1977 Volkswagen type 1 bug 1600 fuel inj just doesn't accelerate

1977 Volkswagen type 1 bug 1600 fuel inj. Mileage: 80,000. About ten years ago dad bought my car from original owner and I drove it for about 6 months with no problems until I had a head-on collision damaging the right front fender. I joined the navy and the car just sat in the driveway until I got back home 4 years later. Dad and I got the body fixed and I changed the oil. I started hearing a knocking sound and took it to a shop. They said my bearing was worn so I got a new crankshaft and had a back-yard mechanic put it in. Since then, I’ve been trying to keep my car running. It starts fine. It just doesn't accelerate. When I try to place it in a gear and go it just putters out. I performed a test on the air cleaner and checked the potentiometer and it checked fine... Thank God. But, I can’t figure it out....I don’t know if it’s electrical or mechanical. This engine is such a good engine and everybody's telling me... Stick a carburetor in it......... I’d like to fix it... Its a fuel injected car. I don’t want to modify it... Can you help me please, I’m so frustrated. I replaced the spark plugs and set the gaps to according to the book I think its 0. 28 inches and replaced the sparkplug wires as well. I’m suspecting the auxiliary air regulator. I also had the timing set TDC with a strobe light and everything.... The car still won't accelerate........... I’d like to just drive it down the street that would make me happy after about ten years............ Hehehe. I’m beyond frustrated............. I’d appreciate some advice.