I have a 1991 Bronco 351w and have replaced almost everything map sensor, tps, icm, redid all the vacuum hoses, spark plugs, new fuel pump. It has trouble at a random going on the highway or any road to stay driving. I will push on the gas pedal and it will start dying on me, basically going into limp mode. Any suggestions.
Vacuum leaks can certainly do that. (Aside from hoses there are vacuum-operated devices and the intake manifold.) Distributor has been replaced, how about the ignition module? Also, have you checked for OBD1 trouble codes?
Yeah I replaced all vacuum lines by the diagram under my hood. Ignition module has been replaced, it came with the distributor and all new plug wires. I recently changed the fuel regulator but haven't test drove it yet.
What kind of shape are your fuel injectors and their seals in? Are they the original items over 30 years old?
Clean or replace the fuel injectors. New fuel filter you didn't mention if it was replaced. New air filter?
I changed the fuel filter and engine temperature sensor and full distributor and it still runs like it's having trouble staying afloat.