Replaced my CIS Injectors today

[MPDano]

I thought I would share my project today. I replaced my tired 29 year old injectors with the Mercedes ones recommended by so many out there. I also bought a new set of seals, eventhough the ones I had were less than a year old. I didn't want to chance it, plus they are inexpensive too. I ended up cracking one of my Collars, but luckily RJM65 lives a couple miles from me and also drives a CIS 928 and he just happened to have a few good ones from his MB Injector changout last week.

I used Silicone on the Seals and Anti-Seize on the Collar and Injector Threads

[MPDano]

[MPDano]

Cracked Collar

[MPDano]

Here's a quick video I shot too.

[rhjames]

very nice, Leo.

did you rework the steel lines as well?

--R

[MPDano]

Originally Posted by rhjames

very nice, Leo.

did you rework the steel lines as well?

--R

I sure did Russ! I used a very expensive Harbor Freight Wire Brush to clean them off

[Fabio421]

Why are you using those injectors? Are the original style injectors not available? It seems that the spray tip will be severely shrouded with this shorter injector.

[MPDano]

Originally Posted by Fabio421

Why are you using those injectors? Are the original style injectors not available? It seems that the spray tip will be severely shrouded with this shorter injector.

A less expensive alternative and lot's of positive user experience. I used to have a slight miss and it's totally gone. $20 vs $35 per Injector was big decision maker for me. Originals are still available.

[rhjames]

Originally Posted by MPDano

I sure did Russ! I used a very expensive Harbor Freight Wire Brush to clean them off

that wasn't quite what I was referring to....

reworking the line ends:

using emory cloth, make sure the line end (each end, each line) is smooth and not deformed.

using a small drill bit, carefully drill out (open) the holes on each end of the line. start with a bit size that is just larger than one that will fit in the hole, and gradually work towards a larger size. be extremely careful to not let the bit get jammed in the line, or punch thru the line itself.

why is this important? you are making sure that each hole in each line is equally the same size. it does make a difference. each cylinder will be making the same power as the rest--as far as the fuel system is concerned.

this makes a huge difference on mechanical pump diesels (ex: Caterpillar), which use the same constant injections fuel systems---the same as your CIS on your P-car. the type of fuel used is of no importance, gas or diesel, the principle is the same.

I have done this myself on my Euro and Dad's US spec, in addition to the 047 injectors with great success.

--R

[rhjames]

Originally Posted by Fabio421

Why are you using those injectors? Are the original style injectors not available? It seems that the spray tip will be severely shrouded with this shorter injector.

Cost Fab.....

$20 bucks for the 047 , $80 + for the OEM 928 units .

I actually bought an entire set of 047's for $56 delivered.....

--R

[hitman3]

me 2 change them all the work nice

[ROG100]

With the injector nozzle being much shorter than the original does this not affect the spray pattern??
How well do they work? Any loss in power? What about MPG any increase or decrease?
The old ones look pretty bad so anything would be better.
Like the idea but want some hard facts before I offer tham as an alternative.
Thanks for the info.

[ROG100]

The only direct replacement that I have seen is the 0437502012

[DPW928]

Nice job Leo.

Roger, I've always thought the stock injectors went too far into the intake to get an even distribution of the fuel vapor. My next set for the 928 and 931 will be the MB units.

[MPDano]

Originally Posted by DPW928

Nice job Leo.

Roger, I've always thought the stock injectors went too far into the intake to get an even distribution of the fuel vapor. My next set for the 928 and 931 will be the MB units.

A few of us CIS guys have been using them (Benz Injectors) now with zero issues to report. Glad this topic helped you in your decision.

[ROG100]

Zero issues sounds good but any data to back it up?
The other direct alternative is a Benz injector as well so as long as we are not mixing them up.
The idea is great but I need some facts to back it up.
As no one seems to have any I may fit a set to one of my cars and do some testing so that I can offer them as an alternative with a level of confidence.

[MPDano]

Originally Posted by ROG100

Zero issues sounds good but any data to back it up?
The other direct alternative is a Benz injector as well so as long as we are not mixing them up.
The idea is great but I need some facts to back it up.
As no one seems to have any I may fit a set to one of my cars and do some testing so that I can offer them as an alternative with a level of confidence.

Hi Roger. No data just my experience and another local fellow OBer too. Also, a couple more CISers like us here on Pelican that I consider to be reliable sources of info. I think it would be great for a reputable Vendor like yourself to run some personal tests.

I chose them since they were less expensive and have a good reputation.

[Mrmerlin]

FWIW I have fitted these MB injectors to 5 928 CIS machines ,
every one has resulted in excellent running performance.
I know this is an old thread but for anyone searching around today,
these MB injectors work fine.