|
Draining the tank and replacing the fuel filter is a good plan. What comes out with the gas may give you an indication as to whether you need to go further. If the gas has little residue / evidence of rust then there may be no need for further remediation.
A fuel pressure test is the definitive way to evaluate fuel starvation. I think a '73 D jet would run with a rail pressure of 30 psi. Arranging the test so that you can drive the car can be a little tricky. I did this once on my B20E by using an oil pressure gauge, flex nylon tubing and some brass fittings to tap into the cold start valve line. I duct taped the gauge to the cowl in front of the windshield so I could watch the pressure while I did a couple of full throttle shifts up to about 100 kph. If the pressure holds steady; but, you are loosing power then the problem is something other than fuel supply. If you see the pressure drop at the same time as you have power loss, then you know you have a fuel supply problem.
Your problem can also be caused by a tired fuel pump. If the pump is getting tired, the increased suction head requirement caused by a drop in fuel level in the tank can result in loss of flow and low pressure (remember the D jet pump is not a submerged pump like modern cars).
I did the POR treatment on my 142 B20 E gas tank. 10 years since I did the treatment and no issues have emerged. However, I cut large holes in the roof of the tank so that I could media blast the interior of the tank and then patched those holes with the top of a donor tank from a non D jet car (there were no reproduction tanks for 140 D jet equipped cars). I then did the degrease and acid treatment before applying the coat. A fair amount of work. If repro tanks had been available I would have gone that route.
|
