I have an 85 Cadillac Seville with the 4.1 V8. The engine seems to hesitate when accelerating and does not seem to have the same get up and go as it used to. When its been running for a while it has problems restarting if shut off. Through testing ant such we found that we were only getting 5-6 psi to the engine through the fuel lines. From what we have found it should be more like 9-11 psi. We have tried replacing the fuel filter in case there was a blockage of some sort but have the same issue. Is this something that would cause the car to be underpowered? Has anyone had a problem like this that may have some ideas on where to check for this?