(ASKING FOR MY GIRLFRIEND'S DAD)

I was with my girlfriend's family last night and we had to move our Durangos around (Suprisingly, my gf's dad owns a Durango, mine is just a 2002 RT) and his turned over real slow, it had to try so hard to turn over. I asked if it's always done that, and he says ever since he got it.

He says he's replaced the starter and battery, which were my first two instincts to what was wrong. Would the alternator do this? I forgot to mention this. I know saying it might be his Fuel pump or something to do with fuel is 100% wrong, but I guess it might also be a possibility since a bad fuel pump will prevent the car from starting or running, but his just barely turns over.

I have no idea if he's looked into the alternator or not, I never asked, it was kind of just a casual conversation. I will have to ask, he's not a car guy so he probably doesn't even know what that is.

If I find more info, I will update this topic, thanks everyone!

 

be more specific about turned 'over slowly' did it crank for a long time before starting, or did it feel more like the starter wasnt spinning fast enough?

if it cranked for a long time then id suggest the fuel line check valve is bad (unfortunately its part of the fuel pump).

If it didnt seem to be spinning fast enough you could have some internal corrosion in the wires feeding the starter which would reduce the current reaching the starter, less current equals slower spinning.

 

It cranks over slowly. I will have to suggest the fuel pump and the fuel line check valve, it'd be good if I had a voltage meter to see if any voltage is getting to the starter/alternator just in case, just don't have one.

 

If a fuel issue, it would crank normally (starter motor spin speed), just might not actually start (run) quickly, would have long crank time. If the starter motor spin speed is slow, I'd look at all the electrical between the battery and the flexplate. You said you already did that, but look deeper.

 

disable the ignition or fuel pump to prevent the engine from starting..then measure the battery amperage draw when cranking.
normal draw for a gas engine is approx 25 amps per cylinder so 200 amps. over this and you got an issue.

anything that drops the available voltage will increase the amp draw required to start the engine...so do voltage drops of the battery cables to the start motor. possible items....Worn starter motor brushes, frayed braided cable from the starter solenoid to the starter motor. mechanical issues...tight engine was it rebuilt?