Rough run. Completely stumped!

[MxRacer855]

Hey everyone,
I recently replaced some lights in my cluster along with installing a tachometer. I did this while installing a new heater core. I'm almost positive everything went together as well as it could. When I was all done and put everything back together, the engine ran extremely rough like it was knocking in a few cylinders. It was 100% fine when I started this job and did absolutely NO work underneath the hood during the process. I did remove the Mopar Performance Orange ignition module on the firewall though to gain access to the heatercore fittings. The only thing I could think of regarding possible causes for my engine to seem like it's only firing on 4 or 5 cylinders was that I accidentally dropped that module and could have disrupted it. I purchased a new one and the problem remained the same.

I know this is a very generic symptom, but given the work that I did, any ideas from anyone who has dealt with something like this in the past? I'm pretty sure there isn't a vacuum leak either.

Thanks

-Jeff

[RECHRGD]

Well, if the only thing you touched was the module, that's where to look.  Be sure all the wiring is connected properly and tight.  Be sure ALL grounds are good.  Check the engine ground also.......

[MxRacer855]

Would you happen to know any grounds behind the cluster/dash that would directly effect the engine? It's really unusual how big the problem is for whatever I did. I need all new wiring for the car. It's just such a nightmare to dig in there and check everything. I would have never pulled the cluster in the first place if I had any idea this could be a possibility, haha.

[myk]

I would look back at the ECU; if it isn't grounded properly that can definitely cause driveability problems...

[Cooter]

Again, stock ECU= junk imo..

[Chryco Psycho]

disconnect the tach , it could be grounding the coil through the signal feed wire

[MxRacer855]

Hey guys, I fixed the problem. There was a loose wire going into the ECU harness. In addition to that, it just happened to be a coincidence that my flex plate screws came loose at the same time and were beginning to hit my transmission wall. I'm glad I caught that one before I had some serious damage! Thanks again.