pauldvazquez

I proactively replaced the original fuel lines (all three) on my 1986 944 NA (September 1985 build date), which I have owned a little over a year. Upon completion of the replacement I checked for leaks and was happy to see my plumbing connections completely dry. I took the car around the block and opened the hood to check again, noticing the smell of gasoline. All the plumbing connections were dry, but the front inject was leaking! It had never leaked before. As a matter of fact, during my ownership, the car had never had a fuel leak.

Okay, I thought, reseal time. What could go wrong?

Then I read the multitude of injector seal threads. Mmmm, it seemed that this project could maybe not go well.....and it hasn't. Instead of the front injector leaking, which was the original problem, now the rear most two injectors will not seal

I tried to apply all the "tips", making sure to have all the o-rings well lubed, making sure the pintle cover was snapped completely in place, assuring the injector clips were properly installed before re-installing the fuel rail. I tried installing the injectors into the intake manifold then the fuel rail. I started off with the Rennbay kit, then the Bosch kit, then the Echlin kit.....all with the result of no dice.

What the hell?!!! How could this be such a train wreck? I am pretty sure I am not the sharpest tool in the tool shed, but I have performed much more complex and detailed tasks than this and have never experienced anything as perplexing and, to be honest, downright stoooopid as what I am involved with now. How could anyone trust these things to not go up in a big fireball at any minute while either on a grocery run or on the freeway at 70 MPH?

After reading all the previous threads I don't know if there is anything further to offer as advice, but I would sure appreciate some current advice as to how to proceed from here.

Thank you,

tempest411

I'd be willing to bet that where the seal needs to seal is pitted. I'd pull the rail and take it to a machine shop and see if they can hone it out for you. Or, maybe just cleaning it up with some 600 grit wet/dry sandpaper would work. Just make sure you blow it out real well!

pauldvazquez

I appreciate the quick reply. I should have included the location of the leak. The injectors are leaking at the manifold/injector joints. The rear two leak and the front two are dry as a bone.

royalschwarz

Take the rail off and clean out the manifold holes. On more than one occasion I have found bits of dried out o-rings stuck to the aluminum. You don't want to mar the surface of the aluminum but I'm willing to bet there is dried rubber down there preventing the new o-rings from making a good seal. Get a strong flashlight and shine down into the holes and make sure they are completely clean.

Also double and triple check that the pintle caps are indeed snapped all the way down. The point of the injector should stick a bit out of the cap. Again, learned the hard way on more than one occasion. Some of the kits out there really need to be pushed on hard to get it to snap all the way. It almost feels like you're going to break the things to get them on but once you get it on, it's on.

pauldvazquez

Royal,

I cleaned the intake manifold injector ports all three times. The first two tries apparently they weren't immaculate. On the 3rd try, they were clean as a whistle. Carb cleaner soaked cotton swabs scrubbing the port surfaces, while running a vacuum cleaner over the port. I cleaned them until the cotton swabs no longer changed color, like both ends of each swab, 6 at each port.

michael7810

I've had the injector itself leak on 2 occasions. Had to pull the rail with injectors installed and pressurize to see the leak. This happened after I resealed the non leaking injectors for " peace of mind" while replacing the fuel hoses.

pauldvazquez

basic 944

pauldvazquez

T&T Racing

My suggestion is to first install the injectors to the fuel rail.
Check to ensure the o-rings on the intake manifold and are good, no chucks out, etc.

Then insert each injector into to the respective intake manifold hole. Make sure the injectors are square up with the intake manifold hole. Install the 4 bolts holding the fuel rail to the camshaft tower and tighten each bolt by hand until it touches the bracket. Then turn each bolt a little, do one, then the next one, etc by repeating the sequence until all bolts are torqued to the Porsche spec. You said that you lubricated each o-ring.

I discovered fuel leak at the intake manifold because I did not properly torque fuel rail bracket bolts and the bolts became loose and the o-rings deformed and chunk missing

Jfrahm

How would fuel well up from the manifold through the O ring? If the O ring was leaking you'd have to fill up the manifold with fuel wouldn't you? More likely it's leaking down from a bad injector as suggested.

wildcat077

That's one of the reasons people install Lindsey billet fuel rails ... we had one of our guys burn down the front
end of the car due to a leaking fuel rail at a race event.
I installed the whole kit on my race car, just for the peace of mind !

pauldvazquez

ClassJ

The Forgotten On

I personally just said screw it and installed a set of new Bosch design III 24lb injectors.

They're high impedance but work just fine in my dad's 87 NA. They don't have much of a pintle cap to worry about and slide in much easier than the stock ones with a light coat of DC111.

I just had to cut grooves in them with a hack saw so the clips have something to hold on to.

The idle was much smoother after this because they have 6 holes per injector instead of the 1 the factory ones have. They really atomize the fuel well.