I got the fuel pump and filter at the same time less than a year ago. The car was stalling before that then it kept on doing that until one day I set the EHA and Lambda. I was stalling free for a few months then problems came back. Now no matter what I do it ain't sticking.
Here is the situation as of now:
1. I cleaned the strainer at the fuel distributor inlet
2. After that cleaning the fuel pressure rose to 4 bar just by shorting the fuel pump relay socket without starting the engine.
3. I put the relay back and then started the engine, the pressure dropped to 3.2 or 3.5 Bar.
4. The pressure SLOWLY went up passed the 5, 5.6 the passed 6.5 bar. At 6+ the car was shuddering.
5. I shut the car down and went to bed.
6. Next day the car wouldn't start (the usual) but after I got going the pressure was still below 4 and climbed slowly to 5.
7. Revved the engine and a loud pop at the plate was heard. Must be running very lean!

My question is this: Shouldn't the pressure on the main line climb to 5.6 bar as soon as the pump is on? engine off (relay shorted), or engine on (relay in place).

The vendor for my fuel pump is willing to take it back and send me a new one. It's a Bosch but it looked slender than my original which unfortunately I had tossed away while clearing up clutter in my garage. Any ideas what I should use to plug the hose coming from the fuel tank while the fuel pump is out and being swapped?