Fuel injector install

[Wew]

Hey all,


Started my first fuel injector install. New lines injectors rubber sleeve housings, little black rubber seal and the o ring seal. I put it all in and it makes that nice little pop sound when it seats. It just seems the sleeve housing still sits up a little high. When I compare to the old ones that sit flush in the housing. I get a little play and can pull out with a firm tug. Reseated and hear the nice pop again. Tried seating deeper but that is as far and deep it wants to go. Am I good or am I missing something in the install process?
Top photo is new injector and second one is an original.
Thanks all for your help,

Gary
911 sc california targa 1978

[Cooper911SC]

The plastic injector sleeves are actually staked into the manifold.

Look for a small squareish stake mark in the edge of the aluminum. You may need to smooth the old one off with a file, install new sleeve and then re-stake.

I encountered this on my '81 SC

Cooper

[James Brown]

yep the "nibs" in the manifolds need to be blended out to seat the insulators

[47silver]

They need to be below the edge. Pull one out you will see nubs that were bent. I used a punch to seal mine

[Wew]

Ok thanks for the information. What did you use to set them or punch / push them down in the housing?

Thanks,

Gary

[47silver]

you have to ream the inside of the manifolds to get the bores smooth so that the injector goes in easily. then you get a punch and lightly bend over some of the manifold (
some people don't stake them
injector sleeve install how to make bungs

[Wew]

Guys,

Sorry for me not being able to connect the dots on this one. I am just not getting what where these "nibs" are?

The entire sleeve has come out of injection port 4. I have put a new sleeve and seal and o ring on the injector.

I slide the sleeve into the port. No problem, except that it will not seat flush with the housing.

If we could dumb down the terminology for a moment...
Do I simply find a tap that is the same circumference as the opening of the sleeve and tap it down until it sits flush?

then simply push the injector in with the big doughnut ring attached until I hear the pop sound?

Sorry for being confused but reading about tamping and nibs and putting a marks on the housing just is not making sense to me. The way I am seeing it currently is those little marks on the housing do not accomplish anything is simply a scar on the housing based on someone pounding the sleeves into the port...

This could be part of the confusion and mis understanding... Is there another part or component or little washer that sits on the top housing that is popped off and then pounded back on after the sleeve is installed.

Still many questions.

p.s. I tried a mobile mechanic to get a quote in my area to do this job for me since I am running into a little trouble. $900 was his quote for the job to install the injectors and do an air fuel mixture after wards. (NO PARTS, just labor) Wow! I said thanks but no thanks. Every long hour I spend on this car is not only fun and rewarding but truly saving loads of cash to folks out there that really seem like they want to gouge you as well.

Many thanks in advance,

Gary

[47silver]

at 4 oclock and 7 oclock are notches, that is where the aluminum had or has been bent over to hold in the sleeves,, if yours is gone then they may have been replaced, but notice how low the sleeve is in the bore.

[Cooper911SC]

Hi Gary, I'll take a stab at helping to clarify.

First, just for a reality check, look at the length of your new and old sleeves.

As far as the fit goes, when the aluminum manifold was brand new at Porsche it just had a round hole in it.
The assembler took the plastic sleeve and slip fit it into the manifold. It is not a super tight fit, just snug.
Next it was necessary to use a small chisel or punch to dimple or deform the AL. manifold hole. Now you have a round hole with sharp stake mark in it. This way the injector sleeve can not easily back out of the hole.

What happens over the years is that the plastic sleeves degrade from heat cycling, engine fluids etc. and become loose in the hole.

The injector O rings also get hard. When you try to pull the injectors often times the sleeve will come too.

You will see a scoring mark on the plastic where it scraped past the stake mark.


What you need to do is disassemble as you have.

Next, take a reamer or small round file and make the hole in the AL. manifold round again.
It shouldn't take much work at all to smooth off the little dimple.

Next take your new sleeve with the new O ring installed on it, apply a light coating of silicone grease to the O ring and push the sleeve into the manifold.
It may help to use a small socket or round dowel matching the OD of the sleeve to push with.

Finally use a small cold chisel or flat blade screwdriver and gently re-stake the edge of the manifold.

When installing the injectors into the sleeves silicone grease will help too.

My guess is that the old stake mark is hanging up on the sleeve O ring keeping it from seating.

It may also be that installing a new "dry" O ring is causing the O ring to stick or hang up slightly on the ID of the AL. manifold.

I hope this helps clarify things for you Gary.
You'll get them installed!

Take care, Cooper

[theiceman]

i used a dremmel on mine with a very fine grinder tip to remove the tamping mark before i took mine out, that way the shavings stay on the outside, blew it all off with my comressor .. , then proceeded as above. When done i "tamped" it with a cold chisel . One gentle tap per injector is all it took.

make sure you have the right sleeves to start with though .

[Wew]

O.K. Thanks a bunch for the detailed explanations. Much appreciated.
My next question is should I just go for it and remove the entire CIS from the motor to accomplish this or is it possible to do still installed?
Don't want to wrestle with it if removal allows me easier work space long run and allows me to potentially address any other issue with the motor.
Although I must admit I do have while you are in there idis.
Thanks a bunch again.
Everything I have learned from all of you has been invaluable.
Gary

[timmy2]

Partial drop and pull the CIS system, will be easier in the long run and reduce rhe chance of dropping anything into the intake like broken o-rings or pieces of the runners...
I've pulled it in under 2 hours this way. There's a reason the guy wanted to charge you 9 hours labor. It would take me about 5-6 hours from start to finish to do the job on my '78 if I still had CIS. Now it takes about 20 minutes to pull the intake with the Bitz kit!