BJ40 with fuel problem (1 Viewer)

[Erwin]

I had after many years finally finished restoring, got plates on, and off I went.
It was working well for a few shorter trips, and then it will no more.
It started to stall, especially up hills, but also on plain ground. Looses power and stops.
It has grown worse, now it don't run for more than hundred meters.
If I prime it, it starts again and runs for another 100 meters.
When running idle, also at high revs, it will not stop.
Before resto, no problems. I have not done anything with the engine.

Originally I thought it could be sucking air into fuel system. But I have tried to isolate any leak by first connecting a small diesel canister directly to the feed pump, then removing return line, plugging pump inlet and led return go into a coke bottle. No difference.
Priming pump is replaced wit a new Bosch pump.
Check valves of feed pump are new.
I have checked fuel filter. OK. It was new, but still...

So what are my options?
New feed pump?
Injection pump problem?

Any input is appreciated.

 

[duncanrm]

Its possible your lift pump has failed.. check this video I made of a 2H pump that had failed.. similar symptoms to your engine..

edit.. just re-read and it does appear you've had your lift pump rebuilt..

 

[roscoFJ73]

hen removing return line, plugging pump inlet and led return go into a coke bottle. No difference.

Did any fuel come out of the return line?
Every thing ok inside the tank?

 

[Erwin]

Did any fuel come out of the return line?
Every thing ok inside the tank?

Yes, the coke bottle was 1/4 full after a short run with two stops, and 5 min of idle.
Tank should be fine since the problem is the same when running from a can.

 

[Erwin]

Its possible your lift pump has failed.. check this video I made of a 2H pump that had failed.. similar symptoms to your engine..

edit.. just re-read and it does appear you've had your lift pump rebuilt..

I am not sure with the lift pump. Next step will be bypassing it with an electric pump to see if that helps.

 

[roscoFJ73]

If you get a container with fuel and elevate it above the fuel inj pump, the gravity feed should negate the need for a lift pump.

 

[Erwin]

Yes, it was the lift pump. I have read these are extremely reliable, so after changing check valves I did not suspect that at first.
But when bypassing it with an electric pump it was running as a charm.
So next step is to pull it out. Could same problem as in duncanrm' s video, broken spring.

 

[Erwin]

Pump piston was completely stuck in old solidified oil. My bad, I was not aware these injection pumps need to be filled up with oil. Later versions of the pump are fed with oil from the engine. The pump was nearly empty. Lucky it was not the injection pump itself that was broken. I'm not sure if the oil is only for feed pump, or also high pressure unit.
Fill oil trough dipstick hole, approx. 200 ml. Regular engine oil.

 

[Jollopy41]

Yes, it was the lift pump. I have read these are extremely reliable, so after changing check valves I did not suspect that at first.
But when bypassing it with an electric pump it was running as a charm.
So next step is to pull it out. Could same problem as in duncanrm' s video, broken spring.

View attachment 2444788

Sorry for the off topic, but did I just notice that your fuel filter is not "stock" but has been replaced with a Parker diesel fuel filter? I hope I'm not mistaken because I have been wanting to do a fuel filter modification. The ones that separate the water from the diesel fuel, but maintaining the same mounting location as the OEM ones.

 

[Erwin]

@Jollopy41
Yes, it is a 10 micron Racor 120 series filter. Had to make bracket for it.

 

[Jollopy41]

@Jollopy41
Yes, it is a 10 micron Racor 120 series filter. Had to make bracket for it.

Great idea mate. One more project added to my list.