I have a 03 dodge ram 2500 Laramie with the 5.7 in it. where to begin well 2 years ago I had 3 valves springs go flat on me I took it to a garage the fixed it and put new plugs and coil packs on . well about a week later the engine light came on and he tuck started to run really bad. well to make a long story short and a lot more engine lights I have replaced all the fuel injectors the fuel rail both o2 sen the spark plugs again . the truck is still running bad and the new code is random spark plug miss fire.

can some one help me thanks rich

 

Have you gone back to the "garage" that worked on it?

 

What kind of spark plugs did you use? I hope you put copper plug in. Assuming you are using copper plugs and with all the changes you have done, I would think an engine mechanical test is needed. What kind of testing was done before changing the fuel injectors and fuel rails. Are you sure the wiring harness and PCM were good.

 

To the OP, All the parts that have been changed, was there a reason all the parts were changed, or have they been changed shooting in the dark? Generally, if there are problems, DTC codes are set in the ecm computer. The codes are the starting point for the diagnostics. If I had to guess, my first would be bad plug wires, but I don't know if they were changed with the coil packs. Could also be caused by bad grounding throughout the truck. See if you can pull the codes with a scanner or the key trick in the odometer and bring back here.

 

Is it terrible that when I read the title of this post I thought, ok, replace the pcm and motor then.. haha.. just kidding man.

Agree with gonefishin, post the actual codes and we can go from there. I believe there are multiple codes that come up with random spark plug misfire, or at least there are likely to be more than one if you have that one too.

 

I would love to but it happened when I was on vacation and that is a 4 hr ride from where I live. but I did call then and asked them what they thought and they have no idea.

 

I don't have the code with me right now but I get them for you and post them. for the plugs im using double platinum that what dealer told me to use .as for replacing the injectors I was getting codes for cylinder running to lean to running to rich to not working at all so for each time I get the code I would first switch it with a deferent cylinder and the code would follow and after the third one I broke the rail . I check the grounds and wires and let you know.

thank you for all the help

 

Those platinum plugs need to come out and the correct plugs installed. I used NGK 5306s in both my Hemis.

Post up the codes for sure.

 

Yank the double platinums and install the OEM copper champions. This is a fairly inexpensive way to eliminate one potential problem, then try the higher end stuff in 30K when its time to change out the plugs again.