VOLVO AD31P - Won't rev over 2000 rpm

P

pcm

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On trying my boat recently I found that the engine won't rev over 2000 rpm either in gear or in neutral. She's been laid up over winter but nothing else has been done to cause this - she was OK before lay-up. The tank is full with clean diesel so I wonder if anyone out there has any ideas about what I should be looking for????? Before going to the expense of calling in an engineer, is there anything obvious that I could look at??

Any advice greatly appreciated
 
Bondo

Bondo

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Re: VOLVO AD31P - Won't rev over 2000 rpm

Ayuh,... Being a Diesel,... Look for a restriction in the fuel, or air in, or exhaust out...
 
Don S

Don S

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Re: VOLVO AD31P - Won't rev over 2000 rpm

A few things to look for.
Check the air filter, if they get wet, it can really cause problems. Before you stored it, were the fuel filters changed? Are you sure you go all the air out when bleeding them? Asasuming you have the Racor installed, I have seen many of those caps leak air if the oring in the cap and the T handle are not replaced.
Check the turbo, make sure it's not stuck.
You should be seeing 4250?4350 rpm in neutral, and 4100 full load.
 
P

pcm

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Re: VOLVO AD31P - Won't rev over 2000 rpm

Thanks for your suggestions. I'll check out the fuel system. (I havent replaced the fuel filter since early last year). Just one thing that you suggested - the turbo - how do I check that it is'nt stuck?? Is this possible without serious stripdown??
Thanks again

Peter
 
Bondo

Bondo

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Re: VOLVO AD31P - Won't rev over 2000 rpm

Just one thing that you suggested - the turbo - how do I check that it is'nt stuck?? Is this possible without serious stripdown??
Click to expand...

Ayuh,... Just pull the intake boot off it,+ stick your finger in there,+ give it a Spin...
 
P

pcm

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Re: VOLVO AD31P - Won't rev over 2000 rpm

Have now checked out the fuel lines and found that there are two separate ones - one from the tank to the fuel **** and the other from the fuel **** to the fuel filter. Both of these are of the braided armour type but there are severe kinks in them in three places. I'm going to get replacements tomorrow but do you think that this could be the cause of my low revving problem???
 
Bondo

Bondo

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Re: VOLVO AD31P - Won't rev over 2000 rpm

Donno,... It could be Any restriction...

That's why Testing is cheaper than just replacing random parts...
 
Windykid

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Re: VOLVO AD31P - Won't rev over 2000 rpm

Change lines and filter, bleed system, and test. If no improvement, check fuel preasure.
 
P

pcm

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Re: VOLVO AD31P - Won't rev over 2000 rpm

Have now changed the pipes in question and the problem appears to have been resolved. Engine now revs freely to above 4000 rpm.
Thanks everyone
 
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