injector problem

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Re: injector problem

Post by optigman » Wed Aug 21, 2019 8:58 pm

Sometimes a bad air leak at the water valve packing is the culprit. As mentioned you should switch left to right and try the injectors and that will tell you instantly if it's a faulty injector or water line /delivery line issue. Another culprit is the injector overflow check valve being stuck. This is not the washer on the delivery cone. A stuck or restricted boiler check will prevent injector from putting water in the boiler. I had injector issues and I bought a 2 gallon galvanized bucket. I soldered a 5/16" brass barb fitting near the bottom edge and got clear 5/16" tube and hooked it to the water inlet of the injector. Make a new water pipe directly to the injector that accommodates the clear tube. Do not use what is on the locomotive. Assure all your water connections are perfect! This is a good way to test the injector and I could assure there was no air leaks as the clear tube would show bubbles. It also was handy to see how the injector lifted. The bucket can be placed on ground level below the injector or way up high to get a good hydrostatic head to feed the injector in case for some reason it does not lift. Finally another problem that I have is on hot days the water gets hot in the tender affecting the "dry range" of the injector. One of my injectors is very sensitive to the hot water and sometimes if too hot will not pick up. Filling the tender with fresh water that is not so hot solves the problem instantly. If your steam valve leaks and heats the injector it might not pick up. Grab an ice cold water and dump it over the injector and immediately turn water on and hit the steam valve to try to get it to pick up. One last thing in closing. I have seen a lump of debris sitting on top of the steam cone. Pull the injector and get a 10-32 screw and pull the steam cone. If needs be make a special puller to remove the steam cone. They are sometimes very difficult to remove.

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Re: injector problem

Post by kenrinc » Thu Aug 22, 2019 11:07 am

optigman wrote:
Wed Aug 21, 2019 8:58 pm
I have seen a lump of debris sitting on top of the steam cone. Pull the injector and get a 10-32 screw and pull the steam cone. If needs be make a special puller to remove the steam cone. They are sometimes very difficult to remove.
I had issues with mine for awhile. I talked with Barry about this on the phone before he passed. I had a big problems getting the steam cone out. He mentioned that it's a good idea to wipe a light coat of anti seize on the top, side edge of the cone before installing. I don't have much of a problem removing it now. For me, I HAVE to clean mine after every run or it will not pickup. If I was able to hook up some air and blow it out after a run it would probably help but I'm not there yet. I just pull out the checks and the cone. Check everything. For me, the vast majority of the time the washer is glued to the delivery cone. I have occasional forgotten to tighten the water delivery pipe nut when reinstalling and that's always a bummer. :mrgreen:


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Re: injector problem

Post by AnthonyDuarte » Thu Aug 22, 2019 11:53 am

I'll reiterate the notion of swapping the injectors. This is the surest way to quickly find out if it's the injector or the installation.
Having some limited experience with injectors, 10/10 times the issue is with the installation. No water filter, suction leak, restrictive check valve, injector installed backwards, etc...

It's astonishing how the slightest compromise in the water line will effect an injectors performance. The simpler the line between your valve and injector is, the better. Having a simple line with as few fittings as possible also makes it easier to identify any potential problem areas.

Recently I've noticed an alarming practice of soldering a short piece of tubing to the injector water inlet, then simply slipping fuel hose over it with a clamp. Or even slipping fuel hose over the injector connection itself. This is grossly inadequate. The line between your water valve and the injector is by far the most sensitive part of the system. A minor leak will cause a high starting pressure, and once it gets severe enough the injector won't work at all. At a bare minimum, a barbed fitting should at least be soldered to the end of the tubing so the hose has something to bite onto.

Disconnecting the delivery line and letting the injector discharge into atmosphere is also a good indicator. If the injector spits out a surprisingly powerful stream of hot water, then you're in good shape. Problem is elsewhere. If it's an unimpressive bubbly dribble out the delivery, then it's either a suction leak, or the check washer is stuck.

The water hose trick is a fantastic way to locate suction leaks, but unfortunately it doesn't work great if there is more than one leak.

Hoppercar, if you swap the injectors and it turns out there is an issue with the injector, I'd be happy to take a look at it.


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Re: injector problem

Post by Trainman4602 » Thu Aug 22, 2019 12:57 pm

Try swapping out the injector from the other side the working one. There could be something wrong with the injector

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Re: injector problem

Post by Jacob's dad » Thu Aug 22, 2019 1:00 pm

We had two brand new ones a while back on a new engine and it turned out the id of the puck was to tight on one of them. A couple of rounds with some crocus cloth and the problem was solved. Figuring that out was a nightmare to say the least. After that, it worked fine.

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