How to remove injectors from intake runners (CIS)?

Porsche-O-Phile · Porsche-O-Phile's Garage

I'm in the process of cleaning up my CIS intake runners (pipes) and I would like to yank the injectors out so I can better clean them up. I have all the intake pipes off the car but the injectors are still tightly installed in each. Rotating the hex nut on the top portion does nothing (the injector just spins around - the hex nut is only for the fuel line fitting that feeds it). Am I missing something? How do I extract these injectors without forcing or breaking them? Probably an obvious/stupid question but I also don't want to damage anything on these (they're expensive to replace).

TIA.

Al S · 12-16-2007, 11:10 PM

Just gotta yank hard on them, but if you have plastic fuel lines, don't yank on the line.

psalt · 12-17-2007, 03:23 AM

Jeff,

It takes a lot of force to pull them out. Sometimes the injector sleeves will pull out over the stakes and they will be ruined. If the O rings on the sleeves are original, they will be baked and need to be replaced. Grind off the stakes before you pull the injectors, remove the sleeves, replace both o rings and restake.

Porsche-O-Phile · Porsche-O-Phile's Garage

Thanks, I already removed all the fuel lines so nothing to worry about there. I suspect everything on them is original so if there are seals or whatever in there that require replacement, I guess that's okay (probably about time they were replaced anyway).

Any way to test the injectors? Witchhunter's web site says they don't do CIS injectors.

What do you mean "grind off the stakes"? Huh?

psalt · 12-17-2007, 05:47 AM

What do you mean "grind off the stakes"? Huh?

Take a look at the parts diagram. The injectors are not mounted directly to the manifold runners. There is a plastic sleeve insert in the runner that insulates the injector. Porsche chose to stake (deform the aluminum with a punch) these in place, unlike other CIS applications where they are threaded in. There is an O ring on the injector to seal it from the sleeve and an O ring on the sleeve to seal it from the manifold runner. The injectors seals are usually in better shape because they are insulated, the sleeve O rings are usually baked. If you yank on the injectors you can pull out the sleeves over the stakes and destroy them. The correct way to do this job is to first grind off the stakes with a dremel tool, remove the sleeve, then remove the injector. Otherwise you will be buying some new sleeves.

Porsche-O-Phile · Porsche-O-Phile's Garage

OK that makes sense I think. Looking down at the injector from above you can see three depressions (the stakes, I'm guessing) around the perimeter of the injector itself. I wasn't sure if these were part of the intake itself or some sort of pressed-in retainer ring, possibly threaded (I couldn't see threads on the inside of the depression in the intake though, so that's why I was wondering).

I cannot see any evidence of plastic sleeves at all either above or below the plane of the deck. I'll take some pics later today. I'm wondering if my setup was missing a few parts?

Car did run okay before I took all this stuff apart, but I also want it to be correct.

Porsche-O-Phile · Porsche-O-Phile's Garage

Here are the pics - am I missing the plastic pieces you're talking about? Sure looks like it from the parts diagrams. . .

Is this the sleeve?

1982911SCTarga · 12-17-2007, 08:04 AM

Your runners have the sleeves. You can see the sleeve in the pics both in the top and bottom view.

I removed my injectors by attaching a section of fuel line to the injector. Then I use a smaller wrench to pry against the line fitting (it fits around the injector but not the fitting on top). I use the handle of yet another wrench so that you're basically prying the injector gently straight out.

Brian

Zeke · 12-17-2007, 08:08 AM

You don't need witchhunter. Soak the tips in Berryman's.

Scott R · Scott R's Garage

That's the sleeve, get six new ones now, and o-rings. They will probably crumble when you remove them. I get about 50% of them out when I pull old injectors, the other 50% crack, or some out in pieces with the injector.

1982911SCTarga · 12-17-2007, 08:14 AM

Quote:

Any way to test the injectors? Witchhunter's web site says they don't do CIS injectors.

Like Milt says, I'm planning to pressurize mine with air and run Berryman's through them as part of my poor person's DIY cleaning and flow-checking.

Brian

dtw · 12-17-2007, 08:28 AM

I just tap the injectors out from the bottom with a soft rubber mallet. For the sleeves, I tap a slightly oversized drill bit into the sleeve and then whack the sleeves out with a hammer. This obviously destroys the sleeves but as you'll see, they'll be ripe for replacement.

Before even testing injectors, I usually soak them in solvent for several days. Throw them in an ultrasonic cleaner if you can get your hands on one.

911quest · 12-17-2007, 08:32 AM

This is what I use it is for watercooled cars but works on 911 also.

http://www.toolsource.com/fuel-injector-puller-volkswagen-porsche-audi-p-58847.html?sourceid=froogle

psalt · 12-17-2007, 08:43 AM

Jeff,

Yes, you are pointing at the bottom of the sleeve. The stakes are the rectangular depressions on the top edge of the runner. You have to grind or cut them off to fit the sleeves. It is just much smarter to cut them off before attempting to remove the injector.

Porsche-O-Phile · Porsche-O-Phile's Garage

Cool, thanks for the advice guys. New sleeves & o-rings ordered. I'm sure the old ones are probably a bit. . . um. . . crusty & brittle. Like my underwear after a week or so.

Jay Laifman · 12-17-2007, 10:27 AM

On mine, a 73.5, the size of the nut on the injector is smaller than the one for the tube to attach to the injector. I take the open end wrench for the smaller injector and put it on to the injector, then use a block or other wrench to use as a fulcrum to push on the wrench and pry the injector up and out. The biggest problem is getting that fulcrum located so that it doesn't bend anything.

Obviously, you'd have to put the tube nut back on for this. It also may have been easier with them still attached to the head.

They make a tool that basically does the same thing. I've never bothered to buy one. It's like a claw that hooks under that same tube nut, and it has holes in it to put through a screwdriver to, again, pry it out.

Porsche-O-Phile · Porsche-O-Phile's Garage

Finally got the injectors out and they're soaking in solvent now. I was able to tap them out without grinding anything, although the sleeves are still in place. So my last few questions:

1. Assuming I grind off the stakes, how do I secure the new sleeves? I suppose I could get a punch and smash in new ones, but this seems a bit crude. . .

2. What's the best way to test the injectors? Just crank the car with the injector out and see if it sprays?

Thanks in advance, sorry for the naive questions - this is just a very weird setup that I'm not at all familiar with and I don't want to do something wrong/stupid and end up with a fuel leak or something.

psalt · 12-26-2007, 07:23 AM

1. Assuming I grind off the stakes, how do I secure the new sleeves? I suppose I could get a punch and smash in new ones, but this seems a bit crude. . .

Jeff,

The sleeve O rings are the most important thing to replace. Yes, grind off the stakes with a dremel and the old ones slide right out. Make sure the edge of the hole is deburred. Lubricate the O ring, slide in the new sleeve and make three new stakes with a flat punch in three new spots. Crude yes, but all Porsche.

My advice is to get new injectors and you will be good for another 33 years. In addition to the spray pattern, old injectors often leak pressure, causing several problems with CIS.

Mike Andrew · 12-26-2007, 09:09 AM

Damn, I was going to post the same question today as I just received 6 new sleeves & O rings this morning. Looks like the punch & I will be busy tonight.