Hey guys finally got a problem on my 96 12v. I drove it two weeks ago and been parked since.
But today we had a cold front and itsprobally about 35 degress and i go to start it and starts right up but idles real rough and finally just died. And then wouldnt start back up until batterys died. So then i charged battery up to full and tryed again this time pushing a little on the gas. It cranked right up again but just super rough with a whole lot of white smoke then dies. No start again. So i been researching and i believe what people are telling me is a air leak in fuel line. I did prime the primer about 100 times and i can kinda hear air coming from somewhere up top but can find and no leaks i can see. Any one have any advice or anything hoping to get this thing running before it ices up.
well the air sound probabaly is the lift pump engaging the oferflow valve and thats a good thing . so the lift pump is probably working . i just found the two small fuel lines were sucking air and it creates a problem . the lines im talking about are the one feed from the tank - it starts from the tank and it goes to the corner of the valve cover and is attatched to the corner of the valve cover and goes down to the small fuel bowl pre heater thats a problem one and the other comes off the top of the lift pump and goes up to the large fuel canister and is attatched to a bajo bolt with a small bolt on top . to check the lift pump just take the rubber elbow off the lift pump be carefull not to destroy it and get a 5 gal can of fuel and put a hose in the container and attach the hose to the lift pump were you pulled the rubber off and if it starts and runs the lift is good and now you only need to look at thosr 2 steel lines -
A couple of points to consider. (1) it is not unusual for the steel lines that run from the tank along the frame to rust thru. (2) there is a flexible line that runs between the top rear corner of the engine (just in back of the fuel filter housing) and connects with the steel line at the frame.
I would remove this flexible line first and check it for leaks. This was the last thing I checked when I had a problem like you described. Wish I had checked it first!
ya thats the line i called the return line. Whats the best way to get in there remove filter are what lol. And if it matters this is one of the few times i pulled in driveway and nose it up. And what kind of line should i replace this with will a regular fuel hose work are look for something else.
Ok guys thanks alot. And i just figured if cummins sold some hose how long would i need. Just trying to make a one stop shop lol. If not napa it is i just want to try and get it going after work. And yes 5/16 for the win.
Sorry if I misread something earlier, but if you are having a problem with air getting into the fuel system, then this would mean you need to replace the 3/8" hose because this is a suction type line pulling fuel from the tank.
The 5/16" hose carries fuel back to the tank after it leaves the injector pump overflow valve and would not account for air in the fuel system.
The entire fuel system, return included, will let air in because a leak will break the vacuum and fuel will drain back to the tank sucking in air.
Return line leaks only let in air when the engine is off.
so guys which size hose do i need for the red on in the pic about to go to cummins in 30 minutes. So aint there a supply hose right in same area also because my truck did start then die when running. So maybe it could be supply hose.
Ok guys just a update i pulled the fuel filter all the fuel looked clean. And i pulled the fuel return hose which was a pain in the arse and i dont think that one is my problem still looked good i guess. But i did find on the water seperator sensor it has two wires one looked ripped off. But since its so cold out ima going to probally pull other rubber lines in that area and replace them and going to change and clean prefilter screen also replace the prefilter to fuel heater hose tommorow. Im kinda worried this aint my problem.
Ya i hope lol it has been changed before it was like a braided hose. Not sure if they come from factory like that. But yes i did what i could last night it gets dark so early and in the 30s in Tx so i was to much of a girl to continue. Frozen hands hitting stuff pissed me off. But i did find my water seperator sensors wire was broke so going to pick on up today and plan to get new hose on and maybe change another one thats by it. Also my truck has no fuel filter on it at the moment would that cause a bigger problem when it comes to bleeding the air out later. And stay around because i found some vacuum lines loose not sure if i knocked them loose are were already off. But will get you some pics later and hopefully tell me were they go lol. Thanks and will keep a update
Well as of now i got line changed prefilter cleaned and changed screen and replaced rubber return hose. I then primed it but didnt try to start it yet i did come across a couple of things. I believe my fuel heater sensor is broke as well as the the plug going to it. Didnt really look to hard into it yet. And i got a couple other lines then look like they need to be pluged in but they aint i will get pics today so maybe you guys know were they go.
Well guys i just want to say thanks i lucked out truck started today going to let it sit overnight and hopefully stays prime and starts again. But not to sure what the problem was the return hose looked ok but maybe not had cracks on ends on inside. Change fuel filter and o rings the shaft o ring was hard as a rock. And then a new prefilter and o ring on prefilter looked really shot hard and desinagrated looking. But just a couple questions guys about these pics i found.
First pic here it seems like its just a air release for the vacumm lines it sits under the brake booster near bottom of fire wall.
And second one it is just a plug in right top of the 10mm bleed screw on fuel filter it looks like nothing has been plugged in it for awhile not sure what its for.
And finally has anyone ever had a air leak at you boost gauge connection. I unhooked my hard plastic wire to get it out of the way then i plugged it back in. And now my boost max is 15psi were before it was going past 30 if i kept getting on it. Are maybe i just turned the boost controller knob on accident.
Often the little brass part that slips over the hose (ferrule) is only good for one time especially if the nut was overtightened.
Finger tight plus one turn with a wrench is plenty.
My local Naca doesn't even bother charging for the 1/8" ferrules that only cost 3¢/each.
Does anyone know what the sensor plug is for if anything. And also the i guess vacumm hose vent thingy lol. Just wanting to know if anything goes there or what thanks alot guys and i just drove my truck 300 miles this weekend without a problem.
Can't really tell by the picture but it could be someone disconnected the fuel heater, which is fine or the wires go to water in fuel sensor.
The WIF sensor is at the bottom of the filter.
Well i have the have the wif plugged in just weird i will get better pics today. And the fuel heater sensor is broke and plugs are burnt. Just wanna go thru this thing and get it up to par.
If you really get into looking around you'll find unused connectors all over the place.
Think they probably used the same wire harnesses for gassers with smog sensors.
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