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KAD44 Surging under load

mgroo

New member
Hi all,
New to this forum, but looking for some guidance on my KAD44 installed in a 26' Osprey. Starts fine, no missing or smoke, can run up to 1500 in neutral no issues. Take it out, and once I start coming up in RPM under load, the engine starts surging rhythmically up and down. Changed primary and secondary fuel filters and purged fuel (not to the injectors), same issue. People tell me if it was air I'd get different systems. Bottom and props are clean.

Thoughts?
 
Run fuel from canister (feed and return) bypassing your TANK, and any RACOR FILTER.

Also, check air filter, and make sure your engine room has enough fresh air?
 
At what rpm is it surging? Is it between 2400 and 3000rpm somewhere? All those era of Volvo diesels have a wonderful 'feature' in that the turbos often don't last very long, and when the turbo boost drops the engine will not complete the handover between the supercharger and the turbocharger. Usually somewhere between 2400 and 3000 rpm's (depends on engine etc) the supercharger cuts out and the turbocharger is meant to be producing enough boost to take over feeding the engine. When the turbo goes weak there is not enough turbo boost to hold the rpm's up when the supercharger cuts out, so the rpm's drop down until the supercharger kicks in again. Does this sound like what is happening? How old and how many hours on the engine?
 
At what rpm is it surging? Is it between 2400 and 3000rpm somewhere? All those era of Volvo diesels have a wonderful 'feature' in that the turbos often don't last very long, and when the turbo boost drops the engine will not complete the handover between the supercharger and the turbocharger. Usually somewhere between 2400 and 3000 rpm's (depends on engine etc) the supercharger cuts out and the turbocharger is meant to be producing enough boost to take over feeding the engine. When the turbo goes weak there is not enough turbo boost to hold the rpm's up when the supercharger cuts out, so the rpm's drop down until the supercharger kicks in again. Does this sound like what is happening? How old and how many hours on the engine?

This is exactly what my KAD44P is doing. Thanks for this post, as it backs up my diagnosis. I just bought all the turbo seals and plan to pull it for rebuild.
 
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