Cummins 8.3 fuel problems

[Impala_guy]

I have a 94 holiday rambler with a 8.3 cummins my fuel filter had a large crack down the side lost 100 gallons of fuel .. I replaced it with new one from napa less then 100 miles its got a big split on side like the last one ..fuel just dumps out side of it .. What do I do ? Why does it blow side of filter out ? Is there another filter ? Is it causing this one to burst ?

[jtfcons]

There is a small valve at the front top of the injector pump that is spring loaded and serves the function of creating back pressure to the fuel delivery system of the injector pump. Any unused, excess fuel is bypassed back to the fuel tank via this valve. If it fails, the result is loss of back pressure to the injector pump which will likely cause starting issues. If it was stuck shut, I could foresee the problem of excessive pressure in the fuel line from the transfer pump thru the secondary filter and up to the injector pump. The fuel line in this circuit is metal tubing not hose so the weak link could very well be the filter housing. I have not heard of this bypass valve sticking before, more the case of spring failing and loss of backpressure. This valve is cheap and relatively easy to replace if your handy.

A blockage in the fuel return line could also create the problem described but it's rubber and more likely to fail before spliting a fuel filter housing imho.

[Airstreamer67]

I have read that some fuel filters are being made of plastic nowadays.
I would try making sure that the filter is made of metal.

I would also check the fuel pressure to make sure the fuel system is not overpressurizing for some reason.

I would also make sure nothing is hitting or rubbing on the filter to make it split.

Losing 100 gallons of fuel is crazy.

[Fishinghat]

Tom/Barb wrote:
Your lift pump pressure regulator has failed, or you have a blocked return line to the tank/pump inlet.

There should be 2 filters, the chassis filter and the engine filter, which one is blowing out.?

the engine filter is the one attached to the right side of the engine, the chassis filter can be anywhere.

If the engine filter is clogged I do not see how the engine runs.

If the chassis filter is blowing out, I don't see how the engine gets fuel?

The lift pump run 3 minutes after the key is turned on, if it has no return it will pressurize the engine fuel system including the filter to the max pressure of the pump pressure regulator if the return is blocked.

X2

I have a 1993 HR Navigator with the same engine. There are two filters, as indicated above, and the recommended replacement filters are identical. I've never had one fail or leak. Could the filters from NAPA be faulty? If not, then it has to be a failed pressure regulator, and I have no idea where that is located.

[Impala_guy]

Ok man thank you ill go Through the fuel system

[Tom_Barb]

that's the engine filter, it is being pressurized by the lift pump. there is a clog in the fuel system after the injection pump and the return to the tank.

[Impala_guy]

Passenger side of motor u can hardly get to it from the bottom it runs fine just like waterfall of fuel dumping while its running

[Tom_Barb]

Your lift pump pressure regulator has failed, or you have a blocked return line to the tank/pump inlet.

There should be 2 filters, the chassis filter and the engine filter, which one is blowing out.?

the engine filter is the one attached to the right side of the engine, the chassis filter can be anywhere.

If the engine filter is clogged I do not see how the engine runs.

If the chassis filter is blowing out, I don't see how the engine gets fuel?

The lift pump run 3 minutes after the key is turned on, if it has no return it will pressurize the engine fuel system including the filter to the max pressure of the pump pressure regulator if the return is blocked.