injector opinions

[merrill]

hello, sent my inj pump off to hans for rebuild ($950) and check the injectors.

3 of the 6 are bad.  he did not recommend the new injectors ending in R2 but suggested I find 3 old injectors ending in R1.

any opinions?
hans said if I cannot find old r1's I can get 3 new r2's to complete the set of 6.

I can get new R2's for 90 bucks each at arizona autohaus.  

matt

Matt
Austin Tx
66 230 sl - "white"
78 300 D - Blue
98 C230

[mbzse]

quote:Originally posted by merrill

...check the injectors.../.. recommend the new injectors ending in R2 but suggested I find 3 old injectors ending in R1.
any opinions?

Mercedes warn against mixing R1 and R2 type injectors in one engine. Thus, to try to find three R1 (might prove hard, not been manufactured for many many years) or change over to all R2 seem to be the alternatives open to you.

/Hans in Sweden

[DavidBrough]

This site never ceases to amaze me with the useful information you can gain. Thanks Hans.

I had to replace 3 of my injectors about a year ago and duly did so courtesy of SLS and thought no more about it. The guy that cleaned my old ones thought they were the originals so presumably they are R1’s and the new ones must be R2’s.

Does anyone know why they should not be mixed and what the likely problems might be. I hope the issue is just rough/uneven running or could I have damaged something already?


David Brough
1969 280SL

[DavidBrough]

Can't believe I managed to reach 99 so I just had to make it 100!

David Brough
1969 280SL

[ted280sl]

David,
  Living in New York I had the pleasure of meeting with Hans. He told me he likes the R-1's because they can be rebuilt. I understand they are very hard to find. My car came with r-2's. I replaced some of my injectors with new r-2's then a few more of them went bad. It seems that it is not a bad idea to replace all of them. I believe they were only $60 each a few years ago.
Regards,
Ted 1969 280SL

[DavidBrough]

Thanks Ted,

I suppose I am better off replacing them all, I didn’t do at the time as they are 101 Euros each now. Still, doing another three at this stage is not so bad.

I assume any symptoms of mixed injectors would just be the possibility of rough/uneven running.


David Brough
1969 280SL

[ted280sl]

David,
  When an injector goes bad rather than atomizing the gas it sprays the gas as a liquid. It is my understand that a bad injector will have  greater impact than merely a rough running engine. I believe the liquid gasloline in the combustion chamber will dilute your cylinder lubrication and will lead to premature ring damage. This scared me enough to part with the money to replace all of my injectors.
regards,
Ted 1969 280SL

[merrill]

Ted,
so, how does one tell if an injector is bad?  without removing it and testing it?

matt

Matt
Austin Tx
66 230 sl - "white"
78 300 D - Blue
98 C230

[Cees Klumper]

Specialized shops will have a tester that is not a very high-tech instrument: the injector is taken out of the engine and is hooked up to the tester; pressure is applied with a manual handle to force gasoline from a canister through the injector. The pressure needed to open up the injector can be read (it should be xx PSI at a minimum) and then the spray pattern of the gasoline can be viewed.

Here is an image of such a device:


Download Attachment: tester.jpg
37.64 KB

Cees ("Case") Klumper in Amsterdam
'69 white 280 SL automatic

[DavidAPease]

Cees and Merrill,

Here is a photo of another, more technologically advanced injector tester:  

http://www.sl113.org/forums/uploaded/ja17/200582201223_Blacklick%20Injection%20Pump%20Test%20Bench.JPG

Courtesy of Joe A!

-David Pease
'66 French 230SL