Stalling puzzle

[nzmal]

Our old Volvo runs sweetly but has an annoying stall that has me beat. The stall occurs when I throttle down from somewhere over 1200 rpm. If I throttle down at snails pace the stall is avoided but if I take the power off in a normal action, the revs drop and can't be recovered. I'm sure it's a fuel issue. I tried bypassing the fuel pump using a gravity feed but it made no difference. Could this be an injector problem?
I've bled the fuel lines and replaced some old piping then checked vacuum in the line.
There was water in the diesel and we drained that, but this problem has been with us for some time.
The engine restarts no problem after stalling... Any ideas?
Motor is 1976 md3b Volvo penta.


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[chouliha]

Had a similar problem with a Perkins 4107. Drove me nuts. Turned out to be the ant stall device. Had the injector pump rebuilt and it solved the problem

Good Luck

Chuck
Jacaranda
Tuamotus
French Polynesia



www.jacarandajourney.com

[sartorst]

Assuming that air in the fuel , quality etc have been eliminated and that the engine runs well otherwise I would think that the problem would be in the governing portion of the fuel system or kill lever ?

[nzmal]

Update.... Looks like it is air in the fuel... Getting bled again tomorrow. Mechanic talks of the air bubbling as the throttle pulls fuel through at higher revs, then settling together in a high point of fuel line when throttling off. Makes sense...we'll see

[nzmal]

Further update. All sorted now. Engine is running better than ever. Definitely air in fuel line. Replaced lift pump with electric one then checked line and connections. Copper washers missing from some banjo connections. PO had some fuel pump issues and a bit of a sloppy repair done.