze my booty off installing it.)

GordnadoCRD · **Posted:** Fri Dec 22, 2017 5:10 am

casm wrote:

flash7210 wrote:

Could be the fuel rail pressure sensor going bad.
Or a loose connection at its harness connector.

Or it could be that the fuel rail pressure solenoid briefly got stuck for some reason, cleared itself out, and when you restarted all was well again.

That's a pretty comprehensive list.
Definitely check the connectors and loom before anything else.
When you shut the key off, the power regulating the Fuel Pressure Solenoid at the rear of the rail opens circuit, and immediately dumps all rail fuel pressure into the fuel return line.

OK, I can run with all of those ideas, and thanks. I'll start researching how horribly-expensive (and time-consuming) doing the pressure sensor and solenoid will be.

It's a little more expensive than servicing everything yourself, but this is quicker, comes with all new sensor and solenoid pre-installed, doesn't require special tools, comes with a warranty, and these guys won't try to cheat you on the core charge or make you wait forever. Just swap the complete assembly and ship yours back.

The plan for now is to drive it and see if it happens again. A new fuel filter is on order, but won't be here for a few days given that Christmas is pretty much here.

Apart from the above ideas, about the only possible cause I've found that makes sense is air in the fuel lines. Checked the priming pump and it was rock-solid, so suspect that's probably not it (or, if it was, it cleared itself out). Any ideas as to the likelihood of this one?

(FWIW, I am planning on doing a lift pump, but that's going to happen in the Spring when I won't freeze my booty off installing it.)

flman · **Posted:** Fri Dec 22, 2017 5:27 pm

Put it in park and put the pedal to the metal and shut it off, this will open the solenoid with high pressure in the rail and help flush it out.

casm · **Joined:** Sun Jan 29, 2006 5:05 pm **Posts:** 694

GordnadoCRD wrote:

That's a pretty comprehensive list.
Definitely check the connectors and loom before anything else.
When you shut the key off, the power regulating the Fuel Pressure Solenoid at the rear of the rail opens circuit, and immediately dumps all rail fuel pressure into the fuel return line.

Electrically, things look sound - nothing visibly loose or damaged. Next-most-likely possibility to my mind is that the Fuel Pressure Solenoid may be starting to show signs of age.

Quote:

It's a little more expensive than servicing everything yourself, but this is quicker, comes with all new sensor and solenoid pre-installed, doesn't require special tools, comes with a warranty, and these guys won't try to cheat you on the core charge or make you wait forever. Just swap the complete assembly and ship yours back.

I like that idea. Not really in budget right now, but we'll see if there's any further decline and if there is this may end up being the route I take.

Driving it yesterday on the same route at the same speeds didn't reproduce the problem, so thus far it's just an anomaly. But it is one that I'd prefer to not have turn into a 'surprise! You're stranded!' moment.

WWDiesel · **Posted:** Sat Dec 23, 2017 12:10 pm

If you want to ensure all the moving parts like the Solenoid in the fuel system are clean and well lubricated, add a quart of cheap (non-synthetic) 2 cycle oil to your fuel tank along with a few ounces of diesel fuel conditioner!
This will add additional lubricity to the diesel fuel to help protect expensive moving parts internally like the CP3 and injectors that totally depend on diesel fuel for lubrication.

Some diesel owners like myself have been doing this for years routinely at every fill up along with a few ounces of Power Service Diesel Kleen or Stanadyne Diesel Cleaner.... :wink:

casm · **Joined:** Sun Jan 29, 2006 5:05 pm **Posts:** 694

WWDiesel wrote:

If you want to ensure all the moving parts like the Solenoid in the fuel system are clean and well lubricated, add a quart of cheap (non-synthetic) 2 cycle oil to your fuel tank along with a few ounces of diesel fuel conditioner!
This will add additional lubricity to the diesel fuel to help protect expensive moving parts internally like the CP3 and injectors that totally depend on diesel fuel for lubrication.

Some diesel owners like myself have been doing this for years routinely at every fill up along with a few ounces of Power Service Diesel Kleen or Stanadyne Diesel Cleaner.... :wink:

That's not a bad idea. I did run some Diesel Kleen through it shortly after we got it, but that was probably 3000+ miles ago at this point. A second dose couldn't hurt.

That said, there's also a fuel filter on its way to me as I type. May just prime it with a 50:50 mix of fuel and Diesel Purge, toss the remainder of the Diesel Purge in the tank, and see what that does.

WWDiesel · **Posted:** Sun Dec 24, 2017 10:18 pm

casm wrote:

WWDiesel wrote:

If you want to ensure all the moving parts like the Solenoid in the fuel system are clean and well lubricated, add a quart of cheap (non-synthetic) 2 cycle oil to your fuel tank along with a few ounces of diesel fuel conditioner!
This will add additional lubricity to the diesel fuel to help protect expensive moving parts internally like the CP3 and injectors that totally depend on diesel fuel for lubrication.
Some diesel owners like myself have been doing this for years routinely at every fill up along with a few ounces of Power Service Diesel Kleen or Stanadyne Diesel Cleaner.... :wink:

That's not a bad idea. I did run some Diesel Kleen through it shortly after we got it, but that was probably 3000+ miles ago at this point. A second dose couldn't hurt.
That said, there's also a fuel filter on its way to me as I type. May just prime it with a 50:50 mix of fuel and Diesel Purge, toss the remainder of the Diesel Purge in the tank, and see what that does.

Don't forget adding the non-synthetic 2 cycle oil, it plays a very important part in the lubricity of the of the internals of the fuel system... :wink:

P0088 Code (Common Rail High Pressure) and limp mode fun

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