6.2L fuel leak

[KamikazeKunze]

Hey all,

I have sprung a mystery fuel leak. When my 84 1010 runs for over 10m I have a Fuel puddle under the passenger side. it’s leaking for up above and down onto the starter, then dribbles off the front drive shaft.
The fuel filter underside is dry, injectors look dry and nothing is wet under them when I run my fingers under them.
I’ve pulled the intake hoping for a smoking gun but nothing. I thought maybe it was the rubber fuel lines running from under the fuel filter to under the intake to the injection pump and lift pump. No dice.

I’m baffled because everything I can see or feel is dry.
Tomorrow I may remove the rear battery tray or see better the rear injectors.
I’ve smelled diesel when I shut it off since I owned for the last two years, but now I see fuel as well.

Do any of you have any ideas?

Any and all help is greatly appreciated.

thank you

edit: what’s the small countersunk hole under the injector?

 

[TGP (IL)]

Lift Pump on lower right front corner of the engine block is leaking or frame to pump hose.

Tom

 

[KamikazeKunze]

Lift Pump on lower right front corner of the engine block is leaking or frame to pump hose.

Tom

thanks Tom. I can see that the lift pump is damp on top but it’s at the front of the motor. I’ll check the frame to pump line as well. I may even drop the starter so I can peer up it and see.

 

[cucvrus]

The small hole under the delivery nozzle is where the glow plug is installed. I doubt it is leaking there. But there are many places that can leak. Finding the leak is the real challenge. Fixing the leak will be child's play. Good Luck. Be Safe.

 

[mike634]

Small hose running from injector to injector could be leaking if they are cracking.

 

[KamikazeKunze]

Small hose running from injector to injector could be leaking if they are cracking.

Mike634, are those return lines? I only ask because I’m a diesel noob and didn’t know if I have a bad injector that maybe has a high return rate. So if it uses those tiny hoses as a return maybe maybe it’s more than a old rubber hose.
I think the rear most injector has a cap on it.
Thanks for all of the input gents!

 

[cucvrus]

I have had and seen delivery nozzles that leaked externally. I changed them and the leak ended. Are all the nozzle nuts tight? And yes the rear 2 nozzles have caps on the back return fittings. Also the return lines running back the frame can rust/corrode/burn thru. I seen a few that were burnt thru behind Gen 2 from being shorted to positive current. Like I said finding it will be harder than fixing it. Good Luck.

 

[Abbylind]

CUCV is correct it could be the return fuel lines. Also check the o rings for the throttle shaft that runs through the IP. I had those leak. It ran down the gallery under the intake and out the back of the engine. Dripped down by the starter.
Good luck

 

[KamikazeKunze]

Update:

thank you all for chiming in.

i ran her with the intake off and the valley filled up with fuel.
i think it’s leaking from the throttle plunger at the base, it’s very clean when nothing else is.

So please give me your thoughts. Install a new IP or reman now, or see if I can repair the O ring or whatever is leaking. She has 31k on her.

thanks a bunch

 

[Tinstar]

Mileage means nothing.
Brand new IPs that sit on a shelf will degrade over time.

If the IP has never been rebuilt then it’s time.
Only Fix the leak and something else inside will fail soon.
You already have the intake off anyway.

 

[KamikazeKunze]

Ok, that’s the way I was leaning.....does anybody here have reputable place I can deal with to source one?

update: the plunger for the throttle definitely had corrosion and the seal around it is definitely hard and brittle.

got a quote from Napa for $1k ouch.
the guys at O’Riellys asked if I had the high altitude kit. WTH is that. I am at 4500 feet and spent a fair bit in the mountains so should I?
they quoted $625 for regular and $525 for high altitude.

thanks all

 

[richingalveston]

I used badger diesel
[FONT=Verdana,Arial,Tahoma,Calibri,Geneva,sans-serif]www.badgerdiesel.com/

They had a pretty quick turn around. mail them your pump and a check and they send you a rebuilt one.


[/FONT]

 

[Abbylind]

I got a rebuild kit from Gomers diesel. Took off the top cap and pulled the accelerator shaft out (you'll have to pull the intake manifold to get the shaft out.) Put new o rings on the shaft and buttoned it up. Installed new intake gaskets. Hasnt leaked since. Good luck

 

[KamikazeKunze]

Thanks guys. I replaced the print on the throttle plunger and am slapping her back together this weekend. I am however rebuilding a second one with a rebuild kit to have on hand.
I really appreciate all of your input!

 

[sovei]

Hi guys, anyone know if the CUCV fuel pipe (from the filter to the injection pump , 3 Inch pipe with threaded coupler) is interchangeable between the military and civil 6.2? Would an AN fitting (of what side I don't know) be a better fix> The CUCV fuel pipe is about $35.00 and GM wants way over $100.00 Thank you for any info!

 

[Sharecropper]

Hi guys, anyone know if the CUCV fuel pipe (from the filter to the injection pump , 3 Inch pipe with threaded coupler) is interchangeable between the military and civil 6.2? Would an AN fitting (of what side I don't know) be a better fix> The CUCV fuel pipe is about $35.00 and GM wants way over $100.00 Thank you for any info!

I changed out my fuel line to an -06AN line. I'm using a 6.5FFM but you can run the same line up to the OEM box filter if you choose. I posted details in my rebuild thread - https://www.steelsoldiers.com/threa...away-m1028-rebuild.54469/page-15#post-2222165

Hope this helps.

 

[sovei]

Actually, I just gave it a closer look and the only thing wet I found was this. Could this be a problem? O ring maybe? I will relace the other fitting with an AN fitting and line regardless.) Thank you gain for all your input in advance guys!

 

[Sharecropper]

Looks like you need a rebuild of your injection pump. Check all bolts and screws to make sure.

 

[sovei]

Thank you.

 

[sovei]

Wow, NAPA wants $1500.00 bucks for it. LOL