Fuel System Problems

[BroncoTex91]

I'm having problems with my fuel system on my '91 5.8 XLT Bronco. Is there a fuel pressure regulator inside the fuel pump housing in the tank, and if so, why when there is a regulator on the fuel rail on the intake? Does anyone know where I can get diagrams online?

 

[BLADE262US]

There is no regulator in the tank . The regulator is on the drivers side back of the intake mounted right in the fuel rail and has one vacuum line going to it . I do believe a 91 has 2 fuel pumps ( I Know an 89 does ) There is a low pressure delivery pump in the tank and a high pressure pump in the frame rail drivers side at the front of the drivers door . If the one in the tank goes bad it will start hard and if you run it completely out of gas it probably will not start again for loss of prime . What kind of problem are you having ????? /emoticons/[email protected] 2x" width="20" height="20" />

 

[BroncoTex91]

After realizing the Bronco was getting 5 miles to the gallon I started diagnosing fuel system problems. I had 14 psi of fuel pressure at the rail so fuel delivery was not a problem. Disconnected fuel return line next to fuel filter, turned key and had proper fuel return from engine. Found fuel return line going into fuel tank was blocked. Removed fuel tank and fuel pump assembly and disassembled fuel pump assembly. Found a pressure relief valve in the return circuit of the pump. Disabled relief valve, reassemled and ran engine. Fuel mileage has returned. So what is the purpose of the relief valve in the pump?

 

By the way, it does not have a secondary fuel pump, it has a single fuel pump in the tank.

 

[Swat]

Should be 45lbs for fuel injection bro! I didn't know there was a releif valve at the pump. Was it clogged?