Cat 320D smoking white at idle,

[Vetech63]

. It sure makes you humble, looks like a $30,000 bill ahead of us

Oh gawd, DONT DO THAT.

 

[bccat]

Ok. You stated earlier that you had originally had issue with cylinder #1, and replaced that injector as well, correct? Did you inspect the cup that the injector sits in or the removed injector? With common rail any disturbance of fuel supply to one is problem for all. That said, if you don't have a perfect seat at tip of injector to cup, combustion gas can creep up forcing past tapered seat and aerate your fuel galley through a damaged injector or o-ring.
What I do for testing is kinda redneck, but hey, it works. Take an old injector line, cut it in half. Either slide the nuts off the line and plug with ball bearing or in a pinch, weld the end of the line shut where you cut it. Remove 1 injector line, cap off rail end and injector with your new hillbilly block off caps.

###***Note, super important ***###
If you've welded the ends, place some rags or an old pair of leather gloves on the ends to protect from pinhole streamers of fuel. This can't be stressed enough, the fuel is under high pressure and should be respected for the risk it presents.

Try to start you engine. How does it run, yes a dead miss on one hole, but you are looking for performance as far as throttle response, reduced smoke etc. If possible, I would have the fuel return off the head running to a bucket through clear hose if at all possible. This will tell you if you have aeration occurring as well. Is return coming out in small dribbles or forcefully jetting out as foam. Obviously foam indicates combustion or compression gases getting into fuel galley. Then you will repeat the procedure for each hole.
Do you have the means to see or measure the fuel pressures, both low side and high? This might be where a cat tech or at least his software would come in handy.
Best of luck and please be extremely careful with the information and suggestions. High pressure fuel poses an injection hazard. You cannot get to the hospital fast enough should that happen. Common sense and healthy respect of what you are doing, you'll do fine.

BTW what does your fuel/water separator look like? Any water present?

fuel / water separator looks nice and clean no air. What you said makes perfect sense.When priming with hand pump , I could hear air in the system around the head and the first secondary filter ( there,s 2) was getting air from somewhere, tech said the noise was the relief valve,seemed not right to me, but he was the expert, but bothered both of us.Is it possible that when priming the fuel system you could fill the culprit cyl full of fuel and or if valves are not seating you could get air into the system.The Mechanic that did the compression tests lost the copper washer on #1, went and got another one,probably not the correct one, that explains everything. Will get the correct 1, hopefully it hasn’t, damaged the injector tube.The head will have to come off .Hopefully it’s just valves not seating.Will keep you up dated, again thank you for all your help. Ken & Greg

 

[bccat]

fuel / water separator looks nice and clean no air. What you said makes perfect sense.When priming with hand pump , I could hear air in the system around the head and the first secondary filter ( there,s 2) was getting air from somewhere, tech said the noise was the relief valve,seemed not right to me, but he was the expert, but bothered both of us.Is it possible that when priming the fuel system you could fill the culprit cyl full of fuel and or if valves are not seating you could get air into the system.The Mechanic that did the compression tests lost the copper washer on #1, went and got another one,probably not the correct one, that explains everything. Will get the correct 1, hopefully it hasn’t, damaged the injector tube.The head will have to come off .Hopefully it’s just valves not seating.Will keep you up dated, again thank you for all your help. Ken & Greg

Found smoking problems, #4 injector had a damaged o ring, just light smoke, now to pull head to see what’s going on with #1 low compression. Will keep you updated

 

[funwithfuel]

Wouldn't you want to reseal number 4 and see how it behaves. If it behaves good and run smooth why mess with it

 

[funwithfuel]

And have you run your valves yet ? You've had the valve cover off checking injectors but have you run your valves?

 

[bccat]

Wouldn't you want to reseal number 4 and see how it behaves. If it behaves good and run smooth why mess with it

We resealed the injector, runs with a slight miss

 

[bccat]

And have you run your valves yet ? You've had the valve cover off checking injectors but have you run your valves?

Fining tech said valves were a little loose, nothing that affects the low compression, took his word. Says the head has to come off, your thoughts

 

[funwithfuel]

Start your engine, let her warm up. Run hard a full throttle loading up with hydraulics. For example, hold bucket curled in while exercising arm in and out slowly. This keeps your pumps stroked up, keeps the engine loaded and avoids burning the oil cause you're cycling it through. Get your oil and coolant up to temp. Let her idle, pull the oil cap and see if you got excessive blow by.
If you're not pushing blow by, not overheating or washing oil out with fuel, I honestly don't see a reason to go after it.
Volvo runs low compression to start, we've had em so worn compression was in the 200's , still run like a top.
I'd clean up and reseal all cups and injectors. I'd run the valves myself. And lastly, I'd be absolutely positive my low side and high side fuel pressure was hitting its mark . Not a big fan of unnecessary repairs, big fan of root cause. It's a slippery slope and easy to get tunnel vision.

 

[bccat]

Start your engine, let her warm up. Run hard a full throttle loading up with hydraulics. For example, hold bucket curled in while exercising arm in and out slowly. This keeps your pumps stroked up, keeps the engine loaded and avoids burning the oil cause you're cycling it through. Get your oil and coolant up to temp. Let her idle, pull the oil cap and see if you got excessive blow by.
If you're not pushing blow by, not overheating or washing oil out with fuel, I honestly don't see a reason to go after it.
Volvo runs low compression to start, we've had em so worn compression was in the 200's , still run like a top.
I'd clean up and reseal all cups and injectors. I'd run the valves myself. And lastly, I'd be absolutely positive my low side and high side fuel pressure was hitting its mark . Not a big fan of unnecessary repairs, big fan of root cause. It's a slippery slope and easy to get tunnel vision.

I agree, will suggest to my friend, there’s no blow by , not heating up, no fuel dilution, will set the valves, it’s worth a shot