Nasty fuel leak

dfink · 01-19-2007, 03:32 PM

after putting engine back in car and getting ready for break in the first thing there was a fuel leak. Looked like injector o-rings so I replaced the o-rings today. Still blows fuel like crazy. It looks like it is coming from around the intake gaskets. I used new paper type gaskets on each side of the insulator and torqued to spec. #3 on left and #5 and #6. I suppose it could be air from the fan shroud that makes it look like it is coming from the intake.
Can fuel blow out like that around the intake runners or do I still have injector leaks. It never leaked a bit before tear down and I never took the intake manifold apart as it was fine before.
What a PITA don't want to run very long to break in cause of fire potential. When I say leak I mean leak not just a little dribble.

pozee · 01-19-2007, 03:50 PM

Are you sure it's not the fuel line or fitting/s?

dfink · 01-19-2007, 04:04 PM

Checked the fuel line and fittings all those areas are OK. Top of fan shroud is dry so it's not running down from there. I will have to try and determine if its the injectors or the manifold. I guess I don't understand why fuel would be coming out the manifold as when the injector fires the cylinder should be on intake and sucking unless the injectors are stuck and pushing fuel continuously. The engine runs pretty good and idles. It almost seems to leak worst at idle.

Nitrometano · Nitrometano's Garage

do you replace the fuel injectors o-rings???

dfink · 01-19-2007, 04:32 PM

Yes replaced all the injector o-rings. As I think about it and do a little more searching I am starting to think that I must have injectors that are stuck open. I am thinking that setting dry for a couple months was not good for the injectors. Would this cause the spitting issue I am seeing. It seems like way too much fuel to just be a leaking injector o-ring.
I think I should re-pull all the injectors and send off to be checked before I ruin the cylinders by washing them down. I find it hard to believe that I would get that much fuel coming out the intake manifold.
Any thoughts on this. It would probably be good to get the injectors cleaned anyhow.

Nitrometano · Nitrometano's Garage

too much fuel from the intake manifold??? that would be dangerous for the engine. If to much fuel enters to the combustion chamber, when you start the engine, the piston would try to compress that liquid fuel and you can broken the pistons or rings. I have seen 2 cases of that.

I think that you would need to check the injectors. Maybe you're right. They are stucked and gets opened all the time.

dfink · 01-19-2007, 04:43 PM

Great I just had to post something cause my last post about the the fuel leak was "666" just couldn't leave it there.

dfink · 01-20-2007, 06:07 AM

OK I re-pulled the left bank of injectors and thought I would check to see I could blow air through therefor verifying stuck open. What I found was that when I put air to the inlet of the injector fuel leaked out around where the silver shaft exits the body of the injector. Two of the injectors were dry while trying to blow out. I don't which but only one on that side was leaking so I suspect it was the one that now leaks around the shaft.
Question is... Is that injector shot, can they be rebuilt or should I just replace. I suspect that I will find the same condition on the other side.

dfink · 01-20-2007, 08:10 AM

Well I guess this is now just a log of my adventures. So I will log away. Called witchHunter and discussed the problem and the bosch injectors are not servicable if leaking between the body and the shaft so it looks like new injectors for me. I still find it strange that there were no leaks before the engine tear down.
So for anyones future reference if you blow air through the injector and it leaks out around where the shaft exits the body you are shafted.... If you can spin or rotate the shaft area they are likely toast even if they don't leak now. This has now turned into the most expensive item on the rebuild by far. But while it was running Oh man did it sound wicked.

MAS956 · 01-20-2007, 08:32 AM

It might be worth peace of mind to pull all six and send them out for cleaning/flow testing. That way you'll know for sure after all the work you've done to get it back to this point.

dfink · 01-20-2007, 11:16 AM

Nothing that $650.00 can't fix. I have 6 new ones coming from the local porsche dealer. Sorry I didn't get them here but mucho price difference.
Decided to do all six because if three of six are bad the others can't be too far behind. These should last the life of the car.