Cleaning out cruddy injector bores

[TheRadBaron]

I’m changing the injectors on my ‘94 factory turbo 7.3 and the injector bores in the heads are pretty cruddy inside. I’d like to clean them out but I guess that knocking a bunch of crud into the prechambers isn’t ideal.
I figure I’ll use a shop vac to vacuum them out. The Haynes shop manual I have for these engines says to blow them out with compressed air.
Is there any other tricks or techniques for cleaning the bores?

ETA: Also, the drivers side injector tips all look pretty clean and dry. The passenger side are all wet and cruddy. Is this an indicator of a problem? It seems odd to me but the truck runs perfectly. I’m just changing the injectors because they have an unknown history and I have a bunch of other things apart so it was a good time to change them.

 

[FrozenMerc]

It adds a bit of time to the process, but bring each cylinder up to TDC before you start cleaning that injector bore. With the piston at the top, it will minimize the amount of schmoo that falls into or collects in the cylinder.

 

[Clb]

Snapon pn.
Mb73a

 

[gandalf]

For those of us with a 12 gauge shotgun, a 12 gauge bore brush is just the right size. Then I would suggest either vacuuming or blowing out anything knocked loose.

 

[TheRadBaron]

Sounds good. Thanks for the tips.

 

[nelstomlinson]

Would you want to be at the beginning of the compression stroke before you clean, then crank it to the top to blow crud out of the prechamber?

 

[onetonjohn]

I would try to find a hex plug that fits the hole and then use a brush and compressed air. Maybe compressed air with injector installed, but backed out a bit. For sure, I woudn't want anything getting in the engine.
That said I'm not an engine builder.

 

[KyleWest]

My understanding is that the glow plugs can be removed and compressed air blown through that hole to clear the entire thing out

 

[Clb]

For those of us with a 12 gauge shotgun, a 12 gauge bore brush is just the right size. Then I would suggest either vacuuming or blowing out anything knocked loose.

Yep, however it will miss the pintle bore, ( look closer at the small end of the one I posted.

 

[HammerDown]

Here's a thought ... using an air compressor with a good sealing tip blowing air into the GP hole while using the proper injector bore brush cleaner... this way as your scrubbing the 'hole' the debris is being forced 'out' the injector hole. Oh, and wear safety glasses and make sure the intake is covered.

 

[Clb]

Valves closed also

 

[IDIBRONCO]

Valves closed also

That's easy enough. Just loosen your rocker arm bolts.

 

[TheRadBaron]

I like the idea of having the valves closed and blowing compressed air into the GP bore while scrubbing the injector bore.
Rather than taking off the valve covers and loosening the rocker arms wouldn’t it be feasible to rotate the engine and scrub the bores in sequence with the firing order?
I believe the engine fires a cylinder every 90 degrees of crank rotation. Is this correct?
If so, I’m thinking that I could set #1 at TDC on the compression stroke, scrub/blow out the injector bore, rotate the engine 90 degrees, scrub the next cylinder in the firing order’s bore, repeat.
Does this make sense?