Topic: Check your fuel lines!

[Sasquatch]

Last weekend I took a trip with my father to Sun Valley, ID to watch supercars run top speed runs. This is what happened:

Sometimes God gets our attention to save us from disaster...On the way to Sun Valley the coach acted like it ran out of gas.  Pulled to the side of the road to diagnose.  Could not find any issues with the fueling system at all.  Plenty of fuel, filters flowed well (scientific blow test), etc.  Then it fired up and got us to our destination without issue.  But I could not leave it at that.  Something happened.  In the camp ground I went through the entire fuel system step by step and found a frightening thing.  The high pressure fuel line right at the engine had split all the way down one side.  They had not started leaking yet, but it was right there ready to go.  This would have sprayed 50psi fuel right on the right side of the motor.  Can we say fire danger?  A run to the parts store and 4' of fuel injection hose later and it was repaired.The coach came home without a fuss, never missing a beat even in the 100 degree temperatures.  You can chalk it up to coincidence, but I believe God got my attention with the fuel issue knowing full well I would inspect the entire system before returning home.  I can say with confidence that not only do I believe that we would not have made it home (the splits were that deep), that my pride and joy would have been lost to fire, maybe even claiming the lives of us and one or more of my two cats riding with us (my only children).
A side note.  This is the first time I towed my car since I installed the injection system.  I flat tow a 2001 Mercedes ML430 SUV.  This rig is over 5,000 lbs.  (I use a Remco lube pump for the transmission).  The trip was about 50% freeway where I ran 65 mph, and 50% mountain two lane roads where I ran 55-65 mph.  I averaged 6.8 mpg.  Pretty impressive.

[legomybago]

Good find on your split fuel line, but what caused the engine to die?

Those are great #'s on mph and mpg's. If I were to put a toad on the back of my FMC, I would be climbing hills at 35 mph....

[Rickf1985]

You were running 50# on the original low pressure fuel lines?!!! Fuel injection line is different line for those with carburetors, much thicker and stiffer. Very lucky!

[Sasquatch]

You were running 50# on the original low pressure fuel lines?!!! Fuel injection line is different line for those with carburetors, much thicker and stiffer. Very lucky!

No I was not.  I installed high pressure lines when I installed the fuel injection system about 6 years ago.  The lines that split were made by Eaton Corp and were rated for 300 psi and supposedly fuel rated (I purchased at a hydraulic shop).  They may have been fuel rated, but maybe not ethanol.  I am not really sure.  But any way, I replaced all the Eaton lines with standard FI lines that are in fact alcohol rated.

I have no idea why it quit on me.  Fuel pump was running but no pressure (I have a gauge on the TBI).  I suspect that maybe the pre-filter was slightly dirty and creating some cavitation in the pump.  I replaced that filter in camp (I always carry spare fuel filters).  But it made it home in temps that were 20 degrees hotter than when it failed with no issue.  So I still think God was doing me a favor.

I am going to add some more heat reflective insulation on the fuel system any where it can absorb heat just in case.  I am also going to pick up a spare fuel pump to keep in the coach. 

[Sasquatch]

Those are great #'s on mph and mpg's. If I were to put a toad on the back of my FMC, I would be climbing hills at 35 mph....

I have been quite pleased with how this coach has turning out.  On one moderately long climb on the freeway I only lost 5 mph at the top with the boat anchor (Mercedes) behind her.  I can not wait to pluck the motor out and rebuild it to see what more gains can be had.  As of now the 440 has all the bolt ons done to it, but the low end (minus the cam) are the stock low compression bits.  I want to get it up to around 9.5:1 compression which should net me some decent gains in power and efficiency.

[growe]

God is Good!!! 

[Rickf1985]

How far is your pump from the tank and is the exhaust anywhere near the fuel line is that section of line between the pump and the tank? Most times it is better to put a shield between the heat and the line but not around the line. example, wrapping the line with foil or insulation. A simple piece of sheet metal painted silver on the hot side placed between the line and the heat will do more than wrapping the line since the airflow over the line will do a lot to cool it.

[Sasquatch]

Good information here.  Thank you.  The fuel pump is at the lower edge of the tank.  It is gravity fed by the tank as the lines come off of the bottom, into a large metal canister style pre filter then into the pump, into a FI filter and then to the motor.  I even installed a ball valve so that I can shut off the fuel supply to change filters.

The exhaust and the fuel system run parallel for about 24" with about 8" separating the tail pipe and the fuel pump/filters.  While I have about 10k miles on it this way, I am not above saying that this could be the problem.  My plan is to wrap the exhaust pipe (single 3" tube that is straight) with muffler wrap in this area.  I will also do what you say and build a divider shield with sheet metal between the two with plenty of air space on either side.  I have a brake, shear and plenty of stock in the shop to do this easily.

I am also considering building a skid plate for under the tanks and install insulation between the plate and the tanks to shield some of the heat radiating off of the pavement and keep the fuel in the tanks a little cooler.  But that is probably not going to do anything in the grand scheme of things.

I am trying to keep my expenses in order because I need 6 new tires before the RV season next year.  That is a big ticket item that can not be avoided.

[Rickf1985]

Just keep in mind that the exhaust wrap retains moisture so unless you have high grade stainless pipes the wrap will cause them to rot out pretty quick. The heat of driving drys it out but as it cool condensation sets in and gets the wrap wet and then the pipe underneath just soaks until it gets hot enough to steam it out. If it is an easily replaceable straight section that is no big deal and I would do the same thing.

Same thing with the insulation under the tank, once it gets wet it will stay wet and rot out the tank. The plate is a good idea but i think the air moving by does a good enough job of cooling that the insulation is not needed. Just remember, anything you add is just more weight that you are probably overweight by. They are ALL overweight. 

[Winnebago Warrior 94]

glad you found the cracking fuel line ..I believe like you that sometimes god has things happen for  reason ..sometimes we might break down or be late but sometimes its better than the alternative ..glad your motorhome kept on rolling ..safe travels to you