I have a 2007, XLT, with the 4.6l v8. Recently, I had to replace the intake manifold, and when doing so, replaced the fuel injectors, spark plugs, ignition coils and EGR. After this, the fuel pressure holds steady at 39-41 psi. There is now an occasional spike in fuel pressure, to in excess of 55psi. Have now replaced the fuel rail pressure sensor, and FPDM. The fuel pressure spike persists - particularly when the engine is at full temp, and has been running for 30 minutes or more. Died while driving last week, with no codes. Anyone have a similar issue? Any input would be appreciated.

 

Why was intake placed (symptoms)?

suggest trying to provide more detail about conditions/scenario when it dies?

does it immediately restart? If not, what needs to happen before it restarts?

When it dies, does it feel/act like fuel starvation (gradual) OR spark/ignition (sudden, like being shut off)?

 

Sorry - intake manifold was replaced for to leaking coolant, which was pooling in the spark plug wells, causing a misfire. When the engine died, it just shut off - almost like the computer killed it. Afterwards, it would not restart. As if there was no fuel. After letting it sit for 4 hours, it restarted, and ran like nothing had happened.
since that happened, when driven for a short period, once you shut the engine off, upon restart, it needs a few seconds to restart, as if it’s starved of fuel, or the fuel system is repriming.

 

what is fuel psi doing as it kills and while it will not restart?

if You carry starting fluid and can quickly remove intake tubing, be ready for it to fail and spray straight into TB and see if it fires. You have to be quick and be sure it is in still fail mode for this test to be valid.

in other words: isolate it you have a fuel delivery problem.