1HZ Bogging/Stalling out....HELP!!

[NateFFEMT]

Hey fellas, so my 1HZ in my 1992 j73 was running perfectly for the past 3 weeks (around 0 or -10 degrees Celsius ) then it gets cold.. like -20/30 degrees Celsius. So now it starts fine, then when I'm driving after warming it up for 10 minutes or so, it will bog down when i hit the gas, then eventually idle down and stall.... then it takes a couple tries to restart after. My initial guess was water/bad fuel, so i added some conditioner to the tank, replaced the fuel filter/ drained the sedimenter and it still does this... Is it the cold weather/ not warming up enough? water/Fuel problems? Priming pump has a leak? Any help is appreciated!

 

[Drewscruiser]

It could be sucking air into a fuel line, check all the fuel line connections and also it is quite common for it to suck air through the priming hand pump. If you can twist the top metal part of the primer pump thats a good sign that it won't be sealing properly and probably sucking air. Also could be a lift pump problem. e.g: not drawing enough fuel from the tank when cold, therefore starving the injector pump of fuel.

 

[arnott1t]

how old is the fuel? Any chance it is summer variety?

 

[NateFFEMT]

It is winter fuel... So upon further investigation.... Fuel lines are all tight, but the sedimenter drain is dripping diesel when its not running, then when it starts, it stops and they're is some mild suction on the drain... could it be sucking air through the sedimenter and into the engine?

 

[Squash]

Having just started a Cat Gen set in the cold fuelled by remote tanks I feel your pain. We actually had an iced up suction line as well as loose fittings.
Sounds like you are getting enough fuel to idle, but not enough to run.
Get a clear fuel line between filter and IP, a clear stream means ok, bubbles mean you are sucking air.
Air is most likely coming from filter housing so check and repair.
Otherwise bypass the filter by going to fuel line with clear hose as well, you could add an in-line filter temporarilly.

Your primer pump should get stiff after a couple pumps at least, best if tight the first pump. Run engine and try primer!
Other than that check your return line to tank, and lastly try with fuel cap off.

 

[Squash]

Ah!
There is your problem!

 

[roscoFJ73]

It is winter fuel... So upon further investigation.... Fuel lines are all tight, but the sedimenter drain is dripping diesel when its not running, then when it starts, it stops and they're is some mild suction on the drain... could it be sucking air through the sedimenter and into the engine?

That would be your problem. It starts and runs ok because the pump and injector lines have enough fuel to run for a short while

 

[NateFFEMT]

So i tightened the drain on the sedimenter, and also the fuel filter itself wasn't very tight on the pump.. so took it off, and re installed it tight this time, truck starts on first crank, drives, no stalls, no stuttering, works flawlessly!! Looks like a lil bit of air is a biggggg problem! But she's all fixed! Thanks for the help gents!