Hi, i hope that i can get some help from anyone in this forum, i havin problems whit my Dodge Dakota 2004 6cil 3.7 lts, the thing is that i have a misfire at idle and the p0300 code comes on, the truck when its Cold in the morning and you star it to warm it up for 5min and then drive wont do any problems, then when its warm or hot at its normal tempeture driving range and you stop the engine for more then 5 min and then you start the engine again and drive of the problem comes on as the truck wont take off freely and feels like is choking, (the check engine light stars flashing and then stays on) if you stop then the engine shakes really bad,but then you step on the throttle all the way to take off again and the engine stars to pass by that problem and then takes of freely and as long as you drive it around and dont stop the engine it wont do that problem anymore, no matter what speed range you are at it wont causes any problem , another thing is that if you take of after being stoped for more then 5 min and step on the throttle and dont stop or reduce speed to idle seems to by pass the problem and doesnt do it until you stop the engine again for more then 5 min, the main thing its that it only does this problem when engine its warm you star the engine and idle when the problem comes and you by pass it by stepping on the throttle and drive off it wont come again even of you reduce speed to idle, And this misfire never comes at hi speeds or medium speeds or at a any speed at all... Only at idle... Any way heres what i have done so far:

1.-Spark plugs changed and checked
2.-IAC valve changed
3.-Fuel pump changed whit filter regulator
4.-Solenoid purge valve changed
5.-TPS changed
6.-PCV valve changed
7.-Manifold intake changed and gaskets of course
8.-checked for vacumm leaks spraying carbuclean around and idle didnt change
9.-Air filter new
10.- MAF sensor new( just in case)
11.-Fuel injectors clean and tested
12.-Fuel rail clean
13.-Air hoses changed to avoid vacumm leaks
14.-Battery test whent good
15.-Crankshaft possitioning sensor changed
16.- ignition coils seems to spark good
17.- compression test good
18.- theres no wet spark plugs when you take it off not for gasoline or oil
19.- Cat converter have been removed also

Thats about all i remember jeje!!
I just hope that anyone coils help me... Thanks a lot for your time!!!

 

Did you check your plug wires? Take the truck out on a dark night, raise the hood, and look for sparks along the plug wires. If you see sparks flying, you've found the cause of your misfire. It's a free way to check the wires. Moisture on them will promote more problems.

Otherwise you need to troubleshoot rather than just replace parts.

I just put on my second crankshaft position sensor in my 3.9, and the sensors that did not come from Chrysler do not hold up well. They are slightly shorter and eventually that gap is too much.

That's all I know to offer you. Others will no doubt add their ideas.

Good luck and let us know what you find out.

 

What plugs are you running?
What is the fuel pressure?
Disconnect the battery and pull the connector on the PCM. Make sure they are clean and dry. If you find oil you have another problem.
Why did you change the crank position sensor? Was it due to a code?
Check out the cam position sensor - use only OEM.