I just bought this truck and it needed a fuel pump. The fuel pump was replaced with the wrong fuel pump before. I ordered a new fuel pump, but it is quite different. It has an return and outlet line. The truck only has an outlet line and one that is very small that I was told was a vent. The old pump had a component that didn’t come with the new pump that had to be moved to the new pump. Not sure what it is, but the small line on the truck fits it and that is where it was on the old pump. I connected it up and of course had no line to go on the return on the new pump and the truck is running. I’m afraid to keep running it if its wrong. I’m baffled. Ive replaced fuel pumps before and never had the both return and out take lines on the pump.
Should be just fine to drive.
Fuel Pump Testing for 1993 MODELS
2.5L/4-151 & 3.0L/V6-181
| 1. | Release fuel system pressure as outlined under”Fuel System Pressure Relief. “ |
| 2. | Disconnect5-16 inch fuel supply hose from engine fuel line assembly. |
| 3. | Connect fuel system pressure tester tool No. C-4799B or equivalent between fuel supply hose and engine fuel line assembly. |
| 4. | Activate fuel pump and pressurize the fuel system using the DRB II scan tool. |
| 5. | If gauge reads 13. 5-15. 5 psi, pressure is correct. |
| 6. | If pressure is not as specified, record pressure, then install pressure tester in the fuel supply line between the fuel tank and fuel filter at the rear of the vehicle. |
| 7. | Activate fuel pump and pressurize the fuel system using the DRB II scan tool. |
| 8. | If pressure is 5 psi higher than previously recorded, replace fuel filter. |
| 9. | When no change is pressure is noted, gently squeeze return hose. If pressure increases, replace pressure regulator. If there is no change in pressure reading, problem is either a plugged pump filter or a defective fuel pump. |
| 10. | If pressure is higher than specified, remove fuel return line hose. Connect a three foot hose to the return line. Place other end in a suitable container. |
| 11. | Repeat test. If pressure is now correct, check intank return hose for kinking or restrictions. |
| 12. | If pressure is still above specified pressure, remove return hose from throttle body and connect a suitable hose to the throttle body and place the other end into a suitable container. |
| 13. | repeat test. If pressure is now correct check for a restricted fuel return line. If change is pressure is not observed, replace fuel pressure regulator. |
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