CAT 299D Fuel leakage code...

[Makers Acres]

I started a new thread on this as the last one was resolved, and was due to fuel contamination, but this seems to be from a new problem.

My Cat 299D is now throwing "Engine Fuel Leakage 1 - Error Code 1239-1".

This time, I tried changing the fuel pump, fuel filters, and even blew into the fuel line to make sure it is clear. Watching the fuel pre filter, it appears I have good fuel flow. I even tried running the machine on an external small tank just to be sure, and the issue still happens.

I put my old pump on a test bench and it is making 15PSI. The new pump makes 12PSI. I have tried both pumps in the machine and they don't seem to make a difference.

One thing I have observed is that this problem happens more when the machine is warmed up.

I thought maybe this was related to injectors, so I tried a deep seafoam cleaning, and the engine seems to run a bit smoother, but still shows the error.

Thanks for the help!

 

[HeavyTech]

Hours?

 

[HeavyTech]

You have a 3.8 with common rail system

From my experience providing all fuel filters / pump etc are good with zero restrictions it is the pressure sensor on the common rail

 

[Makers Acres]

Hours?

3800 hours on the machine.

 

[Makers Acres]

You have a 3.8 with common rail system

From my experience providing all fuel filters / pump etc are good with zero restrictions it is the pressure sensor on the common rail

Can one get just the pressure sensor on that rail? Cat wants to sell you the entire rail for $1200 last I checked.

 

[Nige]

Can one get just the pressure sensor on that rail? Cat wants to sell you the entire rail for $1200 last I checked.

The pressure sensor is not available separately based on all the information to which I have access.

 

[HeavyTech]

Sorry for the late reply

Yes you can buy the replacement oem pressure sensor from the manufacturer/ dealer that makes the sensor.

Example: Bosch - Denso

You will have to inspect the sensor and get the information off of it

 

[HeavyTech]

Sorry for the late reply

Yes you can buy the replacement oem pressure sensor from the manufacturer/ dealer that makes the sensor.

Example: Bosch - Denso

You will have to inspect the sensor and get the information off of it

Although it is recommended that you replace the entire rail, I have used this method many times before and had zero issues or leaks. The new sensor has thread lock / sealant already on the threads do not add extra sealant.

 

[Makers Acres]

Does anyone know if the pressure sensor will need any calibration with the main computer?

 

[Makers Acres]

Sooo... The mystery continues. I replaced the the fuel pump yet again and the problem went away for about 4-6 hours running at full power. Then the issue came back slowly. First every 20 minutes or so and now I can't run the machine in full throttle and put any heavy load on it. What the hell!

 

[lbv40995]

you figure your problem out? My machine is doing the exact same thing and running out of ideas.

 

[lbv40995]

My problem ended up being in the fuel relief valve on the rail said these machines have a manual valve and won’t throw a code but return line was really hot so replaced that and fixed the problem

 

[HitachiEX]

My problem ended up being in the fuel relief valve on the rail said these machines have a manual valve and won’t throw a code but return line was really hot so replaced that and fixed the problem

I am having the same problem that you were having, was there a blockage in the return line from the relief valve or do you know why it was getting hot?

 

[Makers Acres]

you figure your problem out? My machine is doing the exact same thing and running out of ideas.

No, sadly I have not found the source yet. I have a theory now, but haven’t had time to validate it.

I finally had a conversation with someone who worked at CAT and they thought this was most likely related to the fuel injectors. They suggested I find someone with a CAT laptop, but the shop wants 4 hours minimum at $218 an hour to do this.

It seems the fuel injectors share a common oil rail that is sealed with an o-ring. This can leak and cause the fuel pressure to drop.

I bought all new seals for the injectors (About 35$) but I have not had the time to put them in yet.

 

[Makers Acres]

Pulled the injectors.... Wow, that was hard to get too. Who's bright idea was it to use two valve covers and put an exhaust pipe across the rear two valve cover bolts?

Here are a couple pictures of the injectors....

 

[Nige]

That looks like the results of an engine that has spent far too much of its life idling or at low engine loads. These engines seem to perform better when run hard most/all the time.

 

[Makers Acres]

Ya, I have had no choice with the error code. Hopefully rebuilding them will fix my issues.

 

[Nige]

Hopefully rebuilding them will fix my issues.

FYI. Anecdotal evidence suggests there is a shortage of fuel injection specialists who will not only rebuild these injectors but ALSO stand by their work.

Talking to a Kubota engine dealer might be a good first step.

 

[Makers Acres]

Thank you, I have noticed that. This is why I am going to send them to area diesel service who I have watched a few YouTube videos from and they have impressed me.

 

[Nige]

TBH a company having a Youtube channel would make me less likely to deal with them. Smoke & mirrors and all that.
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