2002 4.0 explorer problem after engine swap

[WarriorDriver]

old motor blew a rod out the side of the block, put a new longblock in, used the old intake and everything else, it keeps throwing p0171 and p0174 codes, Ive changed pcv sensor, and the other sensor on the front of that valve cover, changed intake gaskets, changes vacuum hoses, I just cant find the problem.. It had zero codes before.

help?

 

[2000StreetRod]

replacement engine last ran?

Do you know how long it has been since your replacement engine ran before you installed it? If it was a long time maybe the injectors are clogged. You might try adding a bottle of Techron to the fuel tank.

Have you checked the fuel pressure? Maybe it is low.

You might try cleaning the MAF sensor with MAF sensor aerosol. Maybe the sensor got contaminated.

 

[WarriorDriver]

not sure how long since, have no way to check fuel pressure, it was fine before the engine swap. Ill try the maf cleaning, it also was fine before.

Thanks

 

[boominXplorer]

Check and make sure none of your intake manifold grommets are split. If so the intake is not holding down tight enough and it is leaking air between the head and the intake manifold. Its a common issue for 02+ trucks with age.

 

[WarriorDriver]

Check and make sure none of your intake manifold grommets are split. If so the intake is not holding down tight enough and it is leaking air between the head and the intake manifold. Its a common issue for 02+ trucks with age.

The intake grommets on the bolts are all new, the intake O rings were all new.