Fuel pump functional test Nissan NS40D2

Tim Frank

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Life got in the way of splashing the boat until the past weekend.

Fuel delivery problem...either carbs need cleaning or fuel pump....leaning towards f/pump.

The Fuel System section of my manual says "General equipment required " includes a Fuel pressure gauge.

I cannot find any details of a fuel pump function test....but I have a small E/rude and the manual for it shows the procedure; should it work for my Nissan?

If so, anyone know the output value I should be looking for?
 

Sea Rider

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Re: Fuel pump functional test Nissan NS40D2

Fastest way to check. When engine starts to miss due to supossed fuel pump issues, keep priming bulb, if engine catches revs up it's a fuel pump failure. Internal diaphragams don't last eternally, probably dried, deformed, balooned or cracked. Check internal condition, replace worn parts and that's it.

Happy Boating
 

pvanv

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Re: Fuel pump functional test Nissan NS40D2

You can also use: Vacuum and Fuel Pump Tester, Part # 99998V701M, $29.58, but you can only measure pump suction...
Because the fuel pump is integral with the lower carb, a fuel pump issue is in fact a carb issue.
 

Tim Frank

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Re: Fuel pump functional test Nissan NS40D2

You can also use: Vacuum and Fuel Pump Tester, Part # 99998V701M, $29.58, but you can only measure pump suction...
Because the fuel pump is integral with the lower carb, a fuel pump issue is in fact a carb issue.

I have the OEM manual, but I can't find any quantitative test information.

I do have a vacuum and fuel pump tester (but not Part # 99998V701M).
Is there a suction value specified somewhere in the manual?
 

pvanv

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Re: Fuel pump functional test Nissan NS40D2

I don't know of any suction specs published for the 40D... but if you have about 10 inches of mercury vacuum, you should be fine. Regardless, since the pump is part of the carb, you will be taking the carb apart to service the pump.
 

Tim Frank

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Re: Fuel pump functional test Nissan NS40D2

I don't know of any suction specs published for the 40D... but if you have about 10 inches of mercury vacuum, you should be fine. Regardless, since the pump is part of the carb, you will be taking the carb apart to service the pump.

So it is not just a bolt-on to the side of the carb?
Parts are not that easy to get here....at least "small" parts.
If I have to take off that lower carb and open it up to do the fuel pump, I guess I'll need gaskets for the carb as well as fuel pump gaskets and diaphragm.

Carb kit (packaged for all 3 carbs is $170-:eek:)
 

Sea Rider

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Re: Fuel pump functional test Nissan NS40D2

If fuel pump is serviceable without removing carb, much better, If not remove carb from base and service fuel pump alone, no need to tear carb down as long you don't want to service carb too.

Happy Boating
 

TOHATSU GURU

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Re: Fuel pump functional test Nissan NS40D2

You can get parts for it from any Nissan, Mercury or Tohatsu dealer. The Mercury model is not sold in the U.S., but any Mercury dealer can look under the export models to get the numbers.
 
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