I took my Foed F150 (V8-281 4.6L SOHC Automatic) for an engine diagnostic test because it would turn on but as soon as I took my foot off the gas to shift to drive it would shut off. I was told I needed a new fuel pressure regulator. I had the work done but it is still not completely turning on like it used to. It feels like it wants to shut off most of the time and has completely shut off a couple of times. Any suggestions.
It sounds more to me like the IAC motor is not working. Which is the (Idle Air Control ) this device is used to make the truck fast idle it is also supposed to keep the truck running when you turn the A/C on it has a few functions and a the need to be taken off and cleaned they get clogged with carbon and can do there job. On the 4.6 they are mounted on top of the intake right in plain site it is a several cyclinder looking thing with two wires attached to it and it has two 5/16 headed screwes holding it on. Hope thsi helps better than you were getting.(NOS) 8)