Hi there!
My 1959 B-275 that always starts and is used for occasional mowing decided not to start one day. I have spent many hours checking everything and am running out of ideas. This is such as simple engine and I can't seem to figure it out...maybe someone can help me with an advice.
I used original glow plugs for about 60 seconds, as usual, it would crank puffing some smoke but wouldn't try to fire. The battery is fully charged and cranks well.
First of all I tried puffing a little ether into intake (took air filter off too) while cranking without using glow plugs. It fires right away but dies as soon as I stop spraying. One time I kept spraying and it kept on running. I deducted that there must be a problem with fuel delivery system.
My lift pump does not have a manual primer lever so I had to crank with the starter, loosened bleeding screws and saw fuel pulsing out as I cranked. Not being sure if that was enough or not I bypassed lift pump and fit a small inline electric pump instead. Now when the key is on and I crack any of the bleeding screws the fuel gushes out with very good pressure/volume.
I bled the system by running the electric pump and losening bleed bolt on the fuel filter until bubbles stopped, then the same on the injection pump bleed screw on the top of it. Finally cracked injector supply pipe nuts and cranked engine, I could see fuel spitting out from all of them.
Still the same, does not even try to fire.
I then took injectors out, cleaned their seats, they look OK to me, also blew the injector pipes through, no problem there. I then removed each of the nuts/holders on the injector pump where pipes screw in, carefully removed springs and little valves from their seats, they were all clean, none was sticking or stuck. Switched on electric pump with valves out, huge volume of fuel gushing through all four holes (proves that there is plenty of fuel supplied to the injection pump). Assembled it all, bled again, still the same.
Removed pump inspection cover, made sure all valves operate up and down when cranking, also when I operate stop lever that it has effect on the pistons. The lever operates fine and is not stuck.
I then removed governor cap (my pump has pneumatic governor) to check the diaphragm and it is OK (not ruptured). Checked and blew out the pipes between governor and intake, all good. Intake butterfly valve operates fine.
Undid the banjo bolt where the fuel enters injection pump after the filter, thinking maybe there was a gauze filter inside to clean there but there is none.
Then I used excess fuel feature, i.e. pulled out stop lever. While cranking with throttle fully open and then returning it to the middle it started firing and finally started on 2 cylinders (guessing). Huge cloud of smoke and knock. I kept it going playing with throttle a bit, it started clearing shortly and got all four cylinders going, RPMs went way up and as soon as it was running on all four cylinders it died again (starved with fuel?). I can repeat this any time but it does not help my mission. Maybe somewhat proves that there is still a problem with fuel delivery or air in lines?
I really feel that using electric pump and bleeding the system multiple times would at least enable one cylinder to attempt to fire, but nothing, nada.
Oh, I also removed valve cover to make sure all valves were going up and down when cranking and no valve was stuck.
Running out of ideas guys, will pick up a compression test kit shortly as compression and injectors are pretty much the only things I haven't checked yet....I just feel that an engine that ran fine and then sat for 2 weeks should not have suddenly lost compression or developed any other major mechanical issue...Also I think that probability of ALL injectors braking down at once is very low. Let's say even if 3 got debris in them, I should still hear maybe one cylinder trying to fire...
Any suggestions? Oh, and the weather is warm here in New Zealand, nearly summer. So cold is not an issue.
My 1959 B-275 that always starts and is used for occasional mowing decided not to start one day. I have spent many hours checking everything and am running out of ideas. This is such as simple engine and I can't seem to figure it out...maybe someone can help me with an advice.
I used original glow plugs for about 60 seconds, as usual, it would crank puffing some smoke but wouldn't try to fire. The battery is fully charged and cranks well.
First of all I tried puffing a little ether into intake (took air filter off too) while cranking without using glow plugs. It fires right away but dies as soon as I stop spraying. One time I kept spraying and it kept on running. I deducted that there must be a problem with fuel delivery system.
My lift pump does not have a manual primer lever so I had to crank with the starter, loosened bleeding screws and saw fuel pulsing out as I cranked. Not being sure if that was enough or not I bypassed lift pump and fit a small inline electric pump instead. Now when the key is on and I crack any of the bleeding screws the fuel gushes out with very good pressure/volume.
I bled the system by running the electric pump and losening bleed bolt on the fuel filter until bubbles stopped, then the same on the injection pump bleed screw on the top of it. Finally cracked injector supply pipe nuts and cranked engine, I could see fuel spitting out from all of them.
Still the same, does not even try to fire.
I then took injectors out, cleaned their seats, they look OK to me, also blew the injector pipes through, no problem there. I then removed each of the nuts/holders on the injector pump where pipes screw in, carefully removed springs and little valves from their seats, they were all clean, none was sticking or stuck. Switched on electric pump with valves out, huge volume of fuel gushing through all four holes (proves that there is plenty of fuel supplied to the injection pump). Assembled it all, bled again, still the same.
Removed pump inspection cover, made sure all valves operate up and down when cranking, also when I operate stop lever that it has effect on the pistons. The lever operates fine and is not stuck.
I then removed governor cap (my pump has pneumatic governor) to check the diaphragm and it is OK (not ruptured). Checked and blew out the pipes between governor and intake, all good. Intake butterfly valve operates fine.
Undid the banjo bolt where the fuel enters injection pump after the filter, thinking maybe there was a gauze filter inside to clean there but there is none.
Then I used excess fuel feature, i.e. pulled out stop lever. While cranking with throttle fully open and then returning it to the middle it started firing and finally started on 2 cylinders (guessing). Huge cloud of smoke and knock. I kept it going playing with throttle a bit, it started clearing shortly and got all four cylinders going, RPMs went way up and as soon as it was running on all four cylinders it died again (starved with fuel?). I can repeat this any time but it does not help my mission. Maybe somewhat proves that there is still a problem with fuel delivery or air in lines?
I really feel that using electric pump and bleeding the system multiple times would at least enable one cylinder to attempt to fire, but nothing, nada.
Oh, I also removed valve cover to make sure all valves were going up and down when cranking and no valve was stuck.
Running out of ideas guys, will pick up a compression test kit shortly as compression and injectors are pretty much the only things I haven't checked yet....I just feel that an engine that ran fine and then sat for 2 weeks should not have suddenly lost compression or developed any other major mechanical issue...Also I think that probability of ALL injectors braking down at once is very low. Let's say even if 3 got debris in them, I should still hear maybe one cylinder trying to fire...
Any suggestions? Oh, and the weather is warm here in New Zealand, nearly summer. So cold is not an issue.
