CIS Injector Question

[MPDano]

I was putting my CIS Injectors back with new seals. When I tighten them down, they get to a point where the injector gets above the sealing ring. Is this right? Out of 8, 2 tightened all the way with no issue, but the other 6 went above the ring, so I just stopped there. Is this tight enough to seal?

[Danglerb]

Leo, try one in your spare intake leg and take a look from the inside, but I suspect it needs to fully seat and something is binding or blocking it.

[rhjames]

Originally Posted by MPDano

I was putting my CIS Injectors back with new seals. When I tighten them down, they get to a point where the injector gets above the sealing ring. Is this right? Out of 8, 2 tightened all the way with no issue, but the other 6 went above the ring, so I just stopped there. Is this tight enough to seal?

Leo-

not sure I understand what you are describing about the injector gets above the sealing ring........

the seal has a rib on the inside. this rib locks into a corresponding groove that is on the injector body.

as you probably know, the seal goes onto the injector (fat end to the top--away from the motor), then the sealing ring goes over the seal with the threaded (injector line connection) portion above the sealing ring. also protruding through the sealing ring would be a portion of the HEX sided part of the injector.


as to how tight you go with the assembly, you will be using a wrench on the injector HEX area to tight this, tight enough to seat the seal but not so tight as to ruin the aluminum sealing ring threads (don't strip them).

did you reuse the original injectors? if so, did you have them sonic-ly cleaned?

hope this helps--

--R

[rhjames]

Leo--

if you are changing injectors but haven't bought any yet, there is a supplier in Arizona that has a Mercedes Benz injector that is a direct replacement, for about $20 per unit.

part number is 0437502047

it is actually a brass unit, said to be much better that the steel ones.

I have a set in my Euro---

******** Arizona--they have a website

--Russ

[MPDano]

Hi Rus,

Yup, the assembly is what you described. Although, as you tighten the the hex (12mm), it get to a point to where the hex is above the sealing ring and begins to turn without tightening the sealing ring. I do stop at that point, but there are a couple rings I can still move by hand.

[Danglerb]

Sounds like stripped threads. How about some pictures of the parts. Maybe a BIG timesert?

[rhjames]

Originally Posted by MPDano

Hi Rus,

Yup, the assembly is what you described. Although, as you tighten the the hex (12mm), it get to a point to where the hex is above the sealing ring and begins to turn without tightening the sealing ring. I do stop at that point, but there are a couple rings I can still move by hand.

could be the threads on the sealing ring/in the intake tube are a little messed up, but I would not force any of this.

Damage to the sealing rings is pretty easy to do----ask me how I know.


--Russ

[MPDano]

I am wondering now if I put the seals on correctly. I put the seal groove towards the engine and not the hex. Will this make a difference? I am sure it's not the intake threads. Is there a washer that went between the sealing ring and intake?

[Danglerb]

http://dcauto.gotdns.com/illustration/index/480619714




34 928.110.399.02 Tensioning sleeve (8 recommended) -79 $10.84

35 928.110.398.00 Sleeve for injector valve (8 recommended) -79 $2.94

[orange9mm]

rhjames,

i am curious about the mb 0437502047 injectors. are you currently running them on your car without any issues, did you notice any changes ( or were your Porsche injectors really bad to start with )? what makes them better, besides the awesome price? is the flow changed or is brass just a better material for this part in terms of longevity? i am about to pull my intake on my car and i am going to replace the runner gaskets, spark plugs, runner boots, clean the metering plate. might as well do the injectors at that price since the runners will be out.

[MPDano]

Yup, I was right. Flipped the seals with the indent facing the injector hex and walla. Tightened up perfectly. Also, a deep 12mm socket works perfectly.

[rhjames]

Originally Posted by MPDano

Yup, I was right. Flipped the seals with the indent facing the injector hex and walla. Tightened up perfectly. Also, a deep 12mm socket works perfectly.

Ah...it's a wonderful thing!

That's what I was trying describe about putting the big end of the seal facing away from the engine/towards the fuel line connection.

Glad you've got it whupped.

--Russ

[MPDano]

Thanks Russ,

I am sure your explanation put subliminal messages in me. Glad this got sorted out as I was at a stopping point again.

[rhjames]

Originally Posted by orange9mm

rhjames,

i am curious about the mb 0437502047 injectors. are you currently running them on your car without any issues, did you notice any changes ( or were your Porsche injectors really bad to start with )? what makes them better, besides the awesome price? is the flow changed or is brass just a better material for this part in terms of longevity? i am about to pull my intake on my car and i am going to replace the runner gaskets, spark plugs, runner boots, clean the metering plate. might as well do the injectors at that price since the runners will be out.

yes, I am using a set in my Euro with huge improvements. (my injectors were in sad shape.....)

I have very little info about them, only what I have read off of the web...It is my understanding that the flow is the same, have no idea if brass is better, but this is supposed to be an updated unit from MB.

--Russ