Have a 2001 dodge ram quad 5.9 engine code reader says number 6 cyliner misfire.Engine runs rough and back fires till it warms up .When warm doesnt backfire but still runs rough .

You'll have to look up the actual procedure to test the coil for code 351. The code means the computer is not able to fire the coil on demand which could be caused by several things, including a faulty computer. It could also be a problem with the wiring between the coil and the computer.

Hi Brian, I'm glad to help! First, when the engine shuts down you need to know if its loosing FUEL or if its NOT FIRING. This will send you in the right direction of diagnosing the problem, BECAUSE: It could be anything from a Shut-Down-Relay, a Bad Fuel Pump, a Engine Control Module, a Crank or Cam Sensor to various other things. Hope this helps and have an awesome day Brian.

May be a leaking or bad injector, Misfiring fm coil

Hi

The engine temperature sensor is bad. If so, the ECU assumes the engine is warm and it leans out the mixture, but you need a richer mix when cold, so it will run lousy till it actually gets warm.Check your coolant temp sensor. It may be defective and telling the computer that the engine is already warm. The computer is supposed to add extra fuel when cold to "choke" the engine until it reaches operating temp. If the sensor is reading incorrectly the computer may think its warm and not add the extra fuel to keep it running smoothly. Also check the two ground wires connected right next to the thermostat housing for loose or corroded connections. A bad ground here can also lead to running problems. If the sensors test ok have the timing checked.

Pull your diagnostic codes. The codes will tell if the sensor is not right.

Please get back to us if you have further query or else please accept this "particular" solution.

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Without your actual trouble code, I am assuming that you are have a misfire on cylinder # 5. The computer cannot really tell what is causing the misfire only that cyl 5 is not putting out full power. If it misfires when cold then smooths out as it warms up, I would say it is probably an injector that is sticky, as it warms up it starts working properly.

this is probably a o2 sensor

make sure the firing order is correctly. going clockwise on the cap it should go 1-6-5-4-3-2 and the cylinders are numbered as follows: passenger side from front to back is 1-3-5 and driver side front to back is 2-4-6

If the engine seems to run fine over 1450 RPM maybe there is a vacuum hose leaking or EGR valve is slightly stuck open. Any help from the OBD II trouble codes? Or is there simply no MIL and no stored information in the OBD II computer read at the local parts store through the connector by the drivers knee?

1.Start by changing plugs and wires. 2.Check for vacuum leaks. With the engine running, wigglr every hose you can see, to make sure nothing is loose or cracked. 3.Change fuel filter. 4.Check timing. 5.Check air control valve. 6.Check idle control sensor.

Here you go:
5.2L and 5.9L engines Firing order: 1–8–4–3–6–5–7–2 Distributor rotation: Clockwise

Diagram link below:

http://www.chiltonlibrary.com/content/images/7924/images/79243g14.gif

Best of luck!
Greg