Got an old Westerbeke 40. Worked pretty well, except for contaminated fuel.
Changed the primary filter, secondary, fuel lines from and to the tank, added biocide to fuel (too much).
Now the engine hold 500 rpm steadily, but 1500 rpm (kinda slow cruising speed for my boat) only briefly.
1500 rpm will be stable for few minutes, until the engine reach its running temperature - 180c. (Roughly, seems related, but it could be because of the few minutes spent warming up).
Troubleshooting.
- bypassed secondary filter - still happening
- bypassed fuel tank (from jerrycan of clean diesel) - heard to much biocide could be the cause
- added low pressure 12v lift diesel pump for trucks (0.4mpa). with or without, same issue
- no visible fuel leaks
- tried to bleed various bleeding points on the engine and injector pump during surge without noticeable effect.
- checked the return line flow. it is small and steady. routed it into a jerrycan. still same issue.
I have a fuel sensor switch on the top of the injector pump that trigger an alarm when the fuel reach enough pressure and the alarm stop when engine kicks off and pressure lower.(don't ask me why the previous pwner did that - I know it should be on the oil pressure side).
Anyhow,
Start the pump
Wait 8s - Alarm Ring
Start the engine
Runs fine for few minutes at 1500 rpm
Start to surge
Kill the engine
Wait 60s to hear the fuel alarm ring.
Start the engine again.
within less than a minute engine will surge again until bring back to cold.
Facts:
- Time for the surge depends on the engine beeing warm. this is 100% repro.
- lift Pump takes WAY more time to build pressure into the injector pump AFTER the engine did surge.
Mechanic want to remove and rebuild the injector pump.
My hypothesis is :
- there is a leak of some sort (I find it a coincidence that the pump gave up when I changed my filters)
Questions:
Is it possible to have an intake of air without leak of fuel, and could it be because of metal expansion when hot ? that would explain why the pump takes more time to flush out air after a surge, and the slow building of the air inside the injector pump body.
Video : check around 1:45 https://drive.google.com/open?id=0B3t8KLz_eQTpRzZqUXFIdW9BY2s
This having be driving me nuts for weeks, and I am close to despair.
I can move the boat around but with such low power it becomes dangereous with any swell or breeze.
Changed the primary filter, secondary, fuel lines from and to the tank, added biocide to fuel (too much).
Now the engine hold 500 rpm steadily, but 1500 rpm (kinda slow cruising speed for my boat) only briefly.
1500 rpm will be stable for few minutes, until the engine reach its running temperature - 180c. (Roughly, seems related, but it could be because of the few minutes spent warming up).
Troubleshooting.
- bypassed secondary filter - still happening
- bypassed fuel tank (from jerrycan of clean diesel) - heard to much biocide could be the cause
- added low pressure 12v lift diesel pump for trucks (0.4mpa). with or without, same issue
- no visible fuel leaks
- tried to bleed various bleeding points on the engine and injector pump during surge without noticeable effect.
- checked the return line flow. it is small and steady. routed it into a jerrycan. still same issue.
I have a fuel sensor switch on the top of the injector pump that trigger an alarm when the fuel reach enough pressure and the alarm stop when engine kicks off and pressure lower.(don't ask me why the previous pwner did that - I know it should be on the oil pressure side).
Anyhow,
Start the pump
Wait 8s - Alarm Ring
Start the engine
Runs fine for few minutes at 1500 rpm
Start to surge
Kill the engine
Wait 60s to hear the fuel alarm ring.
Start the engine again.
within less than a minute engine will surge again until bring back to cold.
Facts:
- Time for the surge depends on the engine beeing warm. this is 100% repro.
- lift Pump takes WAY more time to build pressure into the injector pump AFTER the engine did surge.
Mechanic want to remove and rebuild the injector pump.
My hypothesis is :
- there is a leak of some sort (I find it a coincidence that the pump gave up when I changed my filters)
Questions:
Is it possible to have an intake of air without leak of fuel, and could it be because of metal expansion when hot ? that would explain why the pump takes more time to flush out air after a surge, and the slow building of the air inside the injector pump body.
Video : check around 1:45 https://drive.google.com/open?id=0B3t8KLz_eQTpRzZqUXFIdW9BY2s
This having be driving me nuts for weeks, and I am close to despair.
I can move the boat around but with such low power it becomes dangereous with any swell or breeze.