Fuel pump problem

[java gt]

Had a problem with my Moke and I thought I would ask here and see if anyone has come across the same issue.Over the Winter I would start the Moke which is fitted with a 998 and mechanical fuel pump every couple of weeks and it started everytime with little hesitation.Couple of weeks ago I went to start it and take it for a short run and it failed to proceed.After making sure it had spark,I discovered the float bowl bone dry so I checked the float was not stuck and I disconnected the pump and blew all the lines clear with a compressor.Took the pump off and as it appeared to pump when manually pressed I put it all back together and still nothing.Figured it was the pump after all so ordered a new SU pump.Fitted that and still nothing.I Heath Robinsoned a Facet pump I had to see would it start and away it went so I fitted a smaller Facet I had and blanked the manual pump hole.I tried both pumps manually and they seem to be pumping,my question is has anyone come across a problem like this before or did I miss something very simple.

[111Robin]

I currently have a similar problem with my '73 BMW. After about a week without running it was starting but running very slowly and rough but would eventually pick up after a few minutes and run fine. Fuel pump wasn't delivering when cranking but would work when removed and manually operated. I hooked up an SU electric pump after a few days and with the carb's primed on ignition before cranking it started on the button. So, lack of fuel diagnosed I fitted a new pump, same result. The pump can't deliver sufficient fuel to fill the carb's until the engine is running at fast idle, so eventually it does catch up and it runs fine. It's a low mileage car so I didn't suspect camshaft/pushrod wear but this is more than likely the cause. To keep the carb's filled I fitted a non-return valve in line and this works reasonably well but if left for a week it still struggles. Next thing I'm going to try is a primer bulb in line so I can manually prime the carb's and the whole length of the fuel line before cranking. My preference would be to fit an electric pump but for now this will do. It could also be an air leak in the line, reducing the efficiency of the pump, maybe due to degradation of the hoses from the fuel. It does seem to have crept up slowly as it has normally started first time even after a long lay up. Never had the same issue on a Mini but same principles apply, camshaft wear, air leaks, degrading hoses giving a cumulative effect of reducing the pump's ability to lift fuel and fill the carb' in a reasonable time when cranking. I also have the option of reducing the thickness of the insulator between pump/head to increase pump stroke to compensate for camshaft wear, I might try that if the manual primer doesn't work.

[Jt850]

Personally I wouldn’t bother with mechanical pump. Either fit the SU or I use the FuelMiser (FPE-135) on my 1275 (1310) with hif44. Tried a Facet, but pressure too high, and volume too low.

[Spider]

Is your Moke and Aussie Moke and what year is it ?