Fuel Starvation Issues

Since building the engine and adding the supercharger the lowlight has been pretty reliable. There were some initial gremlins to overcome such as the vastly underpowered generator, but since swapping it out for an alternator things have been fine. Fine that is until the other day.

We had just stopped off at Hungry Jacks (or Burger King as us Poms call it) to grab some well deserved mango smoothies after a day out at the beach, the bus did not want to fire straight up, which I put down to the very hot weather but I managed to get it started and drove off back to home. We managed to get about 200 yards down the road when the bus just stopped.

After an investigation I narrowed it down the a fuel issue as with the fuel hose disconnected and the pump on there was only a small dribble of fuel coming out. Figuring that it was either a blockage or an issue with the pump I called the RAA as there was nothing further I could do at the roadside. Mel and the kids walked home whilst I wanted for the knight on a yellow horse to arrive. Not wanting to sit idly I continue to try and locate the source of the issue and discovered some small pieces of wood that had suspiciously been placed inside the filler cap door. Things were not looking good. My daughter has a habit of sticking twigs and pebbles into door locks and car exhausts, I figured that in all likelihood she had filled the tank up with the same.

When the guy arrived he tinkered around a bit and decided to try to blow back up the fuel line with his airline (it's handy having a compressor in the back of your van) fortunately this managed to clear whatever it was and the bus fired up and managed to stay running. So off I went home in the bus.

After a talk with the kids, who were adamant that they did not put anything in the fuel tank I set about pondering what the issue could be. I decided that I really needed to get the bus fixed and reliable again as I didn't really wanted to end up stranded somewhere. I checked the filter, which along with the hoses were just a few months old, nothing seemed odd there, There was no debris in the filter, the carburetor was obviously not at fault and whilst there could be something in the tank there was no sign of anything in the filter. I decided to replace the fuel pump figuring that perhaps it had somehow worn or otherwise stopped doing what it should do.

So after a visit to my local Autobarn for a generic facet style solid state fuel pump I swapped it over and took the bus for a spin. Everything seemed fine.

The next morning I went to take the boy to little athletics and found that the bus would not start - it had the same symptoms as before - would run for a few seconds but then died (fuel starvation). Phah - just what I need.

After I got back I decided that I really needed to drain the tank out, flush it out and renew all of the fuel lines and the filter. I also could not remember if I had installed the gauze in the tank outlet so needed to check this as well.

Draining the tank was fun as typically the bus had a full tank. Two full size jerry cans and two spare fuel cans were not quite enough to hold the contents so the lawnmower and wifes car got a drink as well. I can also say that it takes about 30 minutes to drain a tank using the fuel pump, it's not a fast process.

With the tank drained I removed the hose and nut holding the outlet into the bottom of the tank. Fortunately it did have a gauze fitted although it was a little dirty (still not really enough to make it block up though). I flushed the tank out to hopefully get any debris out of the bottom and tried to work out if there was anything stuck in there which I didn't really manage to do with much success. With the outlet removed I decided to fit a larger less restrictive 8mm fitting. Unfortunately this was not something that I could buy locally so I decided to make my own. I started off with a NPT barbed fitting and turned off the thread and hexagon part until it was the same diameter as the standard fuel outlet. I then cut it down the size and faced it off smooth. I actually made it twice as thick due to the softer material as it was aluminum instead of steel.

With the new outlet fitted I ran new fuel line and added a new filter before testing everything for leaks. So far everything seems fine but I have to admit that I am apprehensive about saying that the issue is 100% cured as I did not really find anything that could really be considered as the root of the problem. Fingers crossed that is the last time the issue happens, hopefully flushing the tank and replacing the delivery system will be enough. If there is one positive thing to come out of this it has made me realize that my emergency spares kit that I carry in the bus was missing a coil and a fuel pump and that I need to carry an airline adapter for the tyre compressor so that I can blow out the fuel line.