LB7: About to tackle my injectors, any pointers?
- Thread starter HaubSS
- Start date
Yes thanks again Brent. Unfortunately I have to take it back apart for a fuel leak. After about 80 miles I drained about 5 gallons of fuel/oil mixture. So I got a big leak somewhere. I'm thinking it's the return line on the drivers side. I was pretty tired and distracted when I put that side back together. SMH
Merchant Automotive has a nice set of hex valve cover bolts that I bought for my recent injector swap. IMO they are easier to deal with than the allen heads. I want to say they were 12 bucks. Also cheap online bought lower valve cover gaskets let me down and I had an oil leak. That's when I bought the hex bolts and genuine GM lower valve cover gaskets. Problem solved.
Thanks for the info. I actually ordered all new bolts and gaskets from LDS when I placed my order, so everything is all new. Including the fuel in the crankcase
damn that sucks. did you torque the HP lines tot he injectors? a lot of people don't because it takes a special socket to get on them and wrench tight is not enough. you can tighten them by and hand and think they are good to go but then hit them with a torque wrench and you'll be surprised at how much farther they will turn. did you replace the lines or just clean them? you might try torqing them before you tear it down. and drain the oil an refill the oil and see if that stops it. if you used new banjo seals and tightened them to torque spec and had the surfaces clean they shouldn't leak.
Yeah I didn't tq the hp lines. Just used my calibrated elbow. Honestly the gamble is not worth my engine so I'm taking the top valve covers off and gonna run the truck and see what I see. With that much fuel in the oil I feel the leak should be fairly evident.
your not going to take your motor out if you torque you lines change oil and run it 50 miles and see if its still making oil.
Ive seen LB7's come in with fuel coming out of the crankcase vent for a lot of miles and the engine is still fine. its worth a shot to retorque instead of tearing it all back apart. did you torque the retun line banjo's? did you torque the injectors down?
Yes I know for a fact the injector hold downs were tq'd, O-rings installed and lubed. I know for a fact the pass side return banjo bolts were all tq'd to spec. I cannot remember about the drivers side though. it was late and I was exhausted and distracted so i'm not ruling out the possibility that they were not tq'd.
thanks for the input. so I will do that, I will get a crowsfoot and check tq on the lines before I tear it apart. Just for piece of mind I think I am going to remove the lines and clean the corrosion off the fittings. I did not do this last time, and the reason for that is it was clear that the mating surface was corrosion free, but the surrounding area outside of the mating surface showed some corrosion. I figured it would be okay, but there is always that chance that the lines didn't line up in the exact same fashion and that is creating the leak. Or am I just being paranoid now?
thanks for the input. so I will do that, I will get a crowsfoot and check tq on the lines before I tear it apart. Just for piece of mind I think I am going to remove the lines and clean the corrosion off the fittings. I did not do this last time, and the reason for that is it was clear that the mating surface was corrosion free, but the surrounding area outside of the mating surface showed some corrosion. I figured it would be okay, but there is always that chance that the lines didn't line up in the exact same fashion and that is creating the leak. Or am I just being paranoid now?
CLR did wonders on my fuel lines. They looked brand new I'm not even kidding! Let them soak for half a day and blow them out with brake clean and compressed air real good
I used it and your right it does clean them up very well but when inspecting them I could see some crusty stuff on the inside of the fuel line in the small hole and very hard to clean I figured it its in that opening it could be all the way through the line. might have just been that one set but I didn't chance it and next dayed a new set of lines.
If you didn't clean the corrosion out and you put those lines on your new injectors there's a very good chance when threading the barrel nut down on the new injector that rust and crap can fall right into the new injector port. hopefully not but that can easily happen.
If I wanted to leak check the system do I need to have the truck running or will pressurizing the fuel system with my lift pump do the same thing?
You will have to have the truck running. The cp3 is what gives you your high pressures but be careful.
Gotcha. Well I got back into it and put a tq wrench on all 16 fittings for the pressure lines, each one was about 1/8-1/4 loose from spec at 35ftlb. A couple were nearly a full half turn loose. Does it sound likely that the lines being that loose could have been the source of my leak?
Yes those could leak. I've seen them leak at that much can. Change your oil and drive it and see what happens.
I want to thank everyone for all thier inputs and help along the way.
UPDATE: Still have a fuel leak, it seems to be diluting the oil at the same rate as it was prior to tq'ing the lines. Back to square one. Going to soak the lines in CLR and the Upper covers are coming off and I'm going to run the truck and see what's leaking. I simply cannot afford more trial and error. I'm over $200 in just oil already trying to troubleshoot this. I'm sure it's something dumb and small that I over looked, time to figure out what.
UPDATE: Still have a fuel leak, it seems to be diluting the oil at the same rate as it was prior to tq'ing the lines. Back to square one. Going to soak the lines in CLR and the Upper covers are coming off and I'm going to run the truck and see what's leaking. I simply cannot afford more trial and error. I'm over $200 in just oil already trying to troubleshoot this. I'm sure it's something dumb and small that I over looked, time to figure out what.
My money is on an improperly installed return gasket. Easy enough to do if you're side tracked or in a hurry.
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