Bad injector?

[Box]

Hello All..........I started and I tought sent this post a few minutes ago but I don't see it so I guess it did not post for some reason.

I want to run buy you guys an issue I am having with my 1610D. To see if anyone else has had this issue come up. First a little history, I recently replaced the head gasket, water pump and had the head rebuilt. This cured a problem I was having with the coolant overflowing the overflow bottle but now I have what I think is a an injector going bad.

I had to pull the injectors when I took the head in to be checked and rebuilt and I am afraid I may have somehow damaged one of them. The issue I am seeing is this. When I throttle up from idle to a higher rpm I get some white/grey (not completely white) smoke for a split second. Then once I reach the higher rpm I need it goes away and if the load does not increase to pull the engine down to a lower rpm (IE....more fuel needed) the grey white smoke will not return. At first I tought this smoke might be due to one of the valves seals not being installed correctly when they did the rebuild, but after using the tractor for a few weekends I think the issue is an injector that is going bad. The tractor appears to be using more fuel than it has in the past. I have tried to check for a bad injector, but the engine will miss if I loosen any of the 3 lines so I am thinking I must have one that is working but is not spraying in the correct pattern. If this was a leaking valve guide I would think I would see some smoke at start up and I am not seeing that and I do not appear to be buring any oil.

I have ordered an injector from Hoye to see if I can use it to determine which injector is bad by swaping this new one for the current one in each cylinder.

Your ideas and input on what else I should check are appreciated.

Box

 

[Jagmandave]

I'm not sure you have a problem here, seems to me my 1602D does this, and I've been running it for years with no problems noted.

 

[MJPetersen]

You actually can pull the injectors and have them tested by a diesel shop. I happen to know a guy that would test my injectors for example for $10-15 if I brought them to him. It is a hand pump with a gauge so that you can see the pressure when the injector releases and also the spray pattern. A relative simple affair with a hand pump, gauge, and injector line. You could even make one easily enough using a portable power unit for a pump--just changing out the hyd oil for diesel, and using an old injector line. Cleanliness is VERY important. The spray pattern should be a fine mist in a even cone shape. Probably for you the problem is that the injector is not sealing properly and dribbing the fuel into the chamber.

You can also check them on the tractor but must bend your lines out so that the injector can be attached. But then it is harder to reattach the lines when you install a new injector.

Mike

 

[Box]

Mike - One of the things I have been wondering about is if I damaged one of the sealing washers and your comment makes me wonder even more about that now. I have ordered some of the chamber gaskets (washers) enough to replace all them on the engine so that is one of the things I am going to try. When I get the new injector. I know a shop that tests Cummins and DDC injectors, maybe they have something we can rig up to test these as well.

Jagmandave - I guess the real issue I have with the smoke is that the engine did not smoke like this before I worked on it and does now. Plus I am guessing this is causing some power loss. So I am going to try to do what I can to correct it. All that said the engine starts great, runs good and does pretty much everything I need it to do....so as I said it's the fact I know something is not right more than anything else that has me chasing this problem


Thanks for your input guys

 

[McDenny's]

Like mentioned before, you can have them "pop" tested. Putting a piece of card board under them while "popping" them of will also show the spray pattern. Right before they "pop", the shop will usually leave pressure on them to make sure there is no premature drips or leakage. If you some how ruined or scored the injector copper that sits on the injector that goes into the head you will usually get compression by the injector and you would see it. If the engine isn't skipping or has a fuel knock when throttling up, I am not so sure I would be to concerned. If you noticed that your using more fuel, I might check other things. If it isn't blowing allot of black smoke or has a severe loss of power, I myself would run it. If your machine has a few hours on it and you would feel better knowing your injectors are also "fresh" like your top end, then by all means do it. Just try to find a good shop that will treat you right.


Just my 2 cents,
Dennis

 

[Box]

Hi guys.........I wanted to post a follow up to this post I started by during the summer. I am now moved into my new home and have had some time to check a few things out on the tractor.

I had a grey smoke issue during the throttle up period.

First I eliminated the possiblity of a sticking or "bad" injector. They all seemed to be working fine.

Then I pulled the exhaust manilfold and muffler as an assembly and ran the engine. I tought I could at least determine which cylinder was the one given me trouble this way. To my surprize none of them produced any of the grey/white smoke. I ran the engine this way for probably 30 minutes trying to reproduce the issue. Then I pulled the muffler off the manifold and reintalled the manifold. I then ran the engine again and found no smoke. Finally I reinstalled the muffler and the smoke was back. So I guessed there was something (water, unburnt diesel or something else) left in the muffler from the previous blow head gasket problem. There was a greasy oil film in the exhaust tube where the muffler mounts to the manifold.

That was few weeks ago and I have seen less and less of the grey white some ever since that time. I think running the tractor under a more or less constant load while brush hogging has begun to burn off or out what ever was in the muffler. I ran it yesterday for about 4 hours and didn't see any smoke to speak of at all.

Thanks to everyone for the ideas and help they gave me on this issue.

Box

 

[SailorBob]

I might be tempted to take off the muffler and clean it out with some carb or brake cleaner. The let it dry out good before putting it back on. I bet that would get rid of the residue. I don't see how it could hurt the muffler

 

[MJPetersen]

That is great. Just work it hard and it will clean itself up. It is going in a good way.

Mike