'01 4.0 SOHC - Runs rough & dies - No Codes

[cal74]

Just picked up a '01 4.0 SOHC that sat for a couple years. Person I got it from was told it was a fuel pump, which he replaced and that didn't resolve his issues. Not sure what else he attempted.

Will run, not sure how many cylinders it's firing on but it's tough to get it to run and it will not idle.

It's from the rust belt, but overall in pretty good shape with about 95,xxx on the clock. I did see one vacuum line off below the throttle body, but that didn't make a difference. All other lines appear to be in good shape.

Today I took the intake manifold off, gaskets didn't look terrible and the new ones were a little loose so I ordered another set.

Fuel pressure at the shroeder valve appears good. Tester I rented had a bad gasket in-between the valve and the test valve, so it leaks down from there but two turns of the ignition is showing 40 psi, three turns will hit 60.

Plugs are good, wires are good, not positive on the coil pack?

What else should I be looking at? Dread the thought of pulling the motor.


Thanks

 

[cal74]

Anyone?

 

[DILLARD000]

Replace or at least clean the PCV valve on the rear of the left ValveCover.
Closely inspect the PCV hoses\tubes for cracks\leaks; the PCV "L" hose just to the right of the Throttle is notorious for cracks.
Make sure the right ValveCover vacuum tube to the AirIntake accordian tube (between the MAFS & ThrottleBody) is intact & connected proper.
Make sure the MAFS~ThrottleBody accordian rubber air tube is not rotted\leaky.
Remove\clean\re-seal the ThrottleBody.
Replace or at least clean the MassAirFlowSensor & make sure the electrical connector & harness are in good shape.
Replace or at least clean the IntakeAirControlValve on top of the Manifold throat; this controls the ColdStart~WarmUp RPMs transition.
Make sure the IACV ORing\Seal\Gasket is good.
A bad ThrottlePositionSensor\TPS can cause hard starting\idling\shifting issues; check that signal.
The ExhaustGasRecirc\EGR valve & related DiffPressFlowElement\DPFE sensor could also be bad.
Scan & make note of the OBD2 TroubleCodes; you'll likely have several.
If spark plugs\wires\coil & O2 sensors are over 100k miles or FactoryOE, they need replacing.
Inspect for damaged\broken wiring\connectors\hoses.
If vehicle sat unused for months\years, mice\squirrels\chipmunks eat plastic\rubber & make nests, check the Air Filter+Box.
May want to install a fresh FuelFilter, on the left frame under the drivers side.
Install & try one thing at a time, so to differentiate what is a problem source\fix.
Good luck.