I have seen on a number of posts where it's always stated NOT to move the pump while the engine is running. No, I"m not going that route, just wondering why? Does something break?

 

yes! warning! you can completely destroy the fuel injection pump by attempting to turn it while the engine is running.always insure the engine is off while making adjustments.you will break the ip internals if you attempt to make adjustments while the engine is running.

 

I suspect the real risk is more of damaging the lines than anything, if it's loose. The pump can only turn a good 10 degrees of timing in it's slots, so it can't go very far.
I've seen a few videos where the owner rigged up a turn-buckle as an adjustment for timing; then adjusted on-the-fly with the engine running.
I'd be really careful, though.
Personally, I've just moved it a bit, ran it, stopped, etc. It's not a hard/slow process if you trigger the starter from the front of the engine and pull the FSS wire to shut the engine off.

 

warning.
i have to correct you.the real risk is in fact severe internal ip damage rendering the ip useless/parts. im not making this stuff up.please heed my warning.it could save you several hundreds.

 

First, think about what we're dealing with. The IP shaft is riding in a bearing/bushing. Circular rotation will, by definition, not hurt it. Side loading might... But we're already putting significant strain on it just pumping fuel through it(Have you ever run a pump on a test bench by hand? It's a lot of work turning that wheel)
The gears themselves have a little play, which should take up any slop in how you position the IP relative to the gear cover(remember, there is a cylinder at the end of the IP which slips into a round hole in the gear cover, which prevents the IP from moving "sideways" more than a couple of thousanths) -- and any position you can get to with the engine running you can get to with the engine off!
Just think logically here -- don't repeat FUD.

 

I agree that I've read many posts and warnings about NOT doing it. And I agree that one shouldn't do it.

From personal experience, I didn't know any better(6-7 years ago) and goofed around with my first pump with the engine running 4-5 times. I thought it was more like a distributor on a gasser than some insanely delicate, ultra-touchy, super-tight-tolerance diesel timing device.

And to be honest I don't think I messed it up any worse than it was already. Before I messed with the timing I put new injectors in, but with the old pump... So that killed the pump. It was leaking fuel out the housing and the forums and Seattle Injector all said there's nothing you can do but rebuild it.
So nothing broke or anything but I agree that if you just bump the solenoid and use the FSS to kill it the adjustments take practically as much time as getting all your timing gear out.

 

I always figured it was because of the torque being put into the pump- as soon as those bolts are loose, it's going to slam as far as it can to the retarded side and be very hard to hold back.

Sent from my Brigadier using IB AutoGroup

 

I'm going to have to agree with this answer. It is the only logical reason.
With the vibration these engines put out it would be near impossible to fine tune with the engine running without a solid mechanical connection like the turnbuckle mentioned above.

 

Thanks to everybody for the answers. I also asked they guy that rented me the "TACH-AN-TIME" meter and he said the same thing including the preasures involved with the pump. With all the posts that said "DON'T" I wasn't about to try it.

 

the turnbuckle was holding the rpm cuz he needed two hands to play with his light system. as you must check timing with engine a 2000 rpm. exactly as at a idle the timing is advanced some 12 degrees from what it is at 2000rpm. 1 degree at the pump is two at the crank.

 

Along with the risks of damage listed above, you probably don't want to be working a few inches above a radiator fan turning at 2000 RPM. I sure don't.

 

So remove it?
The engine will run just fine without the fan, at least for a while(it takes lots of time to heat up with no load on the engine, from the ~180 you should be at to the 'time to shut down' point of 230.. and really, you'll only be running the engine for a minute or two.

That being said, I recommend leaving the guard on it if you leave the fan on... it's hard to see that fan when it's spinning and when you accidentally touch the fan blade as it's spinning... it hurts. A lot.

 

I'm out. Not going there.

 

Wow....just wow.