first of all hi to all here. been awhile since i've been on here. after sitting engine cranks longer than it usually did before it starts. idles a little rough.engine light comes on after it been running about 30 sec to 1 min. after that seems to run fine.check codes po446 and p1633 always come up.if you let sit a bit with key on starts right up.replaced gas cap, checked evap lines, and changed filter no help.did notice with lines off evap solenoid key off or on i can blow through it. that doesn't sound right. can anyone enlighten me on that ? checked fuel pressure. key on jumps to 90psi then falls to 55psi and stays. turn off key and leaked off 10psi in 5 min.start engine while watching guage does the same as when key on except it falls to 30 to 35 psi and bounces between them. i think this is way low. can someone tell me correct pressure ? shut off engine and drops to 20 in 5 min. next i plugged line on test tee going to fuel rail and tested same results as key on. convinced fuel pump was bad since regulator and check is there. replaced pump 400.00 ouch. problem still there.any suggestions would be appreciated. sorry for the book

 

Welcome to FTE tunedbyear,

Try working on the P1633 first then the evap system.

We have a Taurus that would show evap codes, but I canʻt remember which

one. I ended up replacing the fuel cap which solved our issue.

Such a simple fix, go figure.

 

I have a 2006 Explorer, two months ago got the same two error messages. Also, the truck always started immediately, since getting the two faults, it now cranks for about 5 seconds before starting. What did you find with your truck?

Thanks,

Mike

 

Answering too late. Likely fuel pressure regulator/sensor. Pressure ought to be around 60 psi all the time. impish

 

Thanks for the reply, it will be a couple weeks before I can tear into it. I'll post when I can get some measurements.