Problem with replaced Bmc 1500

[afright]

Hi ,I have replaced my engine with another 1500 in the summer, the replaced engine has been running fine ,this week took my boat to have a new canopy fitted which is about a two hour trip to the boat yard were it is being done, after about an hour the engine slightly revved up then reverted back to normal speed this occured about five or six times until I reached the boat yard,I did top up the fuel tank with 20ltrs of fuel,would this be a fuel problem I have fitted new injectors which I bought from Calcutt's,any info would be a great help many thanks.

[Tony Brooks]

Hi ,I have replaced my engine with another 1500 in the summer, the replaced engine has been running fine ,this week took my boat to have a new canopy fitted which is about a two hour trip to the boat yard were it is being done, after about an hour the engine slightly revved up then reverted back to normal speed this occured about five or six times until I reached the boat yard,I did top up the fuel tank with 20ltrs of fuel,would this be a fuel problem I have fitted new injectors which I bought from Calcutt's,any info would be a great help many thanks.

 

This is typical of any engine fitted with a hydraulic DPA injector pump when the injector pump runs short of fuel for ANY reason and most, but not all BMC 1.5s are so fitted. It might be that you were running out of fuel. I could be an air leak into the fuel system or insufficient bleeding or even when you topped up it stirred muck up in the tank that is now partially blocking the filter(s).

 

If the problem has now gone away it was probably low fuel but there are many other things like a blocked tank breather than might cause this.

Edited November 8, 2014 by Tony Brooks

[jonny]

Hi ,I have replaced my engine with another 1500 in the summer, the replaced engine has been running fine ,this week took my boat to have a new canopy fitted which is about a two hour trip to the boat yard were it is being done, after about an hour the engine slightly revved up then reverted back to normal speed this occured about five or six times until I reached the boat yard,I did top up the fuel tank with 20ltrs of fuel,would this be a fuel problem I have fitted new injectors which I bought from Calcutt's,any info would be a great help many thanks.

I had exactly the same problem many years ago with my BMC, I was constantly cleaning the lift pump filter, I tried cleaning the tank out but never managed it to perfection! ended up sawing two ins" off the lift pipe in the tank, and never had the problem again.

[afright]

Thanks will not know how it will perform until the return journey next week.

[Galeomma]

I had exactly the same problem many years ago with my BMC, I was constantly cleaning the lift pump filter, I tried cleaning the tank out but never managed it to perfection! ended up sawing two ins" off the lift pipe in the tank, and never had the problem again.

 

I presume you had to drain th tank and take the tube out from the bottom. I ask because my boat runs out of fuel wiith over 6 ' showing on the dipstick. I'd like to reduce that to about 3'.

[David Schweizer]

Hi ,I have replaced my engine with another 1500 in the summer, the replaced engine has been running fine ,this week took my boat to have a new canopy fitted which is about a two hour trip to the boat yard were it is being done, after about an hour the engine slightly revved up then reverted back to normal speed this occured about five or six times until I reached the boat yard,I did top up the fuel tank with 20ltrs of fuel,would this be a fuel problem I have fitted new injectors which I bought from Calcutt's,any info would be a great help many thanks.

 

Exactly the same has happened a couple of times on our BMC 1.5 wehen I failed to replace the fuel filter after 400 hours,(actually approaching 500 hours). On both occasions, I changed the fuel filter and the problem disappeared.

[afright]

Both fuel filters are new ,mind you one was not tight and had a very small weepage so I am hoping that this might be the problem,also the garage that we buy the red diesel from does not sell much in my area so just a thought it might be that which is the problem as well.

Edited November 9, 2014 by afright

[pete.i]

Both fuel filters are new ,mind you one was not tight and had a very small weepage so I am hoping that this might be the problem,also the garage that we buy the red diesel from does not sell much in my area so just a thought it might be that which is the problem as well.

that could cause it. When my BMC 1.5 did it I went round and tightened or replaced all the joints/olives in the fuel pipes and made sure I had no fuel weeps anywhere. If fuel can weep out then air can leak in. That cured my increasing rev problems.

[jonny]

 

I presume you had to drain th tank and take the tube out from the bottom. I ask because my boat runs out of fuel wiith over 6 ' showing on the dipstick. I'd like to reduce that to about 3'.

No I never drained the tank, as far as I know your lift pipe should enter the tank from the top, this is for safety reasons.

If your running out of fuel with 6" on the dip-stick I would assume your lift pipe is 6"to 7" from the bottom of your tank you could lengthen it for a smaller reading but also you might suck up a load of 'crud' if the tank is not clean,

[ditchcrawler]

 

Exactly the same has happened a couple of times on our BMC 1.5 wehen I failed to replace the fuel filter after 400 hours,(actually approaching 500 hours). On both occasions, I changed the fuel filter and the problem disappeared.

Not a BMC but exactly the same symptoms from a dirty primary filter.