Fuel Pressure

2002 FORD EXPEDITION

135,000 MILES • V8 • 2WD • AUTOMATIC

AV_1965

MEMBER
2 POSTS

I've been trying to diagnose a slight miss in my parents' 02 Expedition, 4.6L. The repair manual I have says fuel pressure should be 50 psi (key on engine off and running). Does anybody have different specs? If so, what are they and what is your source? Thanks.
-Anthony-

Jul 13, 2011 at 11:24 PM

RASMATAZ

✓ASE Certified Mechanic
75,992 POSTS

Go to this link: https://www.2carpros.com/articles/engine-misfires-or-runs-rough

Image (Click to enlarge)

Professional Diagram for 2CarPros Members
Click here to log in and view diagram.

Jul 13, 2011 at 11:41 PM

AV_1965

MEMBER
2 POSTS

Thanks for the screenshot. I tend to trust Mitchell over Chiltons or Haines, anyway. I should mention that I'm getting roughly 35 psi KOEO and 30 KOER. Looks like I may have to look elsewhere for the source of the miss.

Jul 14, 2011 at 12:33 AM

RASMATAZ

✓ASE Certified Mechanic
75,992 POSTS

Could be one of the following:

1.Defective spark plugs
2.Inadequate spark/coil,defective spark plug wire.
3.Lack of compression
4.False air leakage.
5.Faulty fuel injectors.
6.Insufficient fuel pressure.
7.Contaminated fuel.
8.EGR valve that is leaking.
9.Oxygen sensors.
10.Throttle position sensor.
11.Manifold absolute pressure sensor
12.Mass Airflow Sensor
13.Idle air control valve

Jul 14, 2011 at 2:55 AM

Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.