Originally Posted by Capt Gill
Volvo boat engine
? Elect. high press. pump or lift
pump ? I'm not sure what you're saying here, seems like you're confusing the lift
pump w/the high press. injector pump
Sorry to confuse you Jack - Diesel
, lift pump. I thought this was a Cruiser;s forum for boaters so I didn't know it was necessary to say "boat". Also, in case of any confusion - the lift pump is sometimes called the "primary" and works on a cam on the side of the engine
- its just below the secondary fuel filter
(the one on the engine). The high pressure pump is on the other side of the engine and provides pressure to the 4 injectors. The injectors have two lines (one from the high pressure side and one leaving from the top of the injector (fuel overflow return) -they should all be routed back via the fuel
return line to the fuel tank
directly. Some are also fed back to the secondary fuel filter
(on the engine) but they can cause problems if they get air-locked. I guess the idea Perkins
had here was to be sure any crap from the top of the engine injector was filtered again.
I just recently pulled all the injectors and pumps (after 19 years) and had one injector that was not working and one other that was in dire need of a new nozzle. I worked for a month and a half - overhailed all the engine pumps, seals
, rubber hoses, Bowman classic water
jacket rubbers, the tubestack and the alternator
. One interesting note - the water
pump (which is a Jabsco
3270-0001) impeller had been in the engine for 19 years - never had to be changed out - but it WAS time ! I think its longevity was due to the "speedseal" which I installed on the pump (replaces the cover plate that holds the impeller in place) at a cost of $149 (from England) about 18 years ago. They really ARE worth the cost AND are real easy to remove - all it takes is a bit of thumb and index finger pressure to unscrew the nice big knurled knobs on the 4 screws.
And BTW - the "index" finger is the one between the thumb and the middle finger (count your thumb as a finger) - just in case you guys/gals in CA have more than five per hand :>)
The other reason I think why the impeller lasted so long was the fact that Canadian water temps are MUCH lower than southern waters, have less salt
and the engines run much cooler than in the south. Last year was my first trip south so the warmer waters took their toll on that rubber impeller.
This temp diff due to diff areas of the globe I have noticed sometimes causes arguments between some people on the subject of Perkins 4-108 running temps ! Probably other engines too.
Have a GREAT ONE and I sometimes take a BIG swig of Bahamian Rum
with Pineapple juice if I find I'm getting confused :>)