I have an 88 f150 4.9 wen I got it it had been sitting awhile long enough for gas to go had well I put a new clutch in it drove it 2days it shuts down due to rust in tank fixed that put new injectors new FPR plugs wires didn't help it is running rich idling rough misfiring grey exhaust i finally realized return line was folded in half closed totally at tank so fixed that new map sensor but still not to running right have gas coming up in FPR in vacuum lines I'm hoping that maybe I messed my FPR up with return line being kinked and that problem will be fixed wen new 1 arrives also changed out leaking capacitors in computer any thing else I maybe should check???