So, two weeks ago she died with possible fuel contamination due to filter failure. I cleaned the injector and refitted but to no avail. The pump still appeared to be working as a blob of fuel would force out the injector line on kick over. The injector also squirts fuel out. A bosche injector tested said the spray was crap but he expected I'd still see smoke coming out the exhaust. I had none.
I replaced the fuel pump with a new unit and had smoke out the exhaust. She was difficult to start but eventually did so and ran poorly (with reduced power) which got worse and worse until finally she broke down and I was recovered home.
First questions:
1. if fuel is coming out the injector outside the engine it is for certain going to go into the cylinder at the 20:1 compression?
2. if any fuel gets into the engine (vaporised or not) will I get smoke on kick - or is it only for particles igniting?
Out of desperation I ordered 10 new injectors from China, the minimum because I have the 418cc engine with the longer (non Yanmar) injector. These might arrive in time (just!) but I'm also wondering how it works. Is it like this:
3. pressurised fuel comes down the middle hole of the three (outside wall) and to the tip. The force pushes the needle up and the fuel exits the 4 holes. The spring pushes the needle back down, closing the holes. If the spring is too strong fuel will not exit the holes. If too weak it could exit before pressure has built and so would 'dribble'.
There is a chance that my new fuel pump is broken. I've less of an idea on how this works
4. can anyone explain how the fuel pump works and what parts could potentially fail?
That's it - for now
Cheers!
Andrew
