S370 Beaver Injector Pump

[Ilikeurtractor]

The speed at which it cranks is independent of the fuel flow per crank. Even cranking slowly each injection will yield the same amount of fuel if things are working correctly. You can actually turn the engine over with a bar and socket on the front of the engine and you'll hear the injectors "popping" fuel at the time of injection (you have to listen carefully as it's not that loud - kind of makes a subtle, quick "vibration noise"). I'd focus on fuel getting to the pump at this point and make absolutely sure that is happening, even if it means running a new line to it, filling it with fuel while held vertical, bleeding it at the pump, and watching it go down as you crank the engine which it will if the pump is working correctly. Use some clear tubing for this. It certainly still could be the pump itself but I'd only look at that last.

 

[techwrtr2]

How about a temporary fuel supply to the pump, bypass everything? I did see fuel run from the bleeder but I really don't have method to verify flow. Project may have to wait a while longer, I'm going to add the power beyond kit to my JD since I have it and it's been on the shelf for years and use it to split wood. Or rent one. Catch up on everything else and ultimately pull the Beaver from its rather cramped home into the barn where I have good light and even a smattering of heat to keep my fingers movable.

 

[techwrtr2]

Stuck a new fuel filter on today. Opened the bleeder screw on the pump and saw bubbles as the filter filled and then eventually some fuel. No difference in the starting issue thought. I'm going to have to do some finagling to get a different fuel line in place, there's a screen covering the injector pump attached to the fan shroud.

 

[techwrtr2]

As an update to this old post... I have crap for compression on 1 cylinder and sort of better on the other. Ugh. Don't have time for this.

 

[techwrtr2]

And in other news... I really need to retest the compression. I decided today to address a minor problem which gave me a nagging feeling it might have major implications. In the course of trying to get the old beast to run, I'd replaced my fuel filter. Sometime after that, I discovered my entire tank of fuel drained out. Needless to say, I believe the old fuel lines the culprit so I replaced them and added fuel to test for leaks of which I found none. Things got interesting when I decided on a lark to try starting it. It cranked over much better, I don't understand why it would crank more readily when there's fuel versus not but it did. And then it started. The blankity blankity thing fired up and ran beautifully. I don't have much fuel in the tank so I shut it down after dancing around a little. A half hour later, I tried again. And it fired up again.

So I want to test compression with the engine warm to see what I get for results. But as long as the thing runs, I'm going to avoid going nuts with repairs I don't have the funds to complete.

 

[oliver28472]

Like!

 

[techwrtr2]

Kind of embarrassed that I didn't do this a long time ago. And also very glad I didn't buy an injection pump or tear the thing apart. Could have saved a lot of trouble and a little money. I think I'll end up doing an engine refresh soon, but I also think I can put it off for a bit. I hope.

 

[Ilikeurtractor]

...I don't understand why it would crank more readily when there's fuel versus not but it did.

Glad to hear the good results. My guess on the cranking when fuel is present is that it is burning somewhat while cranking therefore reducing some of the load on the starter and ultimately allowing the engine to crank faster (i.e. more power is being sent to the engine through the starter + burning fuel).

Technically, one should shut off the fuel supply valve or crack the injector lines when testing compression because these engines do supply a small amount of fuel even when the rack is in the "off" position which can causing readings to go a little higher than if no fuel is supplied.

 

[techwrtr2]

Your thoughts on why it cranks faster match my own. I'll plan to add a fuel shut off valve so when I test compression again, fuel will be cut.

 

[Jptech]

Glad to hear you got it running!!! I haven't had a chance to retest my compression, but maybe some of your luck will transfer over to me! I checked mine with the lines disconnected the last time. I'm going to check it again after I finish my Beer. I'll let you know what I get. -------------------John
:drink: