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Re: HEUI Fuel injectors - fuel in oil

 
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Re: HEUI Fuel injectors - fuel in oil

My Delimber is 320B excavator, keeps making oil... I have replaced the injection pump 3 times, remaned pump from Caterpillar, It is in 70 hours time its making 5 gallons of oil extra, so we have to change the oil continuously. we have changed transfer pump 3 times also. It has 6 new injectors and nobody has any more suggestions. No blow by, excellent power, starts good. We have talked to Cat Tech.. The Garage in Brewer Maine, 3066 Engine Mitzabichi. This is really a puzzle.. Is there anybody out there that has the same problem. Would appreciate some suggestions.

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Re: HEUI Fuel injectors - fuel in oil

I just replaced the pump on a 320E the seal had blown. This machine only has 730 hrs on it. 

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Re: HEUI Fuel injectors - fuel in oil

Dear cat dealer, thanks for the info.....that is the new skill for troubleshooting. I will looking forwards with that.....Tnx a lot...

Cat Dealer
Dealer

Re: HEUI Fuel injectors - fuel in oil

All of the above  are good techniques. Fine out how much fuel is in the oil by SOS. Depending on your engine model....... We've had good luck by pressurizing the cylinder head fuel galley with regulated air after capping the return port. And checking each injector for signs of leakage. In my opinion 30psi would be a good starting point. Another method is to use leak detector dye with a UV light. This method works best in low light condition.

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Contributor

Re: HEUI Fuel injectors - fuel in oil

hi there....in that case u have to check injector seal for every injector first( visual inspection)..... might be the seal has worn out and it cannot stand the pressure from the cylinder head oil gallery....you also can do injector cut out test to get the correct data for every injectors...

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Re: HEUI Fuel injectors - fuel in oil

This is common failure of C9 injector, inside the injector leaking, not the seal outside. Normaly, you immediately suspect fuel leaks from fuel transfer pump, because it is conected to the HEUI pump. But 3yrs working with C9, I've never met it.

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Re: HEUI Fuel injectors - fuel in oil

Trusted Contributor

Re: HEUI Fuel injectors - fuel in oil

The oil samples should confirm if there is fuel dilution.  If there is fuel in the oil, the engine can have a power issues due to the oil being thined out and the HUEI system not being able to make the correct pressure to fire the injectors properly.  As far as the fuel entry in the system, it is probably the seals on the fuel injector leaking.  It could also be the fuel transfer pump. Is it making engine oil? That would give an idea how much fuel is getting in. 

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HEUI Fuel injectors - fuel in oil

I have a customer that is having issues with fuel in the engine oil in his CAT equipment that is equipped with the HEUI Fuel System.  He feels that the oil is not holding up, so it is not operating the HEUI fuel system correctly, causing the fuel to mix into the engine oil.  His thoughts are based on the oil analysis report, that there is fuel in his oil.  He is using a quality product and changing the oil a bit under the recommended guidelines.  Has anyone had any issues with this?