skydawg Posted October 1 Share Posted October 1 (edited) Has anyone ever tried to prime the fuel system by somehow creating a vacuum at the injection pump inlet hose? I`m not having any luck pressurizing the fuel tank.I`ve gone from 10 to 45 psi,after filling both filters.I don`t think there is any blockage in the tank..I can get fuel to the first filter inlet,but never any from the 2`nd filter outlet to the IP.At some point in it`s working cycle,is the lift pump "closed" to the fuel line from the tank? Could it be in the closed position from the last time I shut the engine off? Edited October 1 by skydawg Quote Link to comment https://www.bigmacktrucks.com/topic/74599-endt-673-fuel-priming-not-working/ Share on other sites More sharing options...
h67st Posted October 2 Share Posted October 2 So if you disconnect the inlet line from the lift pump, do you get fuel there? That would tell you if the problem is in the lift pump or before it. 2 Quote Link to comment https://www.bigmacktrucks.com/topic/74599-endt-673-fuel-priming-not-working/#findComment-559448 Share on other sites More sharing options...
Freightrain Posted October 4 Share Posted October 4 I would remove fuel lines at each point and pressurize tank and see where it stops. Do you have hand prime pump? Does it work? They can be pulled apart and clean check valves. When using the hand pump, it will fill everything and then start returning to the tank. I have had to reprime mine a few times in the last 23 yrs. 2 Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/74599-endt-673-fuel-priming-not-working/#findComment-559540 Share on other sites More sharing options...
Popular Post mechohaulic Posted October 5 Popular Post Share Posted October 5 does unit have two(2) spin-on filters ,or one spin-on with second being older scrapper cartridge filter ?? two fuel tanks or one ? has two , did you close off cross over valve so as to pressurize only one tank. some units had fuel supply on one tank with return to other tank > pressure to both tanks would pressurize the return also. no way would I recommend 45 psi to a fuel tank!! doesn't take that much. with super clean around transfer pump; remove caps/ hand pump check the nylon T shaped check valves. reinstall. filters full of fuel and SLIGHT pressure to tank having feed line ;; try to start unit. on occasion , with engine spinning the transfer pump working the fuel should move . stuck check valves may restrict fuel movement if pump not in motion. 3 Quote Link to comment https://www.bigmacktrucks.com/topic/74599-endt-673-fuel-priming-not-working/#findComment-559581 Share on other sites More sharing options...
skydawg Posted October 6 Author Share Posted October 6 No spin-on filters,one scraper and one cartridge(NAPA3390).Two tanks,I shut off the crossover and capped the vent on the feed tank.A local guy didn`t like the tank pressurizing,told me to loosen the injector inlet lines at the pump to bleed air while cranking the engine,and tighten them when fuel starts leaking past the fittings.Will try that tomorrow. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/74599-endt-673-fuel-priming-not-working/#findComment-559590 Share on other sites More sharing options...
Freightrain Posted October 7 Share Posted October 7 I've run mine out of fuel a couple times(not on purpose) and a few dozen pumps on the primer and away it went. 1 Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/74599-endt-673-fuel-priming-not-working/#findComment-559637 Share on other sites More sharing options...
mowerman Posted October 7 Share Posted October 7 haha I might be trying that soon might leaks like mad though I usually don’t even bother with it it only leaks when I loosen the wing nut Quote Link to comment https://www.bigmacktrucks.com/topic/74599-endt-673-fuel-priming-not-working/#findComment-559643 Share on other sites More sharing options...
skydawg Posted October 7 Author Share Posted October 7 I don`t have a primer on the lift pump. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/74599-endt-673-fuel-priming-not-working/#findComment-559644 Share on other sites More sharing options...
mowerman Posted October 7 Share Posted October 7 That’s really wierd frustrating collapsed line inside all that’s left Quote Link to comment https://www.bigmacktrucks.com/topic/74599-endt-673-fuel-priming-not-working/#findComment-559645 Share on other sites More sharing options...
mowerman Posted October 17 Share Posted October 17 Not sure if you got your truck running, but I think I ran mine out of fuel. I had it parked on a slope and I don’t think the fuel was reaching the tube. I was just out there and I had to blow air in the fuel tank and open the line on the pump, like five times before it caught As well as spraying ether and I have an air starter, you know what that’s like I had to keep refilling the air tank Quote Link to comment https://www.bigmacktrucks.com/topic/74599-endt-673-fuel-priming-not-working/#findComment-560239 Share on other sites More sharing options...
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