C-9 Flames out at low speeds

[Bob Dunlap]

Now, that makes sense!
Thanks for the clarification.
Bob

[Bob Dunlap]

Richard,
I'm in the process of installing the CAT priming pump and a new fuel pressure regulator.  It dawned on me that the priming pump will augment the fuel pump in order to assure good fuel flow to the injectors, but where is the fuel pump?  Is it along the fuel line between the tank and the filters or does it rely on a mechanical pump on the engine.
Bob

[Richard Davis]

Bob
The fuel pump on the C9 is a gear driven mechanical pump on the engine itself.  Dave Atherton has an article in the "Ask Dave" section of the Technical tab called "C9 and C12 Fuel Pump Comparison".  I think you will find that brief article enlightening.
Richard

[Bob Dunlap]

Richard,
Sorry to be such a bother to you, but I need to be sure I'm going about this the right way.  When the CAT priming pump is installed and working, as far as I can see, it will run continuously when the engine is running.  Is that right?  If so, is there a problem with heat generation?  Can it run for hours on end until the engine is shut down?
Bob

[Richard Davis]

Bob
Yes, you are correct.  I had the same concerns before I installed the unit on mine.  Dave assured me it is a robust unit and has no problems running continuously.  The flow of fuel is adequate cooling for the unit.  It runs just like any other electric fuel pump.  I was puzzled as to why CAT made it as a 24 volt powered unit rather than 12 volt powered.  My local CAT parts guy explained to me that the majority of CATs business is off-road vehicles and they use 24 volt starters to start their engines rather than 12 volt.  So us on-road folks have to adapt if we want to use their equipment.  I suppose you know that after 2009 CAT no longer provides engines for on-road use, off-road ONLY.  I took Dave Atherton's word that this was the best solution to address the low fuel pressure (air infiltration) issue on the C9.  Mine has now been in service for about 5 years with no problems.
Richard     

[Bob Dunlap]

We installed the CAT Fuel Primer Pump as described by Dave Atherton.  Our first trip was for about 30 miles to fuel up in preparation for an upcoming trip.  No issues.  The engine got up to normal operating temp and was run at freeway speeds for most of the 30 miles.  We thought we had the culprit licked.  Today, we embarked on our trip and got into downtown San Antonio (about an hour away) and the gremlin popped his ugly head up again.  The engine died and would not restart.  After 3 hours, a CAT specialist arrived and ran a few diagnostic checks.  He determined that the oil pump was not providing sufficient pressure to run the fuel injectors.  Long (grueling) story short, we had it towed to Rush Truck Center in San Antonio where it sits awaiting a CAT specialist to replace the high-pressure oil pump. 

[Bob Dunlap]

After the installation of a high pressure oil pump, the "flame out" problem ceased to exist.  It has plenty of power and no more black smoke.  Should be clear sailing on our next outing.