Best way to check prime?

[1 Patriot-of-many]

After replacing the glowplugs my 6.2 still is very hard starting cranking forever numerous times before it might start. I'm suspecting I'm losing prime after it sits overnight. Do I just crack an injector line? Thanks.

 

[papakb]

You can crack the filter bleed petcock and see if it has fuel there. I ran a tube down the edge of the cowl so that diesel fuel wouldn't crud up the panel and drain that into a bottle on the ground. You can also crack a fitting on an injector to bleed the system but that tends to make a mess of things because you have high pressure fuel there.

Kurt

 

[1 Patriot-of-many]

You can crack the filter bleed petcock and see if it has fuel there. I ran a tube down the edge of the cowl so that diesel fuel wouldn't crud up the panel and drain that into a bottle on the ground. You can also crack a fitting on an injector to bleed the system but that tends to make a mess of things because you have high pressure fuel there.

Kurt

curious, if I have a prime problem which it has to be, how do you get the fuel primed into the fuel injector pump? is there a primer like on the 939 series trucks somewhere?

 

[Blackmagic94]

Open the water separator first and see if it pisses out fuel. If it does then crack the back right injector line when you remove the dog house cover as it's easy to get too and crank till it pisses solid fuel.

 

[Bucho]

I know this post is old, but hopefully someone can help me out. I did a search on fuel and starting. Just picked up my buddies and it was last started in Sept at the inspection.
The gauge read empty so we added about 7 gallons of diesel. There is steady fuel coming out at the drain from the filter. We also pulled the filter to check it to make sure there wasn't anything bad in there. Can't replace because we don't have one, if someone does would you PM me. We have tried pressuring the tank with air and pulled the line the comes out of the filter house like the TM says to. Now we are on step of pulling the far back right injector line and crank until fuel comes out like this post says. Anything else we can do? How much fuel should be coming out also? Everything else seems to be working like wait to start light, just can get it to fire.

 

[Action]

You need to get air out of all the lines to the injectors. I cracked several of them, one at a time. The TM also has a troubleshooting section with flowcharts...It will ask a question..if YES, go here...if NO, go there, etc.

 

[Bucho]

I searched Operator and Maintenance TM. Volume 2 is the fuel system but I can't find a chart. If you know which that would be helpful, otherwise I will start searching again.

 

[cwc]

Did you check to see if the glowplugs are getting power?

 

[Action]

I searched Operator and Maintenance TM. Volume 2 is the fuel system but I can't find a chart. If you know which that would be helpful, otherwise I will start searching again.

It is in the first of the maintenance books under STARTABILITY TESTS

 

[Bucho]

Did you check to see if the glowplugs are getting power?

I believe they are, but I will confirm in there morning.

 

[Bucho]

It is in the first of the maintenance books under STARTABILITY TESTS

I will take a look.

 

[Bucho]

The glow plugs have power, the injector pump has power and I cracked the 2 lines that at the top as they are the only ones accessible with out removing the manifold. I have been cranking on it pretty good for just over an hour and still nothing. I did notice a little wetness out of one of the lines at the pump, but it is hardly anything. Do I continue to keep going this route?

On a side note I just found this behind the seat, passenger back.

 

[wheelspinner]

Try adding a little air pressure. Blow gun and a rag over the fuel fill. Pushes it through. Spent hours on a CUCV and it started in seconds like this.

 

[Bucho]

Try adding a little air pressure. Blow gun and a rag over the fuel fill. Pushes it through. Spent hours on a CUCV and it started in seconds like this.

I did that yesterday but I will give it another shot

 

[1 Patriot-of-many]

Put some clear hose from the pump to the return line see if you are getting bubbles of fuel through it. Are you gettin any smoke when cranking? Check your glow plugs resistance, each one. Just because you have power to them doesn't mean they are good. Ether destroyed mine both on the base and when I had a prime issue after I replaced the plugs.....Also check the top of the manifold for fuel. See if you have a pump seal leaking. My bet is glow plugs.

 

[Bucho]

The return line is the single hose that is connected to the 2 hard lines at the front of the motor and plugs into the top of the motor, correct?
No fuel in the top of the manifold as a leak would be. I do have 2 lines cracked right as them come out of the injector pump. I have been at it almost 2 hours and there is only a slight residue of fuel around where the injector lines are cracked at the pump. I can keep going, just worried at some point I am going to kill the starter.

Here is the pump.

How would I have fuel in the return line if I don't have anything here.
Not sure if you can tell from pic, but the wetness is minimal.

 

[Bucho]

Try adding a little air pressure. Blow gun and a rag over the fuel fill. Pushes it through. Spent hours on a CUCV and it started in seconds like this.

With the pressure I have added to the system via the filler neck, fuel dumps out of the strainer at the filter. Still nothing though.

 

[Bucho]

Put some clear hose from the pump to the return line see if you are getting bubbles of fuel through it. Are you gettin any smoke when cranking? Check your glow plugs resistance, each one. Just because you have power to them doesn't mean they are good. Ether destroyed mine both on the base and when I had a prime issue after I replaced the plugs.....Also check the top of the manifold for fuel. See if you have a pump seal leaking. My bet is glow plugs.

No smoke that I can see.

 

[Action]

Don't open the lines at the injector pump. Do it where the line connects to the injectors.

 

[Bucho]

Don't open the lines at the injector pump. Do it where the line connects to the injectors.

Ok closed.