I took my 02 dodge ram 1500, and dropped a 4.7 HO in in place of my stock 4.7. Now, maybe 500 miles later, I am misfiring on cylinders 3,5,7. I replaced the spark plugs when i switched the engine, and i also now have replaced the coil packs for those 3 cylinders, but to no avail.....Any ideas? I just want my truck back.

 

I would either do a compression check on each cylinder or pull the valve covers and check the rockers. Thats where I would start.

 

i appreciate it.

 

would it make a difference if its chaotic rather than regular?

 

Normally the rocker issues that people see and/or compression issues would make it run bad all the time. If this is intermittent then is sounds like you may have other issues. Did you have hard codes (CEL)? If so were they checked and what were they?

 

I took it to autozone and they hooked up the scanner, and it was the three misfire codes, one for each cylinder, and then a bunch of emissions stuff because of the unburned fuel.

 

Alright, well just an fyi i took it to the dealer today, they told me that its because the pcm for my truck was a 3rd gen with a 32tooth crank, and that the one for the jeep i took the engine out of had a 16 tooth, and i guess its just been slowly slipping out of timing, and so now its just running like ****.....HOORAY????? now i need to take the crank out...but yeah......anywho...figured id tell you guys. the part is called the tone (spellcheck) wheel.....