Adventures in Injector Testing

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CarlosA
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Adventures in Injector Testing

Post by CarlosA »

I`m working on a little collection of pics & links from my pop testing journey. I have collected about 40 injectors including the not-so-good ones currently on my car. I plan to test and balance every single one that is still in good working shape, and rob parts off of all others.

Yesterday I dropped an injector shim and haven`t found it yet - really hurt losing one since they are so hard to find & buy. This shim kit I got from a veteran in the vw diesel biz - Justin @ Greaseworks. He collected it long ago. There are about 180 shims spanning 18 different sizes. They look dirty in this pic, but i`ve since cleaned all the dried up diesel off & soaked them in vinegar to remove any tiny bits of rust that might have formed.

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My injector tester is a Bosch EFEP-60H scored on eBay for $25 BIN. So far it seems to be in good shape, but i`m still waiting on a replacement bowl to show up before I can make sure it actually works. It had a M14/M14 line that i`ve since replaced with this m14/m12 $58 piece from rocken-tech

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And the tester & a few injectors:

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CarlosA
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Re: Adventures in Injector Testing

Post by CarlosA »

Here are the shims after cleaning & sorting:

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There are 6 or more of every size, and spanning 1.10 to 1.95mm - however, since shims are inherently not precise (within .02mm) I think this collection spans every size in 1/100th of a mm - if I get really patient I may be able to balance some injectors within a few PSI - between the available shims and lapping of the parts.

I also ended up with 48 total injectors to tear down, many of them will not have reuseable nozzles so this will at least beef up the shim set:

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Fatmobile
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Re: Adventures in Injector Testing

Post by Fatmobile »

Injectors are such an important part of getting an old diesel running right.
I used to have to go to the local diesel shop to have mine tested or have the bosch service center balance them, that isn't cheap.

Now I pay myself to check, balance or rebuild my own injectors.

It's so handy to be able to do this yourself, $25 for that tester sounds like a great deal.
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CarlosA
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Re: Adventures in Injector Testing

Post by CarlosA »

Fatmobile wrote:Injectors are such an important part of getting an old diesel running right.
I used to have to go to the local diesel shop to have mine tested or have the bosch service center balance them, that isn't cheap.

Now I pay myself to check, balance or rebuild my own injectors.

It's so handy to be able to do this yourself, $25 for that tester sounds like a great deal.

Yeah I got really lucky on the pop tester, its my second one. I agree - the car i`m working on now will be 10x better than I could ever get it without balancing the injectors. I hope one of the old sets of France or Germany nozzles will turn out to be usable after cleaning, etc.
CarlosA
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Re: Adventures in Injector Testing

Post by CarlosA »

Got my replacement canister today for the pop tester - so i`m ready to go.

I started by disassembling and checking all the injectors, i`m going to build all the best nozzles first, see how they do.

I have 16 France nozzles, 12 German nozzles, 2 india nozzles, and the rest are Brazil. I`ll start by ultrasonic cleaning all the France nozzles with some "special ultrasonic solution" designed for injector nozzles - and see how these do.

I am also going to experiment with the two (3) different injector styles.

1 style has a short spring, and short body
1 style has a long body, long spring
and the final style with no country of origin on the injector body, has a long body, short/medium length spring and a long thrust pin that rides on the needle.

Pics of the above differences will come soon.

As for actual pop testing - its a disaster. The best spray "fog" pattern was the worst looking set of German nozzles with major erosion around the needle, and generally poor condition - these were very old, very rusty, and in terrible appearance. Every other set either had a wild pop pressure (frozen nozzle) or sprayed off in whatever direction. Between 6 and 8 of the france nozzles have signs of rust and are frozen, i doubt they can be saved.

And why not just replace 4 nozzles and call it done? Because I want to DIY and see what the possibilities are - especially since good German nozzles cant really be found anymore. I will try to resist experimenting with Cerium Oxide and lapping in the needle seat .......
CarlosA
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Re: Adventures in Injector Testing

Post by CarlosA »

Here are some pics of the nozzles being ultrasonic cleaned, etc.

Also I want to stress that i`m not mixing up the needles & nozzles - they are very carefully being kept together! I know someone would come along and lose it about this... after all it is just an experiment.


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The first batch of nozzles - that aren`t froze up

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Ready to go into the special tray

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Ultrasonic cleaner machine & bucket of stuff I got from a diesel shop

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Nozzles & Needles situated in a special tray for the ultrasonic machine

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And a little action - 10 seconds after starting this is how they looked - after two more 5 minute cleanings they pretty much aren`t getting any cleaner. Letting them soak for now - I`ll pull them out tomorrow and see how they look.
CarlosA
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Re: Adventures in Injector Testing

Post by CarlosA »

7 More nozzles have freed up - I soaked them overnight in penetrating oil - with no luck, then put them in the ultrasonic for about 5 minutes & was able to get them apart. Going to go ahead and soak the remaining 7 indefinitely - nothing to lose here.

I will be testing out some Cerium Oxide on all the worst nozzles, just to see what sort of spray pattern can be restored. None of them have any signs of corrosion - the steel must be a very high grade.
mtran
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Re: Adventures in Injector Testing

Post by mtran »

Last time I try 50/50 atf/acetone with same vinager and find very good,alone acetone/atf dont do much on nozzles,next time I`ll do only vinager to see difference but I belive that vinager is BEST.
ps.I try to cook water/vinager for nozzles and don`t too much,that is when you don`t have ultrasonic.
I`ll improve my English
CarlosA
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Re: Adventures in Injector Testing

Post by CarlosA »

Vinegar was going to be my next try for freeing them up - I just didnt want to risk creating that black layer all over them, does that happen on this grade of steel?

I used vinegar to clean all my shims - they turned out flawless and smooth, almost like bead blasting would do.
mtran
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Re: Adventures in Injector Testing

Post by mtran »

Good point,
I lose bright look on pinatle,but in MY case that dont hurt anything.
I`ll improve my English
CarlosA
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Re: Adventures in Injector Testing

Post by CarlosA »

Yep, it turned the outsides black - but doesn`t matter. The needle was not affected by the vinegar and the 5 remaining frozen nozzles did not free up even boiling in vinegar for 30 minutes. No matter because of what follows...

Today I tested all of the nozzles in the order that I thought they might be good by appearance. Starting with the German nozzles I tested 4 and all streamed out so much fuel I couldn`t believe it. After testing 8 more French nozzles with the same result I started to wonder if something was wrong with the pop tester. I scrounged and found 4 injectors I hadn`t disassembled, they had Brazil nozzles - all four popped at 125~ and had a nice vapor like pattern.

Eventually I tested all the nozzles and ended up with just 6 super clean Brazil nozzles that are serviceable. I assume they were near new already and haven`t been worn out yet.

Installed a set of Brazils and the car runs better/smoother and has little to no smoke during cold start up. I popped the four I removed and they were better than the old nozzles above, but not really reusable.

So I guess in summary *none* of the old nozzles I collected are usable at the moment and ALL of them appear to leakdown rapidly, as I had to pump rapidly just to build pressure to register on the gauge - because of this leak down I don`t even think the tips of the needles could be lapped in to improve or restore the spray pattern.

On the side I will certainly be experimenting with restoring old nozzles, anyway.
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