Something wonky with battery and engine
Old engine went to crap after seizing up. Dropped a new 4.0 in it. Ran fine for a while then it started idling low. Then at some point it would alternate between starting up and running fine and then on to days when need to be given gas in order for it to start and sometimes gas was needed in order for it to run. If i let the RPMs drop it would just die. Looking at the gauges, when I'm actually giving it gas the battery gauge is over the middle mark a little bit. When I let it idle today the RPMs were around 350-425 and the battery gauge would read a higher charge, then back to the mid point, and it would keep switching back and forth. The RPMs would also go up and down. Then I gave it a little gas and just let off a couple times and then after about the third time it just died. I don't know if its the alternator not charging or if the battery is going to crap. Any thoughts? I'm located far from an auto parts store so I don't want to have to drive out there just for it to be neither. Wanting second opinions. Could it be a bad ground? If I find out its a bad alternator, what is an option for a higher amp out put alternator that is a direct bolt up? I think i remember it being from an 04 Durango with a 5.7L. I could be wrong.