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Fuel rail : diaphragm

L

laurent

New member
Hello everybody,
I have a problem with my Mercury Optimax 225CV year 1999.
My problem is the idle. RPM max is 4000 !
I inquired about recurentes failures of these engines and I found that the problem of air and gas diaphragm when they died cause idling problems. Indeed, during disassembly, I noticed they were dead. There diaphragm 1 is sold separately and the other two are not spare parts but assembled on the rail: so 1300 dollars.
My question is: can we cobble together a system? The diaphragm you have it the same size? the same diameter? I know that the shape of the steel is not the same. Can we get them separately? I am French, I speak on this forum as I can not to see this information in France.
Thank you in advance.
ps : sorry my english is not very good.
 
The fuel pressure diaphragm and air pressure diaphragms are not sold loose because the fuel rails are calibrated at the factory to give you the correct air and fuel ratios. You will see the the tracker diaphragm is sold loose as this is only used to absorb the pulses from the compressor. My advise is to try a scource a complete fuel rail, which may be very difficult as the motors are quite old and have change a lot.
 
MercGuru said:
The fuel pressure diaphragm and air pressure diaphragms are not sold loose because the fuel rails are calibrated at the factory to give you the correct air and fuel ratios. You will see the the tracker diaphragm is sold loose as this is only used to absorb the pulses from the compressor. My advise is to try a scource a complete fuel rail, which may be very difficult as the motors are quite old and have change a lot.
Click to expand...

thepelicanservices make the 3 sizes diaphrams...tracker, fuel regulator, and air regulator. No need to buy complete fuel rail. contact us. thanks.
 
toddieie said:
thepelicanservices make the 3 sizes diaphrams...tracker, fuel regulator, and air regulator. No need to buy complete fuel rail. contact us. thanks.
Click to expand...

I reply to your AD above, do you offer a calibration service too? The reason that the diaphragms are not sold as loose components is simply that they will need recalibrating once disassembled. The tolerance between fuel and air pressures is very close to 1 PSI, anything more or less will cause the stoichiometric mixture to be affected. Mercury use the air pressure to regulate fuel pressure keeping the fuel at 10 - 14 PSI ( model dependant ) above air pressure. These engines are very sensitive to fuel and air mixture, messing with this can have catastrophic results, thats If the environmental agencies don`t get you first!
 
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