Rough idle and will bog out when you let off the gas

Hello, I do not suspect the fuel pump, I suspect either a bad intake manifold gasket, a leaking brake booster, head gasket, failing charging system components or ignition coil/distributor cap and rotor. Check the dipstick for creamy colored oil first, then check the coolant for oil contamination. Afterwards, you can have the coil tested, as well as the complete starting and charging system. If your guy insists on the fuel pump, test for fuel pressure at the engine, and make sure your pressure does not bleed off quickly. In this particular situation, I would recommend having a professional diagnose the vehicle, as the cost of diagnostics is probably less than you have already spent on parts that did not correct the issue.