'81 3.0 SC engine problems

[Das Schnell Ei]

Is the fuel thats in it old ? over a few months?

When you did have it running did it sound unhappy (popping and farting) and not want to hold an idle?

I would take the time and pull the fuel head off the top of the engine and clean the plunger

[boyt911sc]

Originally Posted by Mythos

Again thanks for the encouragement and the suggestions.

Tony I tried to shorten 'converted to a '79 SC(outside panels and almost everything mechanical) with a Carrera 2.7 motor' so it looked wrong. Not that it's important but the '81 3.0 SC motor was a relatively recent conversion(~2010).

Also I didn't just replace parts. Battery was completely dead and replaced after I first tried to jump start the cars with wires. (And I now have a frame of reference on how old it is)

I went with fuel acc. because the 'symptoms' fitted and it was a problem that even the previous owner had so I thought I might be lucky and it was that simple. Since I did that I also changed the fuel filter that was an old item I'd like to change anyway.

That said I didn't test first the old fuel acc. before replacing so...yep I might have been able to save some money.

What I don't understand is why after the change the car started with the first attempt while all the last week I tried a 20 different times with no success.

What I don't understand even more is why after that it was impossible to start again.

I'm after looking spark more thoroughly although as I said...it feels like a fuel problem to me(I have zero experience with 911 engines but not zero experience about cars).

I also checked for some loose or cracked hoses or something electrical moved(a ground loose). Nothing. Car looks exactly as I left it 7-8 months ago. (If there is a leak I think the car should first run to have any chance of identify it)

* the iceman I think the fuel pump runs like a '71 since it starts the moment you put the key on(which shouldn't happen to a 3.0 SC).

Mythos,

You want to know why you were able to start it once and never again after that?That was a fluke (a stroke of good luck). And you can not depend on luck all the time if want to be successful in your troubleshooting. These are the things you have to focus to get your engine to run again reliably.
a). Ignition (sparks, timing, valve timing).
b). Fuel pressures (residual, control, and system).
c). Fuel mixture (correct setting and absence of vacuum leak).

You will need a fuel pressure gauge to do a meaningful diagnostic test for any fuel injection system. This is a mandatory tool and if you don't have one, you would be making the troubleshooting work very difficult. Keep us posted.

Tony