1976 911s turns over but wont start

[996AE]

1976 911s 2.7 stock engine turns over but wont start. CIS just gone through and was running. new cap, rotor and plug wires with professional tune up. Valvez done. CDI humming. New fuel pump and filter with CIS adjustments.

just prior to no start car was hesitating if cruising. Peddle down ran strong. idle good.

Ideas before towing to garage?

[Joe Bob]

Check spark at the plug.....if you have spark, spray some ether/quick start into the intake.

No spark, it's the CDI box, spark and it starts with ether, it's a fuel delivery issue. Likely a failed fuel pump or the electrical supply to it/relay.

[996AE]

didnt touch a thing. went to garage, turned key. started right up.

yesterday couldnt get it to fire.

? ideas

[dipso]

Are the points opening?

[996AE]

could old points cause this intermittent problem. Happened twice before thus the major tune and CIS go throug and new fuel filter and fuel pump.

[dipso]

Originally Posted by mortimerrick

could old points cause this intermittent problem. Happened twice before thus the major tune and CIS go throug and new fuel filter and fuel pump.

I don't know about old, but if they are not adjusted properly, that could be the problem.
Just check em, takes 5 minutes.

[mysocal911]

Originally Posted by dipso

I don't know about old, but if they are not adjusted properly, that could be the problem.
Just check em, takes 5 minutes.

Right, use of a test light connected to 12 volts and the other end connected to the points
connection on the distributor can help verify whether the points are a problem.
The test light will flash as the engine turns over indicating an opening and closing
of the points.

[996AE]

Thanks. I'm on it first thing in the AM. Will report back. Intermittent problems are the worst.

[dipso]

If you don't have a test light just take off the cap and rotor, turn the motor by hand and visually look at the points as the shaft turns.
If the felt pad has worn down, the points will no longer open and result in the problem you are having.
It happened to me once.
Use a feeler gauge and check the points gap.

[mysocal911]

Originally Posted by dipso

If you don't have a test light just take off the cap and rotor, turn the motor by hand and visually look at the points as the shaft turns.
If the felt pad has worn down, the points will no longer open and result in the problem you are having.
It happened to me once.
Use a feeler gauge and check the points gap.

For proper determination of an electrical closing & opening, one needs to use a test
light or a volt meter. A visual inspection of the points does not verify whether the points
are making an electrical connection when closed.

[996AE]

Points appear to be operating properly. Mechanic that did major tune service said he didnt replace points as they looked good. but, they are old.

other ideas on why sometimes starts on first turn of key and other times it wont start, but turns over?

[manbridge 74]

I'd be looking closely at the 38 year old shielded green wire at distributor.

[996AE]

checked all wires. One frayed a bit. Cleaned it up but no change. sometimes starts first turn of key, sometimes I cant get it to fire.

After more time today car started after pumping gas peddle. Then, when i shut it off it dieseled and after after seconds a loud, very loud backfire well after car was off.

[timmy2]

Originally Posted by manbridge 74

I'd be looking closely at the 38 year old shielded green wire at distributor.

Normally no green wire to distributor pre-78 with points unless there has been an engine or distributor swap.

[996AE]

No green wire on my 1976 911s 2.7.

checked all wires and connections.

cant get it to start this afternoon.

flat bed to shop Monday.

[afterburn 549]

Originally Posted by mortimerrick

No green wire on my 1976 911s 2.7.

checked all wires and connections.

cant get it to start this afternoon.

flat bed to shop Monday.

Wow...shop?
More money then time?

[timmy2]

From your first post about a tune up and CIS adjustments, it sounds like they didn't get it right.
Any troubleshooting and adjustments should be free!
(Yeah, Right, like any shops stand behind their work these days except for a very few)

[996AE]

Wont start. I have hit my skill limits. Not happy with the 150.00 an hour shop rates but I cant find the problem. Since it is intermittent that seems to always add to the story.

[996AE]

ps. afterburn. plenty of time. i am retired. but, i have run out of ideas and the forum has too!

IF YOU HAVE SOME CONSTRUCTIVE INPUT, PLEASE SHARE.

[afterburn 549]

Not trying to flame you.BUT, we could have fixed it......