Not a BMW but... Engine running backwards w/ video

[e30jake]

So my dad is helping a friend with his 03 Chevy 1500. Was running by jumping the starter. Then this happened. The engine fan turns counterclockwise when the starter turns it. It actually starts at one point going the opposite direction. "Exhaust" starts coming out of the intake. Any ideas as to wtf is happening?

https://vimeo.com/143267484

Sent from iPhone

[Best_name_available]

Lol wat

[Exodus_2pt0]

I'm no Chevy expert, but that looks correct based on the fan blade design.

Check your fuel delivery, then spark, then timing.

Edit: slow frame rate makes it hard to tell... If it starts spinning backwards after fire, check your timing. The fact that it sputters gives the opinion that it is at least getting spark and fuel.

If your timing is too far advanced, it could be igniting well before the piston is at TDC, which will force it to reverse rotation, as well as wreak havoc on the internals.

[DER E30]

It actually starts at one point going the opposite direction. "Exhaust" starts coming out of the intake.

Where is the fuel getting into this engine? If exhaust is going back out the intake then fuel can't make its way into the cylinders...