My car sometime start weak and sometime it start strong! It got a new battery what could cause this problem? The car is a 2000 Dodge Durango 5.9 engine!
It is most likely a bad connection causing a voltage drop in the starter circuit. Most likely causes are where the cables connect to the battery and/ or the starter. You can use a voltmeter to perform a voltage drop test at each connection. Place the test leads across each connection while someone "cranks" the starter. If the the Volt meter shows any significant voltage, you have found your bad connection.