So I got in my truck this morning and it felt like crap. It is running very rought and misfiring a lot. It only does it in the low rpm's and if I put it in gear and sit at idle the rpm's drop and it dies. It's not the fuel filter, spark plugs, or O2 sensors. Does anyone have any ideas of what it could be. I'm pretty sure its electronics and it could be a sensor of some sort.

 

spark plug wire is grounded out on headers.

 

no it's not that, I checked the wires when I changed the plugs and they are fine. also I know that the whole left side of the motor is misfiring badly if that helps any.

 

Check the connector that feeds all the coils could have some moisture in it, or a wire has lost the insulation and grounding out. You might even have a vacuum leak.

 

Well guys im baffled. So I brought my truck in somewhere to get it checked out and they had it for a day and they tried a few different things then they changed the spark plugs and that cleared up the problem. What baffles me is that I changed the spark plugs on sunday myself hoping that would take care of it but it didnt and the plugs I put in were TR55's and the ones they put in were some generic brand so that confuses me. Also my father thinks that I just had a bad tank of gas because I filled it up on the same day this stuff started happening but if it was a bad tank of gas then how come one side of my motor was misfiring a lot more than the other. All 8 cylinders were misfiring but the left side was misfiring a lot more than the other side and if it was a bad tank of gas then wouldnt all cylinders be misfiring the same amount. Any thoughts would be appreciated.

 

Not trying to be a smart a$$ but did you put the wires back in the correct firing order? If the guy changed the plugs and put the wires back on correctly that would clear it up.

Dock

 

There's no way to mess up the wires on a 3rd gen V8 - each cylinder has it's own coil on the valve cover, and the wires are not long enough to reach a wrong plug. It would take a lot of intentional effort to put the plug wires back in the wrong place. It is possible though that the wires were not seated completely. Did you listen/feel for two light clicks when you plugged the wires back in?

 

Yes I put the wires on the right plugs and I made sure the wires went onto the plugs all of the way. I had one friend tell me that he thinks its something electrical probably something with the coils. I have another friend that thinks its fuel related maybe my fuel pump is going bad.