can a leaking return line make rough idle

[HankHill]

so I have replaced all 8 injectors and not my IP, the Ip has 73k miles on it and is 17 years old, injectors are all BB code and return lines new, fuel seeps out of one return line at a very minimal amount, ever since I installed them I have had a really bad idle shake and noticed today when I layed into her greyish smoke started pouring out which has never happened before. First start of the day the truck clicks over in a split second but lopes horribly and pours the same greyish smoke yes it is raw fuel not coolant I've talked to lots of people and the consensus is that my IP is so old it cannot fire off the new injectors, now before I dig myself deeper in the hole is there anything else I can look for? the truck also has a miss and local IP rebuild is $450 before tax and from a very reputable shop.

 

[Cincinnati Guy]

Yes it will.

 

[HankHill]

scratch what I said about it leaking a tad bit, its actually coming out alot and collecting in that cylinder glowplug hole and bubbling, I cannot tell if its the bottom of the return Tee or if its coming up from the injector! is that even possible for the diesel to come out of the injection bore? I'm gonna put my money on **** o rings and bad tee, good thing I have an extra kit, hopefully I wont disturb the rest of the bank theyve only been on for a week

 

[Cincinnati Guy]

Well it could be coming from the injector hole, there is a crush washer on the bottom of it when it seats with the head, but Id replace the orings first on the return cap and see if that fixes it, most likely the orings became brittle or just ripped.

 

[HankHill]

well I replaced the tee and o rings and no more leak, also retorqued the injector for some reason it was really loose, started back up and its not as bad of a shake anymore but didnt do much change

 

[HankHill]

bumping, can anyone give an opinion or anything else to look for, I tried to check my torque converter bolts but one of the bolts holding on the shield has the head rounded out so I tried for a half hour today with vicegrips and hitting them with a hammer but it wouldnt loosen up

 

[johnboggs21]

if you can, you could weld a nut to the top of the bolt. Then ya have something to get your wrench on, and the heat from welding would help it come out easier.

 

[Abull78]

I would slam a tank with some Diesel Kleen grey bottle. IP adjustment might not be completely out of reason either.

 

[LCAM-01XA]

Check your other injectors for looseness in the heads too - I had four of mine get loose, one of them did it twice too.

 

[HankHill]

thanks for the tips guys, going to weld a bolt to the torque converter shield, abull78 adding lots of diesel kleen to the tank was the first thing done I've only ran 1/4 tank so far, I'll try tightening the other injectors with a crescent wrench too

 

[HankHill]

well no injectors are loose, no return lines are busted, no holes in the frame rail fuel lines. I'm going to rule this as IP problems, if the truck sits for a few hours it will blow gray smoke for a minute when you start, if it sits overnight it will puff gray for a good 4-5 minutes, I don't think the torque converter would do that, truck lopes, as soon as you switch from neutral or park into and drive gear the timing of the engine slows wayyyyy down, when its in park it sounds decent but when its put it drive its like I can count each of the pistons firing (not really) but it just goes from fast to a slug and also starts to knock

 

[G. Mann]

Based on my experience of losing an IP it's my opinion that your Injection Pump is on it's way to heaven [or hell].. in any case it's dying.

The rough running is likely due to the loss of pressure from the IP as it wears. The loss of power after engine warm up goes hand in hand with the worn internals of the IP not providing a crisp crack pressure to the injectors.

 

[G. Mann]

Based on my experience of losing an IP it's my opinion that your Injection Pump is on it's way to heaven [or hell].. in any case it's dying.

The rough running is likely due to the loss of pressure from the IP as it wears. The loss of power after engine warm up goes hand in hand with the worn internals of the IP not providing a crisp crack pressure to the injectors.

 

[G. Mann]

Sorry for the double post. Something didn't function right.

Suggest that you get the right size deep socket and torque wrench to seat the injectors at the right torque spec. A crescent wrench isn't good enough in my book.

 

[aaron1976]

Sounds just like mine (7.3). I swapped a 6.9 IP into it and it ran much differently, better but it seemed that the timing was too far advanced and I couldn't get it to stop rattling. It idled like a cummins and didn't have much power and I turned the fuel up till it smoked the same amount as the 7.3 IP.

Mine idles rough and blows lots of smoke until it warms up has 71K miles on it. I lose power after it has warmed up a bit. New BB injectors and new return lines as well. IP is next I guess.