Soo here it goes, i have this 2004 dodge ram with the 5.7 hemi that has a terrible miss fire that i cant track down, so anyways was cruising that down road all ***** nilly everything is great! Till all of a sudden started misfiring like crazy but still had enough power to continue my journey home, anyways i get it home it stalls, but could get it running again if i Jammed my foot to floor, runs like its sucking it water like when that air box gets water in it from going too deep in the mudbogs know what im saying, anywho just changed all 16 plugs, cleaned throttle body, checked fuel pressure, checked wiring, disconnected the battery a few times, and nothing still tuns terrible, best part is no check engine light either, so im currently stuck and not sure where else to look, its not smoking its not running rich its not backfiring im at a loss any help to point me in the right direction would be greatly appreciated

 

Start the truck and let it idle, then one by one disconnect the harness connector from each coil, listening and watching for any change in the engines performance. If you disconnect a coil and you don't see or hear a change in the engine, you found a bad coil.

That's the first and simplest thing you can do.

 

great idea i did forget to mention truck does not idle

 

Do you have a scan tool? Are you able to view the fuel trims? They've had some issues blowing apart the lower intake manifold and causing massive vacuum leaks.

Don't disconnect the battery anymore tho, every time you do you waste the freeze frame data

 

kinda not really, working on getting a matco scanner for personal use, might be able to borrow my buddies snap-on scanner in the meantime, i will keep you updated

 

So brought home the older snap-on scanner, would not tell me fuel trims, and nothing showed up on the misfire counter, so i could not figure out witch cylinder is missing, i read into the scanner and apparently it wont pick up misfires on the counter if severe, going to try a different scanner

 

So i think im getting closer im pretty sure its over fuelling, took out a couple of the plugs and they are black and soaked in gas, things are literally brand new, whats the best way to check these injectors and or things i can check and yeah still no CEL and compression is 150 all 8 cylinders

 

Advance Auto and Autozone will let you use a scanner if one is nearby. Call them first.

 

Problem found! Found a broken exhaust spring, witch i am surprised it past a compression test

 

Replace all the springs with hemi 6.1 exhaust springs.