Fuel injector o-ring replacement (first timer) - help

[HFR_Racer]

I created this problem myself. While changing my spark plugs I rotated a couple of the fuel injectors to make more clearance for my arms. After re-starting my 86 911 I smelled raw fuel. I've traced the leak to the injector o-rings on the #4 cylinder.

What is interesting to me is it appears to be pushing fuel out from the manifold side of the injector. I'm pretty sure that it's not leaking from the fuel rail seal.

My questions is do I simply need to follow the instructions shown here in this tech article? Pelican Technical Article: 944 Fuel Injector Clean & Reseal.

I wasn't going to test the injectors since my vehicle only has 57k miles and runs fine. I only plan to replace the o-rings on the injectors.

I am also looking for an other advice from my fellow Pelicans before I start this project.

This seems to be an easy project for a mechanical person.. Is it really??
Do all of the needed seals come in a standard injector seal replacement kit? ie. injector to rail and to the manifold. How many seals (o-rings) are used at each injector?

Thanks in advance....

[jbrinkley]

if you need some orings I have a buch in little bags from pelican, just sitting here. PM your address and I'll send some to you N/C
Are you sure you got tham seated all the way? I had problems when I did mine, it took a couple times to get everything lined up right, and all the way down in there

[HFR_Racer]

Thank Jerry but I already have the o-ring sets.

Now I have another couple of questions. When I re-install the injectors is it a problem if I route the injector wiring between the manifold and the injector rail? Currently all of my injector wiring connectors point to the outside of the vehicle.



Next question... What is the regulator looking parts at the front of each fuel rail. What exactly does this do. I can see that it is vacuum actuated. My vacuum line connection to this regulator is very loose. Is this a problem?

[jbrinkley]

I think, trying to anyway, that number 4 and number 6 have to point toword the wheel, The connectors I mean. I don't think it matters where you run the harness. Just a matter of not messing up the wires with a kink.
I saw someone answered the other question

[mackskibum]

I haven't had the injectors out of the manifold yet, but it would be unlikely the fuel would be coming up from the manifold The most likely place would be the o-ring at the fuel rail unless the injector body itself is leaking. If correctly installed, the nozzle end sould be buried too far into the manifold to leak out.

[HFR_Racer]

Assuming that the injector body is cracked. How can I inspect for this at home?

The fuel that I saw on the manifold at the #4 injector evaporated overnight. The leak is definitely at the #4 injector ( guess it could be leaking from the injector/fuel rail connection) but I don't think so. I'll replace the O-rings first and if that doesn't fix it I'll be looking for a cracked injector body.

[Jesset100]

[mackskibum]

I am not suggesting that the injector is actually cracked- but if you look at a Bosch injector, it is not one piece- a leak could be at the interface between the plastic electrical/ fuel interface and the steel body for example. I would suggest pressurizing the fuel system by jumping the fuse panel to start the fuel pump with the engine not running, and ignition off. This will pressurize the fuel rail and allow you to inspect for the leak without exposing the leaking fuel to a running engine. You could also connect a fuel pressure gauge at this point and check for pressure leakdown.

[HFR_Racer]

Fellow Pelican's.. I found the leak at the interface between the main injector body and the nozzle body. This explains why I was seeing fuel on my intake manifold. The leak was above the O-ring seal for the injector to the manifold. See photo:



I was able to rotate the injector body independently of the nozzle body. New Bosch injector ordered for Tuesday morning installation.

[mackskibum]

Glad you found the problem!

[HFR_Racer]

All is well.. My fuel injectors have new O-rings and are installed plus a new injector for cylinder #4. Best of all, it started with no problems. I'll be on a test drive tomorrow.

Yippie.. It's supposed to be 50 degrees tomorrow in Indiana.

[dfink]

Yes I know search. I have done that.
When replacing injector seals the kit comes with 3 o-rings 1 fiber ring and 1 plastic cap. What all do you replace. I thought my o-rings would be hard but they aren't so I don't know why they were leaking after being down for a rebuild. But anyhow.
Do I just put on the o-rings and leave the rest.
Do the little plastic caps just pop off and get replaced along with the fiber.
I have seen posts where it says just use the o-ring I am confused.
[edit] sorry meant to do a new thread......