Re: Mechanical Fuel Injector (MFI) Tester and Cleaning Kit

[scoot]

I just two days ago finished using the my same kit to clean the HORRIBLY expensive injectors from my M189 engine.   I have a few comments about the cleaning kit, which probably belong elsewhere, but I'll include them here anyway.

First of all, it's well-worth the money.

My kit contained a small container of LocTite, with no explanation.  I have no idea what it is for.

The instructions are to test with Diesel first, and then carb cleaner.  What he doesn't tell you is how to get the diesel (or carb cleaner or whatever) out of the reservoir to switch fluids.  I made a big mess trying to unscrew mine and dump it.  Also he has you put a filter in the bottom of the reservoir -- there is no good way to empty it without reaching in and pulling out the filter.   Having said that, what worked for me was to clean as much as I wanted (do ALL of the diesel first and then ALL of the carb cleaner -- don't try to switch back and forth because it's just a big mess) I pumped the rest out of the reservoir into a bottle for toxic waste.  (without an injector attached).   I also bought the 5000 PSI gauge in case I want to use it with diesel injectors.

The biggest problem I had with the tester was getting a good seal between his hose and my injector seat.  Very difficult to get it tight enough that there was no leak-down.  Don't know if that is a statement about my injectors or his fitting or....

Anyway, mine are all better now.

[Jowe]

My kit contained a small container of LocTite, with no explanation.  I have no idea what it is for.

The instructions are to test with Diesel first, and then carb cleaner.  What he doesn't tell you is how to get the diesel (or carb cleaner or whatever) out of the reservoir to switch fluids.  I made a big mess trying to unscrew mine and dump it.  Also he has you put a filter in the bottom of the reservoir -- there is no good way to empty it without reaching in and pulling out the filter.   Having said that, what worked for me was to clean as much as I wanted (do ALL of the diesel first and then ALL of the carb cleaner -- don't try to switch back and forth because it's just a big mess) I pumped the rest out of the reservoir into a bottle for toxic waste.  (without an injector attached).   I also bought the 5000 PSI gauge in case I want to use it with diesel injectors.

The biggest problem I had with the tester was getting a good seal between his hose and my injector seat.  Very difficult to get it tight enough that there was no leak-down.  Don't know if that is a statement about my injectors or his fitting

Regarding the Loctite, I didn't get any in my kit. However, Kent maybe thought it would be useful to seal the threads with. I used own thread tape instead, as he recommends in the video and in the mounting instructions.

When it comes to exchanging the diesel with carb cleaner, I just pumped out as much diesel as possible through the injector and the hose to a closed container. Then, I just topped up with carb cleaner and continued the cleaning process. In fact, I think that the diesel itself made some cleaning work when stroking high pressure. After final stage, I of course needed to empty the container, filter, pump and hose thoroughly.

I didn't have any problems with the hose and the injector seats (R1 injectors). Maybe Kent has supplied with another hose type lately that fits better.

But, as you also assumed, the kit did a good work and I'm quiet satisfied, getting the injectors to a 180-200 psi release pressure and good spray patterns. Both the cold and especially the warm starts are much better and the overall running seems to be more "spiritual" after the treatment. Now the kit is on its way to Canada for another rescue of our beloved cars 

[Bonnyboy]

I told a mechanical friend of mine that I bought this tester over the weekend.  A new toy for the garage....

My friend said that in a shop where he worked long ago, the owner would accept/buy old mercedes cars for next to nothing to part out and/or resell.   Many times "reputable garages" told the car owners that the cost of repairs to get it running was more than the car was worth and he would even get some cars for free.  He said that more than a few times the cars were up and running and resold the same week car after a thorough steam cleaning and "secret" tweaks to the engine which was all done after hours when the staff went home.  His "secret" that he didn't openly share with his staff was the injector tester/cleaner that he kept at home. 

[scoot]

My friend said that in a shop where he worked long ago, the owner would accept/buy old mercedes cars for next to nothing to part out and/or resell.   Many times "reputable garages" told the car owners that the cost of repairs to get it running was more than the car was worth and he would even get some cars for free.  He said that more than a few times the cars were up and running and resold the same week car after a thorough steam cleaning and "secret" tweaks to the engine which was all done after hours when the staff went home.  His "secret" that he didn't openly share with his staff was the injector tester/cleaner that he kept at home. 

That's very amusing.  I'm probably going to take the injectors out of my 2 other cars and clean them and test them.

I think this thread is useful to the community in general, I will ask to have it moved out of the for sale area as that aspect is no longer relevant.

[Jowe]

Indeed 

[scoot]

Just to provide a little context (since this topic was originally in a for sale post that provided context) the discussion is on a "pop" cleaner/tester for mechanical fuel injection injectors like we have in our Pagodas and other MB cars...

Video of what we are talking about can be seen here:
https://www.youtube.com/watch?v=za-5sW2QOIo
and here:
https://www.youtube.com/watch?v=Fb3fHKiVF4o

And the kit can be bought there as well.
Picture attached is from my patio table cleaning the injectors from my M189 engine in my 65 300SE lang.

Scott

[tel76]

Scoot,
Would I be correct in assuming that the pump in your picture is a hydraulic jack?

[rutger kohler]

I also recently tested and cleaned my injectors.  Andy Burns gave me a tester he had bought (thanks Andy) that was made for testng diesel injectors, pretty much the same setup but a much higher pressure gauge which I changed for one with a 400 psi top range.

I also found it better to test all with diesel then clean with carb cleaner, then pump all through with diesel again.  My top range was also between 190 and 200 psi which i put down to older injectors rather than the 230 psi that Kent Bergsma achieved in his video. I made a air blower out of an old air duster gun and a 1/8" nylon tube which I blew each injector out with as in the video.

I also went straight to the water bottle to spray the injectors into, making a hole in the lid a snug fit on the snub end of the injector, which worked brilliantly. Didn't bother with Kents final idea of discharging into a tube.  As the water bottle became 1/3 full I poured the contents back into the tester reservoir through a lab filter paper.  very econmical!


 Lacking the star wars tool provided in the Kent kit I opened each injector with a fingernail and then inserted the end of a small nylon electrical tie as someone else did in an earlier post. Rotated this round the seat several times which seemed to work. All the injectors "chirped" before i finished and appeared to atomise.

[scoot]

Scoot,
Would I be correct in assuming that the pump in your picture is a hydraulic jack?

It's made from that type of component but I'm not sure exactly how.  There are threads on forums about "build your own pop tester".  I bought mine as a kit from MercedesSource.  There are also lots available on eBay, I think all from India.   For the price, I went for the one from MercedesSource since he has a reputation to protect and overseas ebay sellers do not.

[scoot]

I also recently tested and cleaned my injectors.  Andy Burns gave me a tester he had bought (thanks Andy) that was made for testng diesel injectors, pretty much the same setup but a much higher pressure gauge which I changed for one with a 400 psi top range.

I actually opted to buy both gauges (600 PSI and 5000 PSI) with the device.  I don't know if I'll ever use the high pressure one as it was not needed for my purposes, but I have it in case...

I also found it better to test all with diesel then clean with carb cleaner, then pump all through with diesel again.

I'm curious as to why you followed-up with another round of diesel...

  My top range was also between 190 and 200 psi which i put down to older injectors rather than the 230 psi that Kent Bergsma achieved in his video. I made a air blower out of an old air duster gun and a 1/8" nylon tube which I blew each injector out with as in the video.

I also went straight to the water bottle to spray the injectors into, making a hole in the lid a snug fit on the snub end of the injector, which worked brilliantly. Didn't bother with Kents final idea of discharging into a tube.  As the water bottle became 1/3 full I poured the contents back into the tester reservoir through a lab filter paper.  very econmical!

I didn't even bother with cutting a hole in the gatoraid bottle.  I just used a 1 liter diet coke bottle.  The amount of atomization that came out the opening didn't bother me - I was outdoors.  I agree that the long discharge tube is unnecessary.  I think he shows it for liability reasons.  I also didn't bother with the air gun as I thought that spraying carb cleaner with the little tube on the carb cleaner can allowed for agitation of anything stuck in the filter and the opportunity for it to drip back out of the entrance.  As for Kent's little brass tool, it was somewhat useful but I can see achieving the same effect with a fingernail.   I got good chirps at 230ish PSI out of all of my M189 injectors.  And they all started out like crap, but they were from a car that had sat for 10+ years...

[rutger kohler]

Hi scoot, I added a round of diesel after the carb clean figuring it would be better for a small amount of diesel to spray into the engine than car clean (although a very small amount) and also it flushed the carb clean out of the tester at the same time. I didn't use the tube for the same resons as you.  I used the screwtop on the top of the drink bottle because the neat fit meant one less thing to hold!

[scoot]

Hi scoot, I added a round of diesel after the carb clean figuring it would be better for a small amount of diesel to spray into the engine than carb cleaner (although a very small amount)

Yeah, I wondered about flushing it with alcohol but decided it was good enough and that gas would be run through it soon enough.

[watson2]

Scoot,
Would I be correct in assuming that the pump in your picture is a hydraulic jack?

Yes, Eric. I made my one in a similar way, copying a device described in a peachpart forum.
And here I made a video to show how it can work.
 
https://www.youtube.com/watch?v=PLe75LDLP38

I recovered, at this moment, 5 of 7 injectors I have.

Useful

[wwheeler]

I bought the AG precision for good price and shipping was only $15 from India via DHL. On top of that, it arrived 4 days after I ordered it. Amazing!

So my question is concerning carb cleaner. I would think that it would be too hard on the internal test pump seals and such. Alcohol I could see a being mild enough. Also instead of straight diesel fuel, would you instead use an additive that you put in diesel designed to clean injectors?

I will use this on both the 280SE injectors and the old 220SE 2 plunger pump type injectors.

[scoot]

I bought the AG precision for good price and shipping was only $15 from India via DHL. On top of that, it arrived 4 days after I ordered it. Amazing!

So my question is concerning carb cleaner. I would think that it would be too hard on the internal test pump seals and such.

It's amazing how fast some items arrive from India and China -- they really have their bulk shipping to the United States done well.

Concerning the carb cleaner in the tester - Kent says to flush the thing with diesel afterwards for that reason.  Let's see how my pump and yours from India hold up.  I suppose I could always clean more injectors!

Alcohol I could see a being mild enough. Also instead of straight diesel fuel, would you instead use an additive that you put in diesel designed to clean injectors?

I will use this on both the 280SE injectors and the old 220SE 2 plunger pump type injectors.

MY take on it is that Diesel is pretty safe to use on things and makes a good solvent.  But I don't think it is nearly strong enough to get the crap out of injectors if it has lacquered or if there is other gunk in there.  I think that's where the carb cleaner comes into play.  He's experimented with alcohol and thinner and other chemicals.  I think you want it absolutely as toxic as you can get, which is difficult in California because so many chemicals (like Toluene   for example) can't easily be purchased, but if you look on the ingredients of carb cleaner that's pretty high on the list.

Scott

[wwheeler]

So maybe if the injectors are not gummed up and you just want to do a flush every few years, maybe mineral spirts would be strong enough yet not too harsh on the pump?

From an investment standpoint I suppose if the injectors are clogged, you would do whatever it takes to get them clean at the expense of the tester. Afterall, (1) tester is about the price of (1) six plunger pump type injector. The earlier 2 plunger pump type injectors are many times that cost if available at all.  

[66andBlue]

I bought the AG precision for good price and shipping was only $15 from India via DHL. On top of that, it arrived 4 days after I ordered it. Amazing!
...

Hi Wallace,
what is the "AG precision" ??

[scoot]

So maybe if the injectors are not gummed up and you just want to do a flush every few years, maybe mineral spirts would be strong enough yet not too harsh on the pump?

From an investment standpoint I suppose if the injectors are clogged, you would do whatever it takes to get them clean at the expense of the tester. Afterall, (1) tester is about the price of (1) six plunger pump type injector. The earlier 2 plunger pump type injectors are many times that cost if available at all.  

I think if the car is running well and driven regularly that cleaning the injectors is probably not needed, but I couldn't say for sure.   The price on an injector for an M189 engine is around $3000.   I got all 6 of mine to work well (at least on the test bench).

Scott

[Bonnyboy]

Up here in Canda we still can get Toluene.  Would that be a good solvent to use for the injectors or is it too much just on its own.  I would then chase with diesel so I don't damage the tester mechanism?

[scoot]

Up here in Canda we still can get Toluene.  Would that be a good solvent to use for the injectors or is it too much just on its own.  I would then chase with diesel so I don't damage the tester mechanism?

It was recommended to me for cleaning injectors, your mileage may vary.  Kent Bergma recommends flushing the cleaner/tester with diesel after use.

[Benz Dr.]

I think if the car is running well and driven regularly that cleaning the injectors is probably not needed, but I couldn't say for sure.   The price on an injector for an M189 engine is around $3000.   I got all 6 of mine to work well (at least on the test bench).

Scott

I have a box full of NOS injectors for 300SE's. I would take less than 3K for a whole set of them.

[scoot]

I have a box full of NOS injectors for 300SE's. I would take less than 3K for a whole set of them.

Well I seem to not need them, but out of curiosity....   how much for an injector?   You could probably sell them to the Classic Center...

[wwheeler]

Hi Wallace,
what is the "AG precision" ??

Alfred,

Here is the link. http://www.ebay.com/itm/Diesel-Injector-Nozzle-Tester-Pop-Pressure-Tester-Dual-Scale-Bar-PSI-Gauge-/321126672878

It has the higher pressure gauge for diesel injectors. You could always switch gauges easily.
 

[scoot]

It has the higher pressure gauge for diesel injectors. You could always switch gauges easily.

The one I bought from MercedesSource is the same sort of thing, and I bought it with both gauges in case I ever want to use it with a diesel injector.