running ruff
 

Ok here is the story. I bought this 12 valve motor to put in my 78 ford and im trying to get it going. I got every thing together and started it up and it ran fine off idle but would spit and sputter white smoke one it was revved and held at high rpm. It didn't smoke at all when reved up. So a friend of mine suggested cleaning the injectors because it had been sitting for a while. So i did and had them tested and they were better but not perfect. I installed them and it ran the same. So i orderd new injectors and installed them bt before i put the fuel lines on i turned the motor over to see if the pump was working properly and only 4 of the delivery vavles where pumpen out fuel. Could i have a clogged valve, can the be cleaned? I am new to the 12 valve so any help would be appreicated

welcome to diesel bombers and we will put you back up front to see if we can get a p7100 guru to help on this :humm:

well i think you need to get all the fuel lines back on bleed it get it running and check your fuel pressure to see where its at then you could determine if its lift pump,ofv or the fuel pump itself that is causing problems :humm:

thanx this seemed to be a good place to get advice. OK i will have to give that a try thanx for the advice:tu:

I'm fighting the same problem with my 12v at the moment. I have to check the fp yet, ofv, timing and look to see if there's any air leaks in the supply line... Let me know what u findout and I'll do the same :c:

what should i do to check the ofv?

If ur fp is low, u pinch the rubber hose coming from the ofv to see if the pressue rises any.

well i can't get it start is my current problem it won't push any fuel through the injection lines so is it safe to say my lift pump is bad?

That would be my first guess... Crack the banjo bolt feeding the pump loose and use the priming bulb on the filter housing and see if clear fuel comes out (not any bubbles or foam) retighten and try to start it again. Could have slipped timing too?

ya i have done that it has fuel going into the feed, but i took the ofv off the return and there is no fuel coming out the return. could something have found its way inside and plugged the inection pump?

So'So your not gettin any fuel out of the return when the truck is turning over?

no sir none at all

Alright soooo it ran when you got it and now it doesn't run. What did you change from then to now? It might be time for a trip to the Cummins shop If your not getting any fuel out of the pump itself.

ok im back to the lift pump being bad i hooked a small electric fuel pump off of my old gas motor and i had fuel to the pump and coming out the return so hopefully on monday i can get a new lift pump and all will be well. would hooking up that electric pump inline with the new mechanical pump be an advantage of any kind just a thought.

the electric pump would need to pump more fuel than the mechanical pump or you will starve the pump and it will go out..... thats what i heard anyway cause i wanted to put a lift pump off a 24v on my truck

I never thought of that, so defitley not adding the elctric pump lol

Or your could get an AirDog and ditch the factory setup all together... Thats what Im gonna do when I get enough coin :pca1:

Yea i would love to but i am spending to much on this all ready. I ended up replacing the lift pump and deleted the fuel heater. I got it to start but it was a short victory it ran like hell for a min and died and wouldn't restart. I pinched the ofv line and it was hittin like it wanted to start bt wouldn't. I think im just going to get a new ofv tomaro and go from there.

What fuel tank and fuel canister/pickup are you using?

its all new stock replacement 78 ford and i have my return line spliced into my fuel filler neck.

What kind of pickup tube does it use?

um its just a 3/8 steel in tank sending unit should i change to something different?

Just curious, as long as it's 3/8 that's good. Is there a filter on it or just the tube? I'm just thinking out loud...

just the tube im with ya i have been trying to think of some thing i missed. im hopen this ofv is the problem