Check the cigar line, that odd shaped line coming from the steel fuel line going into the IP. It gets rotted with age. Remove it and plug one end an blow on the other. Will tell you if it is bad.
Also check the pressure line coming from the very back of the intake manifold and going to the crossoever switch and then on to the top of the IP. That line tends to get gooped up at the manifold end. Needs to be clear to signal the IP to dump more fuel when the turbo spools up.