CAT 3412 won't throttle up?

What throttle control do you have? Not running, key on, push the throttle to WOT, make sure the governor moves to WOT.

Had a boat with B+ issues with old mathers controls doing the same thing.

3412s did not have that fancy of a computer.
You still have not explained what rpm you are getting.
Nor what controls you have.

3412 or 3412E?

210 is way too high. What RPM were you running. Even 190 is a bit high depending on RPM. How about the gear temps?

That shouldnt prevent the engine from reving up. Does it just stay at idle? How about in neutral, will it rev up? Sound like a control issue

Ah, Kobelt controls. No experience there.
But I think I was close.
Please keep us up as I'd like to learn more about these fancy controllers.

Also, My past with 3412s with ZF clutches, a side line after the Sherwood pump goes off to cool an internal H/E.
It's a small hose (1/2"?). I have back flushed these with dock water. Some trash did come out.
The later 3412s I've been with had the fancy stacked plate H/Es, If your is the round monster, the end caps offer a good inspection option.
I think rather large rods that may be easy to clear if they have any restrictions.
You just may find one end cap full of trash that a chemical cleaning may not clear anyway (old impeller bits, plastic, sediment and grass goo).

I m familiar with the 3412Es not the ealier ones. The 3412Es have a gear cooler on the ZF. Typically the first symptom of an impeller issues was always the gear running 20 degrees warmer at idle speed. Go back at 1000 or higher and the gear temp would come back down.

The 3412Es have fuel cooler BEFORE the raw water pump. Anything making thru the strainers ends up trapped at the fuel cooler inlet. They need cleaning every once in a while. Not sure if this applies to the earlier 3412

How old are the impellers?

I d suggest you call southshore diesel. They really in miami but also cover Very reasonable and quality work. Marcello, the owner, has been doing my cat work for 10 years. He also surveyed the Lazzara I run (C32s). They just did impellers and service on ours. Good guy

Stay away from pantropic.

Other pump?
Other HE (heat Exchanger) for the ZF clutches. I remember internal in the ZF clutch.
Off of same main engine Sherwood (Shurfail) raw water pump.
You may have a power steering pump the size of a beer can somewhere.

I forget where the fuel cooler is. Think Pascal is on that if it's a multi tube Pack.

Heed Pascal comment; "Stay away from pantropic".
They have already bent over two of our customers.

Not coming up to RPM:
Could this be as simple as a fuel restriction in the supply side of things? Filters, Fuel line etc. I had a similar problem with a large Generator yrs. ago that after going through the motors mounted fuel supply systems we found our beautiful Aeroquip supply line full of algae from the day tank to the suction side of the Racor. Gen wouldn't turn more than 1000 RPM's till cleared .

That's good news. When you said "Kobelt" my mind automatically thought Pneumatic controls. Didn't know that they were a player in the electronic controls field.

I can not find Kobalt controls anywhere. Nothing on the web. Never operated such an gizmo.
We may have an auto spell check kicking in on somebody's pad or kbd.
Not knowing anything about them, I have operated Kobelt controls of many types. All were very fine.
Never worked on them at all.

Of course, please keep us up on the fix and suspect failure cause.

I hope you had a good time in Miami / K B.

Good grief, that sounds like a bit much for what should be a bullet proof system. Kolbelt pneumatic controls are pretty reliable as long as you take care of your compressed air system aboard and place a commercial dryer evaporator in line before the receiver. I'm beginning to come to Ralphs conclusions here of just give me a push pull Panish system. I priced out a two station electronic control system for a customer two yrs ago and was surprised by the cost. Between Z.F. Glendenning & one other I couldn't find anything south of $25,000 complete .