Mechanics

F150 4.2 ROUGH IDLE

2000 Ford F-150 • 6 cylinder 2WD • 98,000 miles

2000 ford f150. 4.2 liter, idles rough, remove coil wires, no difference in performance, checked OHMS across secondary resistance, read at 13.5k specs say it should be withing 6.5 ohms to 11.5 ohms., The primary resistance should be at 0.3 to 1.0 ohms, i'm at 0.8 ohms from the pos to all three negs, on the primary, any further ideas, compression was my next step.? I did a heat test on the exhaust manifold, 3 of my pistons were at 220degressF. Other 3 were at 550degreesF at the exhaust manifold, ideas?
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Pearlhickory
April 18, 2011.



http://www.2carpros.com/articles/engine-misfires-or-runs-rough

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

Note: If it doesn't apply disregard it

Rasmataz
Apr 18, 2011.
I have a 2000 ford f 150 it is running rough and cutting out and back firing changed coil still the same sparks from plug wirers when sprayed with water

Tiny
Cbman
Jun 21, 2012.