Saturday, Sep 07, 2013 at 00:08
Pezza - O.K., let me see if I've got this right. The 2.8D Isuzu engine is the 4JB1 model with mechanical fuel injection (no electronics), right? That eliminates any electronic glitches or a need to reach for the OBD (On-Board-Diagnostics) reading tool.
It would pay to
check the following before going to a diesel specialist.
(1.)
Check that the fuel priming pump isn't leaking. If this pump develops a leak, it will allow fuel in the filter and lines to return to the tank when standing, and admit air to the fuel.
Upon startup, and upon the initial couple of minutes running, the engine will run normally, then the air in the lines will find its way to the pump and injectors and make it hesitate and appear to be suffering fuel starvation (which it is, it's getting, say 80% diesel and 20% air).
(2.)
Check for pinholes in any steel portion of the fuel line between tank and filter. Steel fuel lines are notorious for developing pinholes from rust, particularly where dirt sits against the fuel line. The dirt holds moisture and corrodes the line and pinholes develop.
The diesel might leak out a little, but be hardly visible. What happens is the fuel transfer pump commences to suck fuel from the tank, but it sucks in air from the pinhole/s.
The air goes to the pump and injectors and you have a similar result as (1.) above.
(3.)
Check for a blocked suction screen in the fuel tank. Fuel tanks have a nasty habit of gathering crap - rust, dirt, water, textile and fabric trash from rags. All this comes from 13 yrs of use, and hundreds and hundreds of fuel tank refills from dirt and water-containing, drums, jerry cans - and gasp - dare I even mention it - underground fuel tanks! (yes, service station tanks!)
The screen is usually a fine mesh screen that fits over the end of the suction pipe in the tank. It can become clogged with a combination of all the above, that creates a rusty, clogging mess. A clogged suction screen will produce the same result as a clogged fuel filter.
(4.) If it's a steel tank (can't recall if the Rodeo has a plastic or steel tank),
check for pinholes in the top of the fuel tank. Holes in the top of the tank will admit dirt, dust and water to the tank, and cause fuel line and filter blockage, as above.
You can do a pretty simple
test for pinholes by removing the fuel cap, grabbing your air compressor hose with a blow gun attached, wrap a rag around the blow gun nozzle, and insert it in the filler pipe.
Operate the blow gun to pressurise the tank with some air, while you hold the rag and blow gun tightly in the filler neck. You don't need much pressure - 3-5psi or 20-35Kpa. Don't overdo the pressure. Get a helper, and tell them to listen for air hissing out, or fuel weeping out.
I hope this gives you some ideas on
where to start.
Cheers - Ron.
AnswerID:
517760