I have a 2003 t & c 3.8 litre, fwd, automatic tranny that misfires at idle. Changed the plugs, wires, fuel filter, dumped fuel system cleaner in it. Code that came up is p0301. Took it to chrysler dealership and they reprogramed the computer with new updates. They see this quite frequently. Says it has something to do with the new wires not being chrysler oe(resitance not up to par). After all that it still does the same thing. Checked for vacuum leaks. It really idles bad when put into gear, almost dies. Any suggestions?
I checked IATN. Haven't found any known common failure pattern on cylinder 1. But.1 guy had a similar P0301 code. It was the plug. Guess u can swap the plug and see if the misfire goes to other cyl. Educated guess. Other than that.1 cylinder misfire. Can't be that hard to figure out. Either fuel, cam, ignition timing, good sound engine mechanical. Or fuel ctrl. Any L1 mechanic should be able to nail it down.
August, 23, 2007 AT 4:05 PM
Star parts Tech tip. Closely inspect the wire take-out to the fuel rail in-line connector onthe powertrain harness. The harness may have been moved during previous service actions. The wire take out is clipped to the engine driver's side spark plug cable spreader bracket. A misrouted harness could make contact in the area and induce a misfire and /or MIL illumination. Affected area can occur 1" above the clip. Look for any signs of damage and bend the bracket outward(toward the driver's side) approx. 1".
October, 27, 2007 AT 10:55 PM
Changed the #1 injector, inspected all wiring, swaped plug and wires, inspected top intake manifold gaskets, and changed the pcv valve and still idles rough. Any other suggestions would be great.
November, 1, 2007 AT 11:42 AM
Found out what the problem is. Defective cam shaft from the factory. Apparently it had the smooth finish warn away and at idle it was very erradic. Talked to the original owner of the vehicle. Did everythng we did to it. Funny thing is it was a chrysler dealership and at the time it was under warranty 7yr/70,000 but they could not diagnosis it. Complete incompitense and they will not stand behind it now. But good news, the dealership that I bought it from is replacing the motor for free. Seems it cost less to do this than replace the shaft, clean out the filings of metal, replace pumps, ect. Got very lucky with this dealership. It's nice to know someone that stands behind their product. Oh, and the original owner will know about how bad he was treated and I bet that chrysler dealership looses a good customer.