Ford F-150 XL extended cab side door 8 foot long bed 2 wheel drive 6 cylinder 4.2.
Fix slipped timing and it will run and drive. Work truck with livestock body damage. It will run, drive, good power, doesn't smoke. Was Used daily. Needs power steering hose and battery. Has new ignition switch and new starter. I ran out of money. Before ignition switch and starter it was running/driving fine. After mechanic put in starter, it was backfiring in intake trying to start. . Reset timing to run fine- Timing slipped. Here's what the internet says.
An intake backfire during startup on a Ford 4.2L V6 usually means the air-fuel mixture is igniting while the intake valve is still open. This is primarily caused by spark timing that is off. A very common mistake on this engine is misrouting the spark plug wires to the Ford Coil Pack. Because of the coil design, wires on the passenger side are arranged as 4-6-5 (not sequentially), and mixing them up will send spark at the wrong time, firing into an open intake.
I wouldn't think the mechanic messed with ignition wires, but maybe he messed it up trying to get more money. I've dropped price to $1,200