Guys,

I have a 2006 4.6 (200k) that has an odd problem recently.

Runs fine when started from cold start, but when it is shutdown and a hot restart is tried, it has serious issues such as misfire and stumbling.

If we let it cool down again, the problem disappears.

Check engine is on, codes are P0171, P0174 and P0193.

Fuel rail pressure is 40 psi per OBD.

Recently changed original fuel filter hoping for a cheap fix.

Next check is to replace the FRPS.

Any suggestions from the group as to possible issues to check?

FYI, the EGR is disabled via tuner, has been for years with no issues.

JT

 

FRPS is the next place to go. Another possibility is leaky fuel injectors or possibly the FPDM. FPDM is subject to corrosion.

If the injectors are leaking, starting it with the gas to the floor shuts off the fuel and clears flooded cylinders.

Those lean codes can be caused by an aftermarket intake without custom retuning.