awilli6

Hey gang, I'm putting the finishing touches on my intake refresh and the fuel rail won't go down enough to allow the injectors to seat fully. Is there a trick to it?

hacker-pschorr

What year?

awilli6

87

MainePorsche

New O-rings ?
I gave a little love tap with a rubber mallet above each injector.

SteveG

Did you lube the O-ring? Anything that gets those buggers fully seated; a little lube and a tap should get the injector into position.

awilli6

I'll give it a try

MainePorsche

I was considering a little lube, but was leery if the heat there would effect the lube residue and compromise the ring. I'm not the MSDS expert on their properties.

UpFixenDerPorsche

BTDT. If there is a layer of manifold paint is in the injector hole then there's insufficient clearance for the injector o-rings.

You need to remove excess paint until the injectors can be firmly pressed in by hand. No hammering.

dr bob

Lube on the o-rings helps them go in without any rolling. Reduces the chances of leaks. They are fuel-proof, so not much risk of them being damaged by a little bit of silicone spray. That's if you don't have any o-ring assembly lube.

Mrmerlin

I suggest to get some Dow Corning 111 and put a smear on each O ring they will stay soft and slide into position.

NOTE that if you dont install the injectors properly you can push the lower side through the manifold seat area,
and thus the top O ring will not be sealed then when fuel is appled there will be a big leak

awilli6

Tried a little oil, No Joy. I'm going to call it quits for the night. I'm getting frustrated & I don't want to break anything

Imo000

Spit on it and push on the rail from the top. Start on one end and work your way to the other.

hacker-pschorr

Did you replace the lower o-rings?

It wouldn't be the first time someone installed new o-rings that were slightly too big.

UpFixenDerPorsche

Awilli6, as I posted earlier, I had this problem when I repainted my S4 manifold.

If there is a layer of paint down in the fuel injector recess then you won't be able seat the injector no matter what you try. Insufficient clearance.

Like you, I was ready to tear my hair out. Then I remembered the injectors fitted OK with the factory paint job. I didn't think a thicker coat of paint could make the difference but it was the only possibility left, and that's what the problem turned out to be.

Get some emery paper, shape it into a cone, and slowly remove paint until the injector can be seated with a very firm push.

You don't have to get to bare metal, just back to the same thickness as the factory paint.

I you don't believe me, just try it on one hole.

awilli6

I did paint the intake so I'll go after the holes a little. I sent the injectors to Witchunter so the rings should be the correct size. Thanks for all of the input.