My 1969 911T just turns off while driving

[hemmah]

I have a 1969 911T without CDI. My system turning off problem happens every day or so - intermittent problem. What happens is I'm driving along and the entire system will turn off like I have turned off the ignition with the key. I get in the breakdown lane and turn the key off and then on again. The system turns on and the engine will start again.

My first though is the ignition switch is starting to get bad - wanting to open when it is the on position. Very bad since they don't make these ignition switches anymore.

My second thought is that there is an electronic switch somewhere that is opening when it should be on. I don't know of an electronic switch in this old 1969.

Thoughts and suggestions?


Steve

[jstobo]

It could be the ignition switch.
It could be a loose or bad power wire(red) from fuse box to switch.
It could be loose or bad fuse at fuse box for power wire.
Could be bad ground at batteries.
Could be bad or loose positive lead from batteries to fuse box.
Could be bad fuse box.(They have a conductor on the back so that the battery positive can feed several fuses.)
Or it could be another wiring problem.

Anyway-have fun troubleshooting.

[HawgRyder]

On my 69S there was a switch on the MFI for deceleration...it went to the little electronic box that killed the ignition while you were at speed but lifted you foot....so that the engine didn't backfire.
Is there a similar thing on the carb version?
If so...perhaps it's at fault and thinks you have lifted the throttle foot and is killing the ignition.
Bob

[Roger 911]

Originally Posted by HawgRyder

On my 69S there was a switch on the MFI for deceleration...it went to the little electronic box that killed the ignition while you were at speed but lifted you foot....so that the engine didn't backfire.
Is there a similar thing on the carb version?
If so...perhaps it's at fault and thinks you have lifted the throttle foot and is killing the ignition.
Bob

I believe a '69T still used carbs (if its stock). I think MFI wasn't added to the T until '72.

Roger

Ignore this. I see you mentioned "carb version".

Sorry.

[Classic]

Is it when you go over a bump? Or running on smooth asphelt?

I had a similar problem with my 69er when I first got it, when I went over bumps.

Turned out to be an ill fitted battery terminal on an ill fitted battery that would touch the body some times when I'd go over a bump.

From there start running back, fuse switch. Time for some continuity testing, but I feel it may be an Intermitent short, which are always fun to find.

[hemmah]

All

Thanks for the inputs. Time to go hunting the electrical problem. I'll feedback what I find.


Steve

[hemmah]

Oh Classic,

Problem happened once on flat road and once climbing a hill at the top of the road.


Steve

[hemmah]

Roger,

You are correct my 69 T has Weber carbs.


Steve

[hemmah]

The problem looks like a poor 12V contact point in the engine compartment. I did a quick clean and all seems well. It has been a week without a problem. I will be adding MSD soon and will clean it further then.

Thanks All for your help


Steve