Hard to start 2001 Ford Explorer

[220richard]

My truck is hard to start (Easier to start on cold mornings) and sometimes wants to bog down when accelerating from a start. Idles fine:

Codes: Lean codes

2001 Ford Explorer V6 - 4.0L vin E 245ci - MFI GAS SOHC

Replaced:

MAF
Fuel pump and all parts of fuel tank
Fuel filter
MAF
IAC
EGR
TPS
O2 sensors

Might be forgetting some new parts...

Tride to find vacume leak. Does not appear to have one.

Checked PCV valve - fine

Replaced MAF, IAC, TPS again

I am beginning to wonder if the after market fuel pump just isn't putting out enough pressure?

What if the computer was reset?

Thanks for any help in advance.

Today I am adding sea foam to the gas tank and cleaning the throttle body again.

Oh, one more thing. If there is some throttle cleaner left in the throttle body it will fire right up then die.

Respectfully,

220Richard

 

[koda2000]

if you have lean codes, you have a vacuum leak somewhere. very likely intake gasket/o-rings, especially common on 4.0L SOHC engine, but a vac leak anywhere will cause the same problem, even the brake booster.

 

[220richard]

Thanks. I will look again.

 

[220richard]

The new fuel pump had a bad fuel pressure regulator. Replaced the pump and all is well (operating pressure 70 psi). Not O'Reilly Autos replacement pump's fuel level sending unit would not fit through the tank's hole so don't throw out original in case you need parts.