shouldnt fuel be coming out of the return line on the pump?

[HANK1948]

my burban has been sitting a couple days and I went to start it yesterday, and nothing, she wants to start when I squrit a little ether but after thats burned it just cranks. So I checked fuel at the filter and there is, so I noticed that there is no fuel coming out of the return line (I have a piece of clear hose from the return line on the pump) after figuring that out I pulled off the line from the filter that goes to the injection pump and cranked it a couple of times, I saw fuel flowing, so Iam I assuming that the pump is bad I also have been having surging problems for a few months now and It doesnt start as easy as it did so why Iam I not seeing fuel from the return line?

[john8662]

Have you had a fuel leak on the injection pump prior to this? If you had a leak I'd suspect that your pump might have a leak on the throttle shaft and cold have leaked the fuel out of the pump enough to air lock it. Another suspect could be a completly plugged fuel return check valve on the top of the injection pump. This will cause the housing pressure to be too high, and won't allow the pump to generate the pressure it should. You might try unscrewing the fitting from the top of the pump to see if you get fuel out of the pump while cranking. If so, it's a plugged check valve, you can clean it, but best replace it.

[HANK1948]

john, I unscrewed the return check valve tonight and nothing, I have had a internal leaking pump(i think)Its been surging for awhile and I couldnt find any visable air leaks , so how can I get the air out of the pump if its air locked?

[john8662]

For an airlock situation, you can take a 3/4" open end wrench and loosen at least half of the injector lines at the injectors themselves. Loosen the line nuts to where they are finger loose. Then get back in the cab and crank in 10 second intervals, leaving enough time in between cranks for the starter to cool. I'd do this about 3 cycles, if you're not seeing fuel start seeping from the loose injector lines then you have a fuel supply problem either somewhere in the system or at the injection pump. But you may try that fourth, then fifth try. Good luck!

[HANK1948]

well, John I cracked 4 lines loose today and cranked it 4 separate times and finally got fuel to start seeping out but I was wondering sould I see fuel at the return line? I was not, well thats all I did today I did not try to start it I figure I could get some more input before I will try to start it . thanks for the help!

[john8662]

You probably won't get a steady stream out the return until the injection pump gets fully primed and has excess full to go out the return. You would mainly see the flow out the return with the engine running, I haven't taken note if I get any before it actually runs.

If you're getting a healthy seep from the loose injector nuts, as many as possibly, I just say 4 to start with but some are a pain to get to. At that point, make sure your batteries are fully charged and see if you can get it started. You'll have to tighten up all the injector nuts before they cylinders will fire (equivalent to taking a plug wire off on a gasser). May take a few cranks, but you should get some signs of life out of it at this point.

[britannic]

I had a split injector return line that pretty much dried up the main return line. Engine was a pig to start warm, and the leak was hard to find, since it was behind one of my alternators. It was big enough to cause problems and small enough not to be found right away.

[HANK1948]

I havent been able to get to my burban yet but when and if I get it started can I still expect to get the pump air locked again? or was it because it was sitting a couple of days? I know I need to get another pump

[HANK1948]

I havent been able to get to my burban yet but when and if I get it started can I still expect to get the pump air locked again? or was it because it was sitting a couple of days? I know I need to get another pump