Fuel injectors

[menesesjesse]

Does anyone know a back yard way of testing the fuel injectors or the approximate cost of checking mine out?  At 100.00 a nozzle new I would rather not buy 6 of these if I can verify their operation at home.  Thanks
Jesse

[Jonny B]

Maybe Joe Alexander can make a special deal with sending his (truly) backyard test rig...if someone has a picture available, it would be good to post it as a piece of Blacklick history.

[Cees Klumper]

Maybe Joe Alexander can make a special deal with sending his (truly) backyard test rig...if someone has a picture available, it would be good to post it as a piece of Blacklick history.

I know Tom Sargeant actually made a digital video of the Blacklick test rig back in 2002. And if I am not mistaken, a photo is in one of the earlier issues of 'Pagoda Notes'.

testing these injectors should not be a big deal at all, AFAIK it takes a minute per injector.

[ja17]

The Blacklick Injection Pump Test Bench

[menesesjesse]

Wow
I think I can do this at my house.  I have 2 injector pumps so I can spare one for the test.  What was used to feed the fuel?  Can I just fill my filter up cap one side and then feed the pump by gravity?  Thanks for the photo.   
Jesse

[mait]

Any diesel shop that can test Bosch injectors can do it. I had mine checked last summer. Spray pattern, tip leakage and fuel atomization all acceptable. Opening pressure even at 10 bar+
Shop charged 0.5 hr of time = $41.25 CDN

[waqas]

Wow
I think I can do this at my house.  I have 2 injector pumps so I can spare one for the test.  What was used to feed the fuel?  Can I just fill my filter up cap one side and then feed the pump by gravity?  Thanks for the photo.   
Jesse

Jesse,
I had the honor of pumping this work of art at the last PUB ('07), and yes, it is gravity fed from an old fuel filter canister. It is incredibly easy to set this up at home if you've a spare injection pump. Also, be sure to use diesel instead of petrol to reduce the danger somewhat.

[menesesjesse]

Well I was looking at the injectors and I noticed that 4 had R1 and 2 of them had R2 at the end of them.  The R2 injectors even look bigger internally.  What is the best injector to use for the 230.  My M/B manual says not to interchange them but they are used on 230/250sl motors  I am curious about the differences.  Does anyone know?  Thanks
Jesse

[merrill]

Jesse
Hans at H&R explained this to me once, lets see if I remember correctly

R1 - more like a diesel injector where at pressure the fuel is released via spring loaded action into the nozzle

R2 -   imagine a metal ball suspended in a tube.  when the pressure is released the pressure flows down and the metal ball causes the spray.

I could be wrong but I think this is what hans told me.

Matt

[jameshoward]

Mait's advice is spot on. Go to any decent diesel place and they'll test and clean for very little money.

[waqas]

Yes, Matt's description is correct.

In addition, the R1 type with the conical shaped seat came in early cars, whilst the R2 type with a ball shaped seat came in later cars. I remember reading an old post where it was mentioned that the old R1 conical seated injectors provided a more uniform spray pattern, and were hence preferred over the later R2 type with the ball seat.

[jacovdw]

Also the R1 injectors are no longer available.

I have recently bought a set of 6 new R2 injectors for my 230SL and have had no problems at all.
Funnily enough, according to the service manual, the opening pressures are the same for both R1 and R2 injectors.

[menesesjesse]

Well I found a way to test the injectors without a huge setup.  I had a a hyrdraulic shop make up a high pressure hose with adaptors to fit the injector.  I simply set it up to a sealed grease gun and pumped kerosene through them to clean them and check for a nice spray pattern.  I took the best 6 I had.  The R2's seemed to squirt more based on what I saw.  The R1's misted in a conical pattern nicely.  The setup and testing took me 1hr total to test all of them twice.  I realized I didnt see the amount of pressure it took to get them working but I can always get a guage with a T off to verify the pressure.  I hope this may help others out there like me looking to do things at home.  The hose cost 25 bucks to make if anyone is interested in getting one made.  Thanks
Jesse