How did this turn out for you guys? I'm having the same problem, same codes. In the Autozone parking lot, replaced one VTC solenoid and the MAF, cleaned & disconnected/reconnected everything possible, & reloaded the modded and stock tunes, but the problem didn't go away.
The symptoms are similar to what has already been reported in this thread. At cold start, the engine is fine. As it heats up, +100 degrees, it surges and idles down low and then runs rough with tapping coming from the valve covers. It sounds like it has cams with a mean lope, but mine are stock. Power is weak and I have to give it a lot of gas to get the RPMs up and get it to move. There is a gas/foul smell and carbon deposits coming from the exhaust.
I pulled and checked the VTC solenoids by connecting them to the battery. They click and behave similar to the new one.
With a mechanical gauge, the pressure reads 50 psi at 2000 rpms. I've read in the Ford specs and Haynes that it should be at 75 at 2k rpms. It idles at less than 10 psi after warming up, but 50-60 or so at cold start.
I had it towed to my place, and I'm in the process of replacing the oil pump with a Melling 10340 now. One question that I have about the Melling is that it came with a 60 psi relief valve spring and an 80 psi relief valve spring. The instructions that came with the pump say that 60 meets that stock specs on the 4.6. I called Melling and the tech said to use the 80.
Any advice/help would be much appreciated?
