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1969 Mark Fuel Pump Issues - Update from May 2012...

Hello Bill & Chris,

On May 29 2012 you will see my email to you guys. I had to walk away in disgust at that time and left the Mark sitting in the garage. Since the motor rebuild no I mean entire car rebuild it will not run properly because of lack of fuel to the carb. I replaced the fuel pump 3 times with a new Airtex 6878 fuel pump. The car will sometimes run, sometimes start but eventually quit running after 15-30 minutes. Everything is new and I mean everything, it is cooling properly, it runs great when it runs. I removed the fuel line to the pump from the tank. I attached a hose to the fuel pump and dropped it into a gallon of gas under the car. I detached the fuel line at the filter on the carb and stuck it in a jar. Cranking for minutes on the starter yielded a tablespoon of gas in the jar. My motor mechanic was convinced it was the eccentric. After months of hesitation I called him and we have torn down the front of the motor. The eccentric he installed, thinking it was better was the 2 piece Ford eccentric. I will say it has play in it. Is there to be a washer
behind these two cam rings??? I have no idea. My 69 Technical Data manual for the Mark III shows a one piece eccentric. IS THIS MY PROBLEM my car requires the 1 piece cam??? Or the fact there is suppose to be a washer behind the 2 piece cam?? Now it gets more interesting, NO AGGRAVATING to the point of profanity ! My George said to throw away the Airtex fuel pumps, it's garbage made in Mexico. Go buy a Carter. I have
searched for a Carter fuel pump. When I find one it says Carter M6878, fits 1970-71 Mark III, NOT compatible with 1969. It there a difference in fuel pumps for 69s ?? I called Robert Ballard in Orlando and he said he knew the timing covers were different between the years of 69 and 70 and maybe the fuel pump was positioned differently on the timing cover not allowing the arm on the newer aftermarket pumps to come in proper contact
with the cam. Mac said on his Marks he never had a problem. I'm sicken with not knowing what the problem is. We have the 3 Lincolns and I'm mechanically capable. I have NEVER had such an ordeal with fuel delivery as I have had on this car. At this point with all the time, effort, and expense I really wanted to keep it original as Ford built it, that's just my nature.

Lord HELP !

Patrick in east Texas.


Hi Patrick -

Your email regarding this problem earlier this year is still remembered by us and I had hoped that it would have been resolved by now. After reading your recent email several times though I don't completely understand your test. You state that you removed the fuel line from the tank. Does that mean that you drew the gas for this test through the fuel lines to the pump at the tank area or did you draw from a short temporary hose properly installed near the fuel pump itself thereby bypassing the fuel lines and hoses from the pump to the tank? If you drew fuel for the test near the pump and then cranked the engine a properly activated pump would have drawn ample fuel and delivered it to the carburetor via the outlet lines and through the fuel filter. Performing that test near the pump eliminates the possibility of a plugged line or an air leak in the suction system between the pump and the fuel pickup in the tank. If the test was performed in this fashion and the pump still did NOT deliver fuel I can only surmise from where I sit that the pump is faulty or that the pump rod is not being activated correctly by the original design at its location in the engine. I can tell you honestly that the fuel delivery design on these engines has never been a problem area and that any fuel delivery failures have always been easy to diagnose in my opinion. I believe that your tests are possibly not being done exactly correct or something obvious is being overlooked somewhere. We cannot determine from here if your fuel pump cam eccentric is activating as designed or if anything has been incorrectly altered in this area on your engine. I am sure of and trust that you or your mechanic already has the correct manuals etc. with explicit photos of the various workings and installation components of the camshaft and the fuel pump. We can offer to test one of the so called "garbage" new pumps for you or we can supply you with a new pump that we are having 100% success and zero complaints with. Beyond that we would need to be on site with the car to do the diagnosis. Let us know how you would like us to proceed in order to help you further.