Nissan LD28M runs rough at low rpm

[DonGuy]

Hello,

I have a marine-configured LD28 in a 1986 albin 27 boat. An "LD28M". It starts well and runs nicely, except that below 1100rpm it runs very rough. No smoke. A lot of vibration from idle up to 1100. Smooths out above 1100rpm or so. Rough whether cold or warm. Has about 3300 hours.

I'm hoping someone may be able to point me in the right direction to fix this. Is there a common problem with the LD28 that will cause it to run rough at low rpm?

I'm going to have the injectors cleaned, refurbished, tested etc.

I'm wondering if I possibly have a problem with the pump. Yikes. The pump appears to be a Bosch VE. If anyone knows the exact model number, that would be really helpful. (Probably the same as what is in the Maxima).

Thanks,
Don

[DieselBuddy]

Front Damper replaced ?

I would look at everything you could with the oil pan off ( all bolts tight on the connecting rods, main bearing caps, flywheel bolts, etc. etc. )

What is the condition of the Damper on the Front of the Engine ?

[diesel-man]

Hello,

I have a marine-configured LD28 in a 1986 albin 27 boat. An "LD28M". It starts well and runs nicely, except that below 1100rpm it runs very rough. No smoke. A lot of vibration from idle up to 1100. Smooths out above 1100rpm or so. Rough whether cold or warm. Has about 3300 hours.

I'm hoping someone may be able to point me in the right direction to fix this. Is there a common problem with the LD28 that will cause it to run rough at low rpm?

I'm going to have the injectors cleaned, refurbished, tested etc.

I'm wondering if I possibly have a problem with the pump. Yikes. The pump appears to be a Bosch VE. If anyone knows the exact model number, that would be really helpful. (Probably the same as what is in the Maxima).

Thanks,
Don

Don:
Loosen each injector line (one at a time at the injector) while running to determine which cylinder is not making power. Check valve adjustment especially on that cylinder, but do them all. If no change, then pull that injector and put in another one. If no change, take a compression reading to see if one cylinder has low compression. Valve adjustment, injector then rings/cylinder. Hope this helps.

[DieselBuddy]

Check Motor Mounts,

See FAQ's in this forum, other suggestions in similar forums

[asavage]

Three years later, I'm finally following up on an email that Don sent me, with a picture of his Albin LD28M flywheel and some hard numbers. The idea was for me to host his pic and make the info available for others, but it sorta fell through the cracks (more like hit near the bottom of my To-Do list). I apologize.

Subject: LD28M flywheel dimensions - followup
From: "Don Guy"
Date: Sun, January 24, 2010 4:25 pm

Hello Al,

A belated follow-up to the info you helped me with last spring.

I've got a marine-configured "LD28M" in a 1986 Albin 27 boat. I was looking for flywheel dimensions in order to get a new damper plate without first having to take it apart. In the end though I did take it apart to get the dimensions, so I was able to order the right part. I installed an R&D Marine 42AC8 damper plate and am very happy with it.

The mounting holes on the flywheel are 6x0.32in on a 10.625 bolt circle (6x8.1mm on 269.9 mm). As well, I've attached a picture of the flywheel.

Thanks again,
Don

(click on image for larger)