Chevrolet Repair: 1991 Chevy S-10, fuel pressure gauge, fuel pressure regulator

Question
QUESTION: My S-10 has a 2.5 L 4 cyl auto tran 185,000 miles. the problem I am having is that after the truck sits overnight, I have to prime fuel system in order to start. After I do this the truck will start fine and runs smoothly the rest of the day. The fuel pump at the tank has been replaced and fuel filter has been replaced. Any help would be appreciated.

ANSWER: The fuel pressure regulator may be not holding fuel pressure at the rail.  If the regulator is defective it will drain all the fuel back to the tank and take a bit to feed up.
wayne


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QUESTION: What is the location of the fuel pressure regulator and how can I test it? Is there some sort of diagram you can direct me to? thanks, keith

Answer
The fuel pressure regulator is in the fuel rail up by the injectors.  You need to connect a fuel pressure gauge and start the vehicle.  When you turn it off fuel pressure should hold for a while and not just immediately drop off.  When vacuum is applied to the regulator the fuel pressure will

wayne