Questions and Answers
Can't Take The Pressure
Q. Hello, Its me again! I've got another question. The mechanics that are working on my 86 F 150 (5.0L 302/FI) are stumped. They say that there is twice the pressure in the fuel line, and its dumping fuel in the cylinders. They replaced the O2 sensor and the EGR valve (both were showing bad codes) along with the fuel pressure regulator. It's still doing it. They were going to check the fuel pump to make sure the diaphragm wasn't stuck wide open. I don't think they found the problem. Please help!!!!!
Derek
A. There's two reasons why you would have excessively high fuel pressure, a bad fuel pressure regulator or a bad fuel pump. Since the fuel pressure regulator has been replaced, that narrows down the options quite a bit.
Why a mechanic would replace an O2 sensor and an EGR valve to correct a high fuel pressure problem is beyond me. While they might be throwing a code, they in no way directly effect fuel pressure. Maybe you should consider another shop.
