My fuel-leak, and how i cured it. i.e. fuelrail
10-19-2017, 09:39 PM
#1
My fuel-leak, and how i cured it. i.e. fuelrail
My fuel-leak, and how i cured it. i.e. the fuelrail
This is an answer on my own question that i posted her: https://rennlist.com/forums/944-and-944s2-forum/1027552-my-fuel-leak-again.html
The other week i started the car. It was reluctant and was only running on three cylinders and spewing out white smoke from the exhaust.
I lifted the hood and there was petrol seeping from the rail and down the third injector from front. Obviously turned of the car and started to search for answers on the net. Orded new o-rings x4 from the local porscheshop the day after. 44 euros and the little plastic rings where the wrong size!
Ended up reusing the old plastic, but will rebuild all this crappy engineering in some near future, meaning the rail and everything connected to it.
Followed some link, (to Clarke's i think), that said that you should remove the four boults and the vac/fuel-lines and just pry the fuelrail whit your hands straight up, and the injectors would come of whit the rail.
Don't do that!
One come off whit the rail the others was stuck on the intake. You need to undo the little metal clips on all injectors, and then take them off from wherever there are stuck to.
I then cut of the o-ring from the injectors and used a 9mm open wrench and a wirecutter as a lever and pried off the little "hats". The where very hard after thirty years, and so where the lower o-rings who where flat on the edge and hard to the touch. I used a 10mm socket for installing the new hats. And i used a "bits holder" whit an old o-ring as catcher, to clean out the grime in the manifold holes, stick it in blow out grime whit pressured air.
Don't forget to change the o-ring on the fuel pressure regulator.
Refitted the injectors whit new oringsī, new "hats and "old" plastic rings! Cleaned out and the electrics and, Dont forget the clips!
Started the engine. Still leaking!
More searching on the Internet and i decided to just braze the rail. Done some brazing in my youth and bought some crack search on spraycans and some silver-rods and two small cans of propane.
Dismantle ewerything from the rail before you start!
Started to clean whit first can #1, by smell i would say itīs just brakecleaner. Soaked the rail in "ink" from can #2 and then cleaned it whit water and sprayed on developer. Sure enough, there was leaks around injectormount #3 three, a pore on #2 and a crack inside the rear mounting.
Brazed the living h*ll out of everything!
New cracksearch revealed that more brazing where needed on the mount. This proved to be difficult. The "corner" where the crack is, is hard to reach whit the flame and sort of "bounce" off it. Ended up just "bridging" up the corner whit solder and maked sure the edges was melted in whit the surrounding metal.
Propane is to weak/cold for this job. But i need the car to run and this is considered to be just a temporary fix.
The car runs now. It runs like 10.000 km each year so there is always something that needs fixing.
I will rebuild the fuelrail. Probably whit a milled chunk of aluminum.
For those who thought of fuel-lines. Yes, the small line on the rail was a warrantyjobb done some twenty years ago and i fixed the low pressured side when i bought the car three years ago.
However, i gonna rebuild all of the fuel-lines, rail, and possibly the injectors (there is some thirty year old plastic inside them to).
I do not like fires!
Didnīt get how to fix in pictures whitin the text. But here is some.
This is an answer on my own question that i posted her: https://rennlist.com/forums/944-and-944s2-forum/1027552-my-fuel-leak-again.html
The other week i started the car. It was reluctant and was only running on three cylinders and spewing out white smoke from the exhaust.
I lifted the hood and there was petrol seeping from the rail and down the third injector from front. Obviously turned of the car and started to search for answers on the net. Orded new o-rings x4 from the local porscheshop the day after. 44 euros and the little plastic rings where the wrong size!
Ended up reusing the old plastic, but will rebuild all this crappy engineering in some near future, meaning the rail and everything connected to it.Followed some link, (to Clarke's i think), that said that you should remove the four boults and the vac/fuel-lines and just pry the fuelrail whit your hands straight up, and the injectors would come of whit the rail.
Don't do that!
One come off whit the rail the others was stuck on the intake. You need to undo the little metal clips on all injectors, and then take them off from wherever there are stuck to.
I then cut of the o-ring from the injectors and used a 9mm open wrench and a wirecutter as a lever and pried off the little "hats". The where very hard after thirty years, and so where the lower o-rings who where flat on the edge and hard to the touch.
I used a 10mm socket for installing the new hats. And i used a "bits holder" whit an old o-ring as catcher, to clean out the grime in the manifold holes, stick it in blow out grime whit pressured air.Don't forget to change the o-ring on the fuel pressure regulator.
Refitted the injectors whit new oringsī, new "hats and "old" plastic rings! Cleaned out and the electrics and, Dont forget the clips!
Started the engine. Still leaking!
More searching on the Internet and i decided to just braze the rail. Done some brazing in my youth and bought some crack search on spraycans and some silver-rods and two small cans of propane.
Dismantle ewerything from the rail before you start!
Started to clean whit first can #1, by smell i would say itīs just brakecleaner. Soaked the rail in "ink" from can #2 and then cleaned it whit water and sprayed on developer. Sure enough, there was leaks around injectormount #3 three, a pore on #2 and a crack inside the rear mounting.
Brazed the living h*ll out of everything!
New cracksearch revealed that more brazing where needed on the mount. This proved to be difficult. The "corner" where the crack is, is hard to reach whit the flame and sort of "bounce" off it. Ended up just "bridging" up the corner whit solder and maked sure the edges was melted in whit the surrounding metal.
Propane is to weak/cold for this job. But i need the car to run and this is considered to be just a temporary fix.
The car runs now. It runs like 10.000 km each year so there is always something that needs fixing.
I will rebuild the fuelrail. Probably whit a milled chunk of aluminum.
For those who thought of fuel-lines. Yes, the small line on the rail was a warrantyjobb done some twenty years ago and i fixed the low pressured side when i bought the car three years ago.
However, i gonna rebuild all of the fuel-lines, rail, and possibly the injectors (there is some thirty year old plastic inside them to).
I do not like fires!
Didnīt get how to fix in pictures whitin the text. But here is some.
