Nissan sd22 diesel won't increase rpm when in gear

[skipperpete]

Originally Posted by Sandydog

No, have not! Engine only has 375 hours, but it is a 1982. I replaced all filters, both lift pump and mechanical pump, checked all cables, checked fuel tank pickup, bleed carefully. Starts and develops full rpm in neutral. Zero increase in rpm when in gear. Boat will move forward and reverse in idle rpm. No smoke. Good exhaust and water flor.

What type of injector pump does it have , the in line type or the rotary distributor type, this is a significant factor in solving your perplexing mystery. Each of the 3 types of injector pump can cause these symptoms but all 3 do it in different ways. The old inline pump is the easiest to troubleshoot and the rotary DPA with mechanical governor is next easiest but the Bosch VE is a tricky one.
Whatever pump you have, closely inspect the throttle lever and the nut that secures it because this really sounds like a rounded off connection between the throttle arm and the fuel control shaft it's supposed to rotate. Even consider undoing the nut or attaching fastener and inspecting the shaft where it goes into the pump.
Good luck.

[Sandydog]

Thanks for the ideas! It is a Kiki Bosch IP. On the exterior of the pump all looks OK. I guess I am going to have to open it up.

[Sandydog]

Well, I solved the problem. The fuel cutoff lever must be in FULL on position. If you have a solenoid like me, adjust it so it pushes the lever open 100 percent. Interestingly, the gine will not develop full rpm under load
unless the fuel cutoff is open 100 percent.

[sailormed]

Congratulations. Good job, you must be relieved.
You can be proud of yourself.
Was a hell of a conundrum.

[Sandydog]

Well, I just wanted to post it in case anybody has a similar problem.

[sailormed]

How did you found it? Desperate trials of everything?

[Uncle Bob]

Originally Posted by Sandydog

Well, I solved the problem. The fuel cutoff lever must be in FULL on position. If you have a solenoid like me, adjust it so it pushes the lever open 100 percent. Interestingly, the gine will not develop full rpm under load
unless the fuel cutoff is open 100 percent.

Thanks for letting us know the result.

[Sandydog]

Yes,you are right, desperate trials. First I replaces every fuel filter. Then the old electric lift pump. No joy. Then I replaces the old engine mounted fuel pump. No joy. Then I blew out the pickup tube. Nope. Then I replaced the fuel cutoff solenoid. Nope.Then I took apart the governor unit. All looked good, no broken or loose springs.

Ha, when I put the governor back together I noticed the new solenoid push rod was not adjusted properly so that the fuel lever opened the lever 100%. Made the adjustment---JOY!

So, bottom line, the original old solenoid was bad. My installation of the new one did not include the proper adjustment.

Still, a satisfying ending!