wheelieking71

okay, im calling on the diesel guru's. this is my first CTD, so i am a little out of my element (been driving 72-84 dodge trucks my whole life thought). my truck had a pretty strange (to me) failure on the way home from work tonight. i gave it a 15minute once over in the dark with a flashlight after the wrecker dropped it in the driveway. and, here is what i know for sure: truck used about 1/4tank of fuel in about 50miles (i just filled it yesterday, and have gone 50miles and am down to 3/4tank). it started funny after work (first thing i really noticed). i let it sit and get up to temp after that before i left the shop. all seemed okay. got on the freeway, and it felt a little "doggy". i stabbed the throttle a couple times, and it seemed to pull okay but i felt like i was using more "pedal" than usual to maintain 65mph. its got my attention now, gauges were still good at this time. then i started to smell fuel real bad. looked in my mirror, and could see quite the "haze". thought it was exhaust. looked back at the gauges, NO OIL PRESSURE! temp climbing. was at an exit, got off immediately. probly took me 2 minutes after i saw no oil pressure to get it shut down. (i was stuck in center of three lanes at a red light, in traffic with no where to go) if i kept the revs up it had some oil pressure (and i did). after i got stopped is when i noticed the crazy amount of oil dripping from EVERYWHERE! and the oil was really thin, and smelled like fuel. the engine is externally bone dry from the oil pan up. and the wetness seems to be concentrated to the drivers side. coming from the crankcase vent is my best guess. and thats all i know. there is definately fuel in the oil thats left in the crankcase (still on dipstick), and it will still start and run. but it doesnt start like it used to. it starts right up, but its just different. and, it doesnt idle the same either. (i never let it run more than 5-10 seconds. i think i started it twice after the "shut-down) so, the things that immediately pop in my head are: hole in piston? injector stuck open? i am out of my element here guys, and could use some help diagnosing this.

wheelieking71

somebody on another forum (RCC, my usual hangout) suggested that the injection pump can spring a leak and dump fuel into the crankcase. and that could possibly make sense because i just replaced the stock diaphram lift pump with a brand new (cummins) piston lift pump 2 weekends ago. when i bought the truck a year ago i was told the pump was 1.5 years old. but im sure that was not true, and i have no idea of the pumps true age. i had to replace the pin O-ring a few months ago because fuel was dumping out the aneroid vent, if that tells anybody anything.

bulltamer

Sounds like the lift pump gave up the ghost and started dumping fuel in the crank case or the IP pushed out the front seal maybe some others will chime in

wheelieking71

this is the truck:

http://ramchargercentral.com/mopar-t...;s-last-rig!!/

wheelieking71

could the added volume/pressure have pushed the seal out? the lift pump is brand new! and a cummins part. (not a reman) how can i trouble shoot this? if i pull the oil-fill tube from the timing cover would i be able to see fuel leaking?

9MM

try searching injection pump front seal but yes excess pressure can blow that seal out.

If it is a new pump try getting a new one n see if that fixes it mighta been a default from the factory.

92smokin blacky

I'd pull the lift pump first and see if you can tell if its bad or not, or hook a fuel pressure gauge up to it quick to see if its pushin any fuel. The diaphram can go bad and leak fuel into the oil. We had this happen on a swather of ours once, the motor was so full of fuel after sitting all winter it would barely turn over.

If not it could be the front seal of the VE pump. You probably couldn't see if the seal was blown out from the filler tube hole cuz the pump gear would be in the way but I'd see if it smells like diesel really bad right there. Did your truck's oil level raise? as if fuel is in there? or does it smell full of fuel?

wheelieking71

the lift pump is a two week old, brand new, cummins part, piston pump. i dont know the history of the injection pump. yes there is definitely fuel in the crankcase. the oil on the dipstick is thin, and smells very strong of fuel, and so does/is all the oil coating the entire underside of my truck.

92smokin blacky

which piston pump? the low pressure one or one for a 2nd gen? if its a piston pump then I bet it was running too much pressure and blew out the VE front seal. Especially if the VE is an older pump. Only way to tell is pullin the Injection pump.

wheelieking71

2nd gen. part number: 4988747

92smokin blacky

Im betting that there is your problem and blew put the front seal. Ya gotta run a regulator with those 2nd gen piston pumps and keep the fuel pressure below 15 psi or it'll blow the seal. Some guys will get away with more pressure but its all in luck and how new your pump is.

wheelieking71

thank you greatly for the help! it makes perfect sense. i believe my injection pump to be pretty old. like i mentioned, i already had to replace the fuel pin O-ring because it was leaking out the aneroid-vent.

bannerd

This ^^

On the front seal make sure you lube it good with red lock tight. It helps to keep that from vibrating out or blowing out under pressure.

If a new lift pump doesn't do it then you might have a piston that has a worn out ring land? A compression test would know that. Although I doubt it is something in that area.

wheelieking71

so, when you guys say "blow out the seal", do you mean that the sealing lip of the seal fails, OR, the seal itself physically comes out of its bore? i am planning to pull the pump this weekend, and go through it. i have read quite a bit on the procedure. and i see mention of some O-rings that will be necessary that are not in the DGK-121 kit? i have one new kit, and the leftovers from another when i did my 366-spring/fuel-pin O-ring. i want to make sure i have everything im gonna need on hand. does anybody know the part#/s for the not included O-ring/s?

downhome

Just to be clear, you evidently have the higher pressure piston lift pump. Can't tell if you know that there is a low pressure piston lift pump that is the one that should be used (unless you want the high pressure one). The low pressure one doesn't need a regulator, doesn't blow your IP seals.

It's your call, but it looks like after fixing your IP, you can either regulate the high pressure LP or get the low pressure LP and not regulate it.