Well the truck is a 94 f150 4x4 5.8 e4od. The Problem is that when I start it it runs super rich and runs terrible. Sometimes it decides to start running good and then it'll stay good till I turn it off but it doesn't always do that. I had a low fuel pressure problem and fixed that with a new fuel pump and it was shortly after that that this problem started to happen. Does anybody have any idea what the problem could be?

 

Check the vacuum line to the fuel pressure regulator for a fuel smell. There shouldn't be one.
If there is, the regulator is leaking internally (and pumping raw fuel through the vac line).
A possibility.
Also faulty 02 sensor could cause that.

 

Alright I can't believe I didn't even think of vacuum lines. Its probably that as I've had a few other vacuum lines break on this truck.

 

Finally figured it out ... I accidentally knocked off the vacuum line to the egr an now it runs great so I just capped off the line