cylinder misfire

[frontline]

okay I have a 420a engine. cylinder 3 is not firing. symptoms, ruff idle no power, smell unburnt fumes from exhaust. codes p0303 wich is cylinder 3 misfire, p0455 is evaporation emission control leak, po442 small evap leak. I have looked all over for a vacuum leak cant find one, I changed plugs wires, checked compression, it was good on all cylinders. What could it be?

Please help!

 

[stars]

The coil fires thru the wire and into the plug. Take the spark plug out and hook it onto the spark plug. Let the spark plug rest on some kind of metal contact. Crank up the car and watch and see if the plug is firing. If no fire then check the coil. If coil is o.k. then take it to a shop and have them check which sensor it is. Evap leak code was set when you took off the gas cap and fueled the vehicle while it was running. And the other code was set because it seen a loss of pressure inside the tank which occured as you were re-fueling the car while it was running. It's trying to pressurize the system and it cannot because you have the cap-off.

 

[DSMOCTANE]

First steps I would take: -1. Replace fuel cap 2. Replace spark plugs & Spark Plug Wires. (Good start) If problem persists then check/replace coil pack!

 

[frontline]

Thanks for the response. I didn't fuel the gas while running but the vacuum line that goes to the cruise control had come undone and was sucking air, I put it back on but still have vacuum leak code. I have ordered new coil pack also getting new injectors probably needed a tune up anyways. Ill let you guys know if that fixes the problem.

 

[stars]

Yes a vacuum line coming off could have set that code as well, but normally I see those codes because of a faulty fuel cap, or like I mentioned fueled while it is running.
Check all those hoses even all the way back to the tank just to make sure. I don't like evap codes because they are too generic when they get set off and detected by ecu, it is another useless part installed just for passing emissions tests and being in compliance with fuel economy standards.

They could have done something different in their computer code that makes it less sensitive to set a evap code to begin with imo. Yes, a good tune up would not hurt because your not wasting money and if it fixes your problem you can send me the rest of the money you have saved =).

 

[stars]

Did that coil fix your problem?