Volvo: starting problems with my 92 Volvo 240, haynes repair manual, volvo 240

Question
Hi, its andre again. i went out and got the haynes repair manual for the volvo. i learned how to do the self diagnostic check. i looked up the code that it gave me. the code read 1-2-1, according the manual i have a fault in signal for air mass meter. i don't quite know what that means. what should i check into. one more thing, i was poking around with the fuel lines and i descovered that the car started everytime i tapped the fuel hose going from the gas tank to the pump next to the rear driver side wheel. i think there is a chance that there is a short in the fuel pump wires, i need a new fuel valve with the ball and spring that traps the fuel from leaking back into the take or i just need a whole new fuel pump. pretty inpressive huh. lol. but i here cause i need your advise. what would you look into first? the car ran great today. but everytime i cut the car off i had to tap that hose to get it back started.    
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Followup  

Answer
Andre,
Since you need to tap on the fuel hose to make the main pump run, why don't you have a test light handy and see if there is power to the pump before you need to tap on it. If there is power there and the pump will not run until you tap on the hose, I would suspect the main pump or wire harness is bad. While you are at it test the in-tank pump. Take the hose off the rear of the main pump and crank over the engine and see if there is fuel coming out. The in-tank pump has about 3 or 4 pounds of pressure, that maintains a constant flow of fuel to the main pump.