Originally Posted by dljosephson
Just came back from a 900 mile trip with my 82 Turbo 310, running well and no problems. Tank about half full. Took it out for a local jaunt and it seems there are problems with the fuel system, it will run rough, then try to die (sometime succeeding.) It will make full power sometimes but not others. This is one area I've not already been through in this coach. Fuel tank is a custom unit, 105 gallons, made of welded aluminum plate. It's now full. There is a low point drain petcock and fuel from this point is clear with no particles in it.
There is a Racor filter and the engine-mounted filter, replaced both, found nothing untoward in them. Clue: one time, found very little fuel in the filter bowl. That points me toward either a clog somewhere between the tank and the filter, or insufficient suction from the injection pump. The primer pump works fine and is screwed down tight.
I don't think there is a separate lift pump, only the rotary one in the IP. How difficult is it to remove all of this and clean it out? Recommended place to rebuild it? Looks original.
Would appreciate any suggestions from those who have worked on these.
Well diesel is pretty simple, you either have a fuel restriction or an air leak. If you found air in the bowl that is a good place to start. When filters get clogged up power just goes down until it stops. You don't usually lose power and then regain full power then lose power again. That sounds like more of an air leak. Air in the system will clear itself, run rough and miss, until it gets full fuel. I had a bad fitting once that didn't leak fuel, engine ran fine up to about 70% load. When you opened the throttle the engine would suck air and die. Bleed the air and all was good until you powered up too far. It was fun finding that one.
Drive until it starts to cut out and loose power, pull over and shut it down as soon as you can. Remove the top of the Racor and see if it is full of fuel. If the fuel level is not all the way to the top you have sucked air. Look for a loose fitting or a loose clamp on the fuel hose.
If full of fuel you could install something like this. Racor Fuel Restriction Indicator
Put it after the Racor to check for restriction in the filter. Put it before the Racor to determine if there is a restriction in the tank or lines up to the filter.
As a side note the Racor elements are available in 2, 10, and 30 micron ratings. If you put a 2 micron in it won't last very long. It is supposed to be a primary filter to catch the larger particles and the Isuzu filter which is rated at 2 to 4 micron, will stop the finer particles. On my coach I installed a large, about 4"x10", spin on 30 micron filter ahead of my Racor. I use a 10 micron element in the Racor and the factory Isuzu element. I probably have 30,000 miles on the set up without a filter change.
Check for air and restrictions before you worry about the pump.