Diesel Fuel Contamination

Paul Owner Georgia Posted   Latest  

Truck towed in. Customer states it started running rough. Hooked up scan tool and had multiple miss fire codes. Went to start vehicle, long crank, ran rough and died. I noticed the fuel gauge read almost full, so I knew my first check. Tank didn't smell right, but couldn't confirm for sure. Pulled sample from water separator and confirmed my fear. E85. I have been able to save these before (This is a company truck. I wouldn't do it on an outside customer). I drain and drop both tanks, clean them and reinstall. I flush fuel lines, and prime system with clean diesel. Truck starts up but still has multiple misfires, with high fuel trims on affected cylinders. I know what GM says, but what are y'alls must replace parts, and what is the go to for cleaning lines, ect. I know we sometimes have better procedures than OEM. It doesn't want to let me input VIN. 1GDE5C1989F… GMC 5500 6.6

0
Troy Owner/Technician
Washington
Troy
 

My thought would be just injectors if you have good vacuum at the pump just could be the injectors got to hot and done if the pump sucks good it should be ok

0
Ð Awarded
Kevin Technician
Alberta
Kevin
 

Just like Troy said most likely the injector started to break down, on the up side its better to have 8 injector than a injector tip breaking up which bring the dollar figure up. Offer your customer to replace the affected cylinder but between you and I they all seen the same punishment. Having a injector let go after 2 weeks will bite you in the butt

0
Ð Awarded
Albin Diagnostician
Washington
Albin
 

Many times when a common rail fuel system gets loaded with gasoline, it kills the whole system. If you stick a set of injectors in, and the high pressure fuel pump is trash, then you get to do the injectors all over again, on your dime. You can pull the fuel metering valve out of the high pressure pump and check for any metal trash on the screen, and if there is any at all, then start with the…

+2
Ð Awarded
Agree
Ryan Owner/Technician
British Columbia
Ryan
 

I'm with Albin. You should look for metal inside the fuel system. Check the top of the fuel filter, once removed, and take a sample from the high pressure side. Being an LMM with a CP3 it is less likely but still possible. I have seen may Duramax engines survive gasoline, look for other possible issues like rust as well. You may be dealing with two issues.

0
Ð Awarded
Paul Owner
Georgia
Paul Update
 

I always go through the fuel system on any contamination issue. I never trust the pump after something like this, especially when it doesn't run correctly after cleaning tanks and priming system with good fuel. I was just wondering if anyone replaced anything unusual after a problem like this, or had any good tips or tricks they do when flushing lines.

0
Update Ð Awarded