I am working on a 2000 jeep cherokee 4x4. It came in the shop with a 8 inch crack in the cylinder head with a blown head gasket, but was running, so I recommended engine replacement. The customer provided a re-manufactured engine. I replaced all parts from old engine.
I have removed timing cover and checked timing marks I have removed transmission and checked the flywheel. I have replaced crank sensor and coil pack. I have set the oil pump drive gear the exact way it came out of old engine also tried turning it several ways to see if it would start. Still backfiring thought the intake and exhaust and wont start?
Sounds like you need to set the valve and ignition timing correctly-start here
November, 20, 2011 AT 6:54 PM
The PCM set ignition timing with the crank and cam sensor the shaft for the cam sensor drives the oil pump like a distributor like a ford the cam sensor is reading and crank is reading sqare wave patterns good at the pcm could the cam be a higher duration than its suppose to when they rebuilt the motor?