cummins 250 fuel system troubleshooting

[Vintage iron]

My M813 was losing power, but not all the time. So I have done some troubleshooting.

1. Changed filter, put in diesel injector cleaner.
Result: A little better, but still terrible sometimes.

2. checked emergency fuel shut off, fixed bad wire on fuel solenoid.
result: The shut off was all the way open, but the fuel solenoid wire was ready to break off.

3. try different fuel from different stations.
Result: the truck will run different on different fuels. Low sulfur highway fuel is the Worst.

4. oil and inspect throttle linkage.
Result: Found out the the linkage was loose and bent. It wasn't going to full throttle. Truck is still weak at hi RPM.

5. Clean out tank, disassemble all connections clean them and tighten them, blow out and flush entire fuel system, replaced all rubber hoses on fuel system.

Result: Bingo! the fuel feed hose from the filter was collapsing. The feed hose looked fine but was a little soft and the return hose was dry rotted. So I decided to replace both. I found out the the insulated bracket that holds the hose to the fender support was restricting the hose and it was collapsing under high draw. I replaced both hoses with Aeroquip hose.

Finally the truck runs like it should!

 

[timntrucks]

yes to all you have done. i had trouble with the rubber lines under the drivers seat going to the selector valve.

 

[rumplecat]

MY problem was the fuel line from the filter to the IP, replaced with a line from NAPA and no more hard starts!

 

[MyothersanM1]

I think every 809 series owner goes through this. I replaced everything rubber from the tank to the IP. Been a charm ever since.

 

[ARYankee]

MY problem was the fuel line from the filter to the IP, replaced with a line from NAPA and no more hard starts!

Do you have NAPA part number? I just found my issue and it is my fuel supply line from the filter to the IP. It was kinked and is in rough shape. I'm really surprised that it just started giving me problems.

 

[juanprado]

Ar,

Napa makes up the hoses as they crimp and cut to any spec. Just take it off and bring to NAPA or any HD store that makes hydraulic hoses and they will match one up.

Good Luck!

 

[ARYankee]

Ar,

Napa makes up the hoses as they crimp and cut to any spec. Just take it off and bring to NAPA or any HD store that makes hydraulic hoses and they will match one up.

Good Luck!

Thanks. I'll try that then. I was just some what hesitant on doing that because most of the time you take things to an auto parts store you get the "I have no clue what you want look" and unless it is in their computer system they are useless. The days of competent and helpful folks are becoming few and far between. If I can't get it done at NAPA, there is a hydraulic place fairly close that I will try.

 

[ARYankee]

I got one made at my local NAPA store. I lucked out I guess.

 

[allie]

how do i test a solenoid before buying another?
thanks
al

 

[OkieM1008morrison]

I just replaced the rubber hose from the fuel filter housing to the injection pump on my923 today. looked completely normal from the outside, but inside it was almost all the way collapsed....there's all my lost power!

 

[machinist75]

Did you have to remove the fuel filter housing to get the hose off? The connection to the housing seems to be a booger.

 

[OkieM1008morrison]

yes I took the housing completely off, it has three 9/16 bolts, of course they had been painted multiple times... plus fine thread. made it real fun to take them off. ratchet wrenches are great for tight spots, I love mine for projects like this. I went ahead and replaced the o-ring on the top of the filter housing and replaced the filter housing gasket just because I already had them off.