There are a few methods out there about purging fluid from cylinders after injector swaps or maintenance. Some people go full Neanderthal, replacing injectors, pulling glow plugs, and cranking the motor to evacuate cylinders - resulting in a big, oily mess. Other people go more elegant, using a MityVac or cattle syringe to extract fluid via the injector nozzle hole.

Last night, I did my second injector swap. Following the instructions from Swamps (which are great, by the way), we removed the #7 and #8 injectors first, which did indeed allow almost all fluid to end up in those cylinders. We did end up with some in #6 as well. I used a cattle syringe for the first injector swap, and that was a pain. This time, I picked up a MityVac - much better.

Here's the kicker - even with the MityVac, working on the rear two cylinders sucks. Getting the tubing to sit in the cylinder just right to grab ALL fluid is near impossible. We thought we had it all. Just to be safe, we pulled the glow plugs, and hand-cranked the motor (24mm socket, 1/2" breaker bar). Out of the #7 cylinder came a fair amount of oil, enough to slosh over the side of the head. Was it enough to do damage had we not done that? I don't know, it wasn't that much, but I won't ever NOT do that method again.

My rule - if ever doing injector work, always take the time to pull the glow plugs and turn the motor over by hand.

 

And...how does it run?

 

I've still got some air in the system, so still a ten second crank while it builds ICP. Still have some smoke, though about half what I used to see on a 30F startup. Hoping that's related to the air in the system. I just filled up and ran the heck out of it for 15 miles. We'll see tomorrow morning.

 

What did you all change with this set of injectors? My truck smokes like a banshee on cold startup and white Buffalo told me you were having the same issues. I'd be interested in what you did to get rid of it or lessen it .

 

Last April I put in a set of Swamps remans, 175/0's. I had been experiencing a ton of cold start smoke on the factory injectors. After thoroughly going through the usual cold start stuff, I pulled pulled the trigger on the Swamps injectors. The smoke remained.

I took some time off (it doesn't smoke too much during the summer starts), and got back into it this winter. I've gone through most everything in the past year. Live tuning for timing changes, compression test, full testing of the harness, swapping PCM and IDM with known good ones - nothing helped.

I read a fair amount of other threads with people seeming to have more and more issues with reman injectors. I reached out to Dave at Swamps, explaining all the testing I had done. He immediately offered to give me full credit on the remans towards a new set of AC's. He also backed up the fact that he, along with several other injector builders, have been seeing more of this issue than they have in the past. He wanted to know as much as me if the AC's would resolve the issue. If I indeed got all the air out during my drive today, I should know for sure tomorrow.

 

I have new 160/30 from PIS. I, like you, had cold start smoke on the 200k stock sticks. And the cold start smoke remains with the new sticks. I had DP tunes with the new sticks...cold start smoke. Have tunes from Cody....cold start smoke. Rebuilt the turbo.... Cold start smoke. I think it's valve guide seals.

 

I've been on FTE for several years and followed lots of threads but don't remember any one mentioning to pull the oil galley drain plugs before an injector change. I've only done one set of injectors and bought a mighty vac in preparation. I saw a video that diesel tech Ron did where he pulled the oil drains. I decided to try it. The little allen heads seem pretty soft so I used bit in a ratchet and tapped on the back of it while turning. All 4 came out with no problem. Only thing I didn't do was wait long enough for it to completely drain before pulling the injectors on the passenger side. If I had waited a few more minutes I don't think I would have had any fluid in any cylinders. As it was I had about 1 ounce in 1 cylinder that I could get out with the Mighty vac. Couldn't get any out of the other 7. I had the glow plugs out and because it was my first time doing this(read nervous about screwing something up) I pulled the motor through by hand then used a remote start button and turned it over with the starter. Got a little mist out of all cylinders but nothing else.


The plugs I'm talking about are at minute 3 in the video. Are you guys pulling these and I just missed it while reading?

 

You have to keep in mind that if you want to pull the rear injectors and let the oil drain into those cylinders, it's best to make sure one of those cylinders is not near the top. I figured that out the hard way once when I realized that hardly any oil had drained into #7. Roll the crank a little and a lot more went in.

 

I remove the oil galley plugs. But the engine is tipped back and the rear most plug is between the last two cylinders. You will have some oil left in the galley no matter.

 

Not only did I remove the plugs, but I stick my brake bleeder vacuum hose in there and suck out whatever I can.

For the fuel lines, with an FRx installed, you can draw out a good portion of the fuel as well. I drain the filter housing some, just to get some air in there so as not to pull any additional fuel in through the supply line. I then disconnect the return line from the FRx. Eventually the FRx open end will be plugged with my finger. I then disconnect one feed line from the filter housing, stick the brake bleeder hose on it, and then disconnect the other feed line. While operating the vacuum pump with one hand, I block the return fitting on the FRx. This allows air to draw in from the one open fuel feed line, through one head, back through the FRx, and then through the other head into the brake bleeder can. I'm sure I don't get it all, but it's a lot that doesn't end up in #7 or #8.

 

I've removed the two oil drain plugs in the heads each time. I've done nothing for the fuel, though. Maybe next time...hopefully, in 200k miles! We FILLED the MityVac canister (can't remember the capacity, but definitely a good amount) entirely from #7. No matter what the method and steps are, it still holds true to pull the glow plugs and crank by hand to finish the fluid evacuation. I just wanted to get that info out there.

 

I am curious to see what your result is on this. I as well have had this issue ever since I purchased my OBS 3 or so years ago. I replaced everything, and I mean everything on it. The only motor components that remain factory are the bottom end and heads. I had a cold start heavy smoke issue, replaced all the glow plugs, VCG, UVCH, GPR with a Stancor, Batteries, starter, and the list goes on and on. All parts were OEM except for the starter and GPR. Even the batteries are Motorcrafts. I run Rotella T6 5-40 all year around. I did this before I started modding the truck, then went to 160/0s from Rosewood, chip and so on. The truck still smokes just as bad as the day I got it, and actually I think it smokes a bit more with the cold idle and additional fuel. The truck runs great, starts within a second even when its well below 0. I simply have never been able to resolve the smoke issue when cold (40 or below). Once its above 40* its just a light haze and during the summer when above 55 its really not noticeable. But dear god its embarrasing during the winter. It will huff until you get in and drive it. With a straight through exhaust I swear you can hear each piston slap back by the tail pipe during combustion, right after it starts. I have just learned to live with it. I know its an OBS, but it really doesn't make much of a difference VS. a SD to me.

Regarding injector swaps. I have probably done 15 sets within the last year on others trucks. Many more the few years prior. I wouldn't call it neanderthal, but 4 or 6 bolts into the cover is more than enough to keep your spray inside. Takes maybe 3 minutes to put the covers back over and install the bolts. I even do it with everything removed including the VCG and UVCH. Install the new injectors prior evac, and crank to push the fluid out of the glow plug holes. I used to do the first crank with a breaker bar out of precaution, but now just barely hit the starter 4 or 5 times to get the first rev out of the crank, then push the rest holding the starter a few times for a couple seconds. Wait a minute for any trickle down and do it once more. It takes less than 10 minutes to do and I rarely ever get a single drip out from under the covers. ( I pride on doing the job without any oil hitting the ground or exmanifolds/motr) Using a syringe takes twice as long(or I'm slow as chit with one) and does not pull all the fluid IMO. Galley plugs are unnecessary in my book as well, but that is me and my method, just an extra step.

For those who are doing this over a day or two with other work on a motor. Many times when knocking off late at night and waiting till the morning to evac the cylinder and wrap the job up, a lot of the fluid will leak down past the rings...if not the majority of it.

I have had two motors in the past with DIY boys that came in with a bent rod on #8 due to not fully evacing the cylinder... both were PMR SD motors that were evaced with a syninge.


Anyways I'm looking forward to what you come up with, as maybe the rebuilt stage 1 injectors are truly the issue in my situation.

Vid before I did the injectors...like I said it starts right up now, runs nice and smooth, just smokes like a locamotive, much worse in this video. I swear its the tune...I have also done IDM PCM and all the other swaps you can possibly imagine....Verified with AE as well... I'm at a loss. I have seen others do it, but not as bad, and then I have seen trucks smoke next to nothing withe exact same modification as my truck...hence my brothers truck... It doesn't even haze on -30 degree starts in Montana!

 

Well Nossliw and Dan, just cranked it up this morning. 40 degrees, took a few seconds to start, but not long, so almost all of the air is purged. And I still have smoke. I've got less than I had before, and the idle is smoother cold, so the injectors upgrade was worth it. But there's still something else going on. Dan, I'm interested to hear your hypothesis for valve guide seals.

 

Usually when valve spring seals start going you will get a haze on decel, and the IDIs and 6.9 were more prominent of this issue than the 7.3s. How many miles are on your rig?

 

What else can it possibly be? I'm going to order the parts, round up a valve spring compressor, wait for the weather to get decent....and I'm changing them. This winter when is was cold, I didn't feel like I could let it idle more than a minute or two...didn't need to PO the new neighbors.

I've also went with two quarts of Hot Shot Secret Stiction Eliminator.....snake oil? Maybe....but I thought I'd give it a try. Not to reduce stiction on the injectors...try to devarnish the internals.