Diesel Injector Pump Replacement - Crank Pulley won't rotate

[Southcott]

Hi Everyone - Have a bit of a problem here. I stripped down the top-end of the 1994 GMC Sierra C2500 with a 6.5L Turbo, and after aligning and installing the fuel injector pump, and the first bolt to the pump gear through the oil neck hole, my serpentine pulley won't allow me to rotate the engine to install the other two bolts. Any help/advice will be appreciated.

A few notes:

1) I performed the rotating of the engine when I disassembled initially, and I didn't have an issue.
2) The serpentine pulley will rotate back and forth about a quarter of an inch, but won't do anything else. I have a breaker bar set up on a ratchet wrench, which broke my wrench when attempting to rotate the pulley... seems caught up on something.
3) I did not drop any washers or items into the front of the engine during the replacement. After removing the pump I plugged the holes with a rag and vacuumed the dirt and debris and then wiped off the top of the engine with engine de-greaser. You can't eat off of it, but I made sure it was clean.
4) I made sure to line up the pump in the same spot (using a paint marker to mark the spot) and I also lined up the pin on the new and old pump without moving it on the old pump before installing the new one.

[Yukon6.2]

Have you pulled the glow plugs?

[DmaxMaverick]

Have you pulled the glow plugs?

Was thinking the same. Possibly hydro-locked cylinder(s).

[High Toned SOB]

Are you sure the 1/4” movement isnt a worn out pulley letting you move 1/4” of slop?
Then when you are actually trying to crank the engine over your just not pulling hard enough?
You have a rachet wrench on one of the 4 smaller bolts, i have broke tons of rachet wrenches using “more leverage” lol.


A 1/4” turn on a good bottom pulley is not even enough to turn the IP hardley at all. That is just taking the slack out of the chain/geartrain.

It makes a clank noise when it stops/hits right? Take that wore out pulley off the bottom and try to turn it with the balancer bolt.