2.7 Trouble
 

I have a 76 911S with a 2.7. I bought the car last March and drove it weekly until late Nov. From Nov to March, I only drove it on good days (every 3-4 weeks). Now with the weather getting better, I started driving it more and notice some weird problems.

The engine starts fine, idles fine, and when cold runs well. As the engine warms up, it seems to be missing while accelerating. Almost like it isn't getting fuel. I changed the fuel filter. Any ideas?

Pull all 6 injectors and put each into its own small jar. Put something under the flapper valve in the intake to simulate engine air flow and then turn on the fuel pump for a few seconds. Note the volume of fuel in each jar, should all be the same. It might be wise to buy new injector o-rings before this since they could probably stand replacing anyway, very easy to do. Hopefully you have the plastic fuel lines which are easy to flex as you remove injectors.

You might feel the exhaust pipes just after a cold start and find one that is cool that would indicate a non-firing cylinder.

Does it restart well when hot? Might be too high hot control pressure.

It restarts when hot without a problem. The "flapper valve,"? is that the pop-off valve? What do you mean put something under the valve?

Thanks for the help!

flapper valve
 

He is not talking about the pop off valve, he is talking about the plate in the back upper half of the airbox...push up on that and the fuel injectors will spray fuel.

( wow I had to edit this because I got off on the wrong problem.....)

other possibilities...
The fuel pump...going bad or clogged
The fuel accumulator....bad...
A bad Fuel injector...
or the worst...the CIS fuel distributor...

What about electrical....is it possible that a cylinder is switched? the distributor is out? cracked distributor cap or rotor...

Im just throwing ideas out, because you didnt mention any of this in the first post.

2.7 Rough after warmup
 

My 2 cents....check your points as well.:D

I now think it is an electrical ignition problem. As such, I am exploring those issues (blindly). I have an MSD 6A with Blaster Coil. I had new points added yesterday, still the same problem. MSD suggested bypassing the ignition box going directly to the points to see if it is an ignition problem. I am not sure how that works. Another person suggested pulling the distributor and checking it out. The cap is not a Bosch cap (not sure what brand) but it is intact. Any thoughts or recommendation on the best way to proceed?

I have replace the fuel filter, run a new tank of fresh gas, checked the accumulator. I did not check the injection system yet because i think this is electrical. It only happens when the engine is warm. Engine idles fine. I also had a bouncing tach that predated these other issues. Since the tack runs through the ignition box, I am thinking they are all related.

you see
 

You see its the whole warm motor thing that says "hey Im a fuel system problem" but then the missing at high RPM thing says ignition.

How about eliminating the points by going solid state....I did with my blaster and MSD and I have yet to complain about it.

Hmmmm

I think it is fixed! I swapped out the MSD 6A with one from a local guy. Car ran smooth again! I will send my 6A unit back to see what was wrong with it.
Thanks, Tim