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Topic: Lots of White Smoke (Read 7824 times) previous topic - next topic

Re: Lots of White Smoke

Reply #101 –
 The balance test , if you let the pressure bleed done in each line  long enough to make a change in the smoke will find the broken injector .  It may take a minute  or more for the smoke to change  output.
Barring that,  Please pull the injectors  for a bench test.  Bench test before  swapping as to isolate the problem as opposed to throwing parts at it and hope it sticks.

Re: Lots of White Smoke

Reply #102 –
Quote from: Protech Racing –
The balance test , if you let the pressure bleed done in each line  long enough to make a change in the smoke will find the broken injector .  It may take a minute  or more for the smoke to change  output.
Barring that,  Please pull the injectors  for a bench test.  Bench test before  swapping as to isolate the problem as opposed to throwing parts at it and hope it sticks.
The mechanic and I pulled all of the injectors and he is supposed to be testing them at his shop.  It's been a week and we haven't heard from him and we're dead in the water until he shows back up. 

Re: Lots of White Smoke

Reply #103 –
Quote from: The Soft Boulders –
The mechanic and I pulled all of the injectors and he is supposed to be testing them at his shop.  It's been a week and we haven't heard from him and we're dead in the water until he shows back up. 
Is the mechanic's name "Bubba" ?

Re: Lots of White Smoke

Reply #104 –
Did he number the injectors?

Re: Lots of White Smoke

Reply #105 –
Many years ago, I built an injector tester and rebuilt my own injectors. OK, I used a small square cab tilt hand pump out of a fire truck. The injector tester can be built from a variety of hydraulic jacks, etc. See photos below. I was looking for a nice fan pattern and about 2000 psi. Naturally diesel is used in the pump along with a liquid filled gauge so when the injector buzzes, the gauge will remain pretty steady and give an accurate reading.

Once the injectors have been removed and tested for pressure and pattern, it's easy to take them apart. With a big vise, use a breaker bar in the vise with a deep socket the size of the injector base. Then another breaker bar also with a deep socket to unscrew the top from the bottom. Some injectors require a large crescent wrench as they only have two flat sides.

OK, once the top has been unscrewed, you will find a spring and washer inside along with the injector in two parts, the body and the pintle. I would slide the pintle out and after cleaning everything, put the injector into a vise between wood, plastic or a soft metal. Then the seating area on the pintle gets a little valve grinding compound and the pintle is slid back into place with great care as not to let the compound touch the sides of the injector body. I would then chuck up a drill to the small tip on the top and spin the pintle rapidly lifting slightly once a second or so. After inspecting the pintle and injector mating surfaces, if there were any flaws left, I would repeat the process.

Once everything had been cleaned, I would assemble and then pressure test looking for about 2000 psi and a nice fan spray pattern. If the pressure was low, just using a thicker washer would allow the pressure to be brought up so all were close to each other.

This takes about 15 minutes for each injector once you get the hang of it.

Link to injector examples, diagrams: Types of Nozzle in IC Engine : Pintle Nozzle, Single Hole Nozzle, Multihole...

Pierce

Re: Lots of White Smoke

Reply #107 –
Quote from: Pierce & Gaylie Stewart –
Many years ago, I built an injector tester and rebuilt my own injectors. OK, I used a small square cab tilt hand pump out of a fire truck. The injector tester can be built from a variety of hydraulic jacks, etc. See photos below. I was looking for a nice fan pattern and about 2000 psi. Naturally diesel is used in the pump along with a liquid filled gauge so when the injector buzzes, the gauge will remain pretty steady and give an accurate reading.

Once the injectors have been removed and tested for pressure and pattern, it's easy to take them apart. With a big vise, use a breaker bar in the vise with a deep socket the size of the injector base. Then another breaker bar also with a deep socket to unscrew the top from the bottom. Some injectors require a large crescent wrench as they only have two flat sides.

OK, once the top has been unscrewed, you will find a spring and washer inside along with the injector in two parts, the body and the pintle. I would slide the pintle out and after cleaning everything, put the injector into a vise between wood, plastic or a soft metal. Then the seating area on the pintle gets a little valve grinding compound and the pintle is slid back into place with great care as not to let the compound touch the sides of the injector body. I would then chuck up a drill to the small tip on the top and spin the pintle rapidly lifting slightly once a second or so. After inspecting the pintle and injector mating surfaces, if there were any flaws left, I would repeat the process.

Once everything had been cleaned, I would assemble and then pressure test looking for about 2000 psi and a nice fan spray pattern. If the pressure was low, just using a thicker washer would allow the pressure to be brought up so all were close to each other.

This takes about 15 minutes for each injector once you get the hang of it.

Link to injector examples, diagrams: Types of Nozzle in IC Engine : Pintle Nozzle, Single Hole Nozzle, Multihole...

Pierce
That's a really cool setup!  If we were in a better situation I might try something like it.  I'm beginning to think that the mechanic is going to flake on us. 

Re: Lots of White Smoke

Reply #108 –
Since I already had the pump and scrounged the rest of the parts except for the gauge, it didn't cost more than $25 at the most. With a cold engine and a torn or straight stream for an injector pattern, it makes for hard starting and lots of smoke. Once the engine is warm, there is much less of a temperature rise needed so a bad pattern from an injector or two will not be noticeable while driving. The emissions will go up though. I still have the tester but it's in a garage over 500 miles away so can't show photos but it's a lot cruder than the nice ones in the photo.

All injectors are not the same and some have a tip that can be damaged if water gets in the fuel and is instantly vaporized as it's sprayed in.

If your diesel takes a couple seconds or more (sometimes a lot more) of cranking to start and when the engine does start, one or two cylinders take a few seconds to come on line, it's usually because of a bad spray pattern in those cylinders. With a Detroit 6V-92TA, this is common because of the lower compression ratio (17 to 1) on the turbo engines. That's one of the reasons I like to run injector cleaner in the fuel.

With electronic engines, it's a different game and as I recall, there are very few facilities in the U.S. that can rebuild electronic injectors. This may be changing as most all diesels today are electronic. I noticed an ebay ad for a tester for electronic engines but it was $54,000.

As you can see from this ebay page, it's easy to spend more for a set of injectors for some Cummins engines that an overhaul kit. The high prices are not exclusive to Cummins either. New technology comes with a price. cummins diesel 8.3 injectors | eBay . On the other hand, mechanical injectors are usually pretty cheap.

So, your mechanic probably sent the injectors to a shop specializing in injectors and that's probably responsible for the delay. I had a bad injector on an older Detroit mechanical engine and went to an injection shop in Sacramento. A rebuild unit injector (injection pump and injector in one unit) was only $50 so if you have a bad one, it's not the end of the world.

Pierce

Re: Lots of White Smoke

Reply #109 –
Since you've already got the injectors pulled why not run a leakdown test on each cylinder?  It will absolutely pinpoint problems with any cylinder be it rings, intake or exhaust valves, general condition including compression.  A kit for this is only around 50 bucks, simple to do. Requires a compressor and that you follow the procedure.  I use this device on every used engine considered for purchase.  It is an invaluable diagnostic tool.

Re: Lots of White Smoke

Reply #110 –
Chuck has an excellent tip. Here is a kit for most HD diesels: 34900 Diesel Compression Tester Tool Set Alt

Along with the compression tester is a differential pressure/ cylinder leakage tester. We use these on aircraft at every annual inspection. We put 80 psi into the tester. There is a restricted orifice between the two gauges. The second gauge will drop down and show the difference between cylinders and with your ear, you can tell where the leakage is by listening at the oil fill on the crankcase, the exhaust manifold and intake manifold. https://www.summitracing.com/parts/otc-5609?seid=srese1&gclid=CjwKCAjw3azoBRAXEiwA-_64OuPwjhGIWkfgjNs_gdwKGJiFz99wHzG_ftDHFHcsVcMf3ZPLsLzuIhoCmKoQAvD_BwE

After each cylinder is tested, we write down the result. Example 80/79 is excellent, 80/75 OK or 80/40 in the case of a severe leak. So you have six sets of numbers to keep in your record book. The next time, you can see if anything has changed.

Pierce

Re: Lots of White Smoke

Reply #111 –
Here is a video on how to do a cylinder leakdown test. The gauge is a little different than I use but the same principal. The engine must be stopped and on top dead center on the compression stroke. 2-cycles fire each time but still have to be at TDC.

https://www.youtube.com/watch?v=WgrfT0LFMhc

Re: Lots of White Smoke

Reply #112 –
I would be beside myself, after all this screwing  around, why NO ONE knows WTF happened?  :headwall:

Re: Lots of White Smoke

Reply #113 –
Thanks guys for all of the excellent information!  The leak down test sounds like it would be a good thing to try but I'm not sure if it is something we'll be able to do.  If the engine turns out to be bad we're going to have to come up with another plan of action.  We've already spent over 15 grand this year on repairs and with the issues that the coach still has it would be irresponsible to dump any significant amount more into it.  I don't really know what other choice we might have.  The machinist that did the manifold said he'd give us 5 grand sight unseen.  I'm not sure if we'd take that little for it but if the engine is bad and it's 20 grand to fix we'd be worse off.  There is a lot to figure out and hopefully we can get the engine back up and going.

It's difficult to move forward without injectors though.  The mechanic has not answered my calls or returned my messages for a couple days.  There's a good chance he's flaked on us and taken our injectors with him but hopefully he's just been busy and will get back with us soon.

 I called Cummins today to try and get a part # for the injectors but all they had was the Cummins pt # and not the Bosch one.  The service guy said they didn't really care to work on it but that they would if we can't find anything else.  However, they definitely will not look at it without injectors.  Looks like I could be figuring out how to reinstall injectors and putting everything back together again. 

Re: Lots of White Smoke

Reply #114 –
Where are you and  bus? 

Re: Lots of White Smoke

Reply #115 –
Parsons, WV.  The good news is that it's beautiful here and we're able to rent monthly.  Maybe we'll just settle here in WV.  As John Denver would say "Country roads, take me home to the place I belong". :)

Re: Lots of White Smoke

Reply #116 –
What oil are you using?Get a oil sample and see what the analisys is.Is the mechanic an independant or a shop,have someone else call him with a different number and see if he answers.Get the part number off the turbo and make sure it's the correct one.Is the oil level too high.

Re: Lots of White Smoke

Reply #117 –
To The Soft Boulders, I imagine that most of that $15,000 went into one time repairs and deferred mainanence.  So regarding your recent engine troubles, while you wait for either your mechanic to return, a trip to the salvage yard for a used set of injectors or eBay,  why not begin documenting the internal condition of your engine.

John44 brought up a good point about your engine lubricating oil.  Is it at the correct level?  As long has you have the dipstick in your hands, and starting with clean hands, wipe the dipstick oil onto your palm.  With your index finger does it feel like lubricating oil?  Rub your palms together briskly to create some heat stuff your nose into your cupped hands and sniff deeply.  Do you smell fuel oil?

You already own the barring tool and you've marked top dead center for #1 and #6 cylinders.  Beg borrow or buy a leak down tester and check the cylinders through the injector holes.  Your ears will tell you where the leaks are be it exhaust, intake or rings.

https://www.harborfreight.com/Cylinder-Leak-Down-Tester-62595.html

Engines that run, especially diesel engines that start well must be in pretty good condition, otherwise they wouldn't run.

Re: Lots of White Smoke

Reply #119 –
If I was able to get a leak down tester wouldn't I still need to find the correct adapter to fit in the hole for our specific injector?  It can't be a universal piece can it?