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My first post. At my wits end. I’ve scoured all of the internet for answers. Seems other people had similar issues but their remedy’s aren’t curing mine.
My US 1978 911sc will be driving along fine and then will die. The electronics are fine. Lights are fine. Radio is fine, just the engine will stop producing spark. I’ll coast to the shoulder or an exit ramp and sit. The engine will sometimes restart immediately and sometimes it will crank and crank and not start. I notice that unless I either wait a certain amount of time or I unplug the 6 pin then plug it back in It will start. This last time it didn’t seem work but I carry a spare permatune gen 3. I’d unplug the one in the car and just plop the replacement in and the car will slowly sputter and idle normally. This will allow me to nurse the car back but will sometimes stall on me again and leave me on the shoulder. Then I plug in the original and I’ll continue driving. The car will still stall out. I have a new battery, cleaned all the grounds and had my distributor rebuilt recently by partsklassic and I’ve replaced the power harness and I have a lot Brand new green wire.
One year prior to this issue I’ve replaced the alternator and the external Voltage regulator.
I’ve checked Fp relay, pressures. Etc. I don’t believe it a fuel issue. All fuses and connections checked.
I have two gen 3 permatunes , a black bosch coil and a brand new Msd blaster high vib coil. All combinations of these components will exhibit the same symptoms. I find it unlikely that every single one of these components are failing in the exact same ways.
one thing I have not tried is unplugging the Rev limiter that’s behind the fuel gauge. Would this be the source of any issue?
My first post. At my wits end. I’ve scoured all of the internet for answers. Seems other people had similar issues but their remedy’s aren’t curing mine.
My US 1978 911sc will be driving along fine and then will die. The electronics are fine. Lights are fine. Radio is fine, just the engine will stop producing spark. I’ll coast to the shoulder or an exit ramp and sit. The engine will sometimes restart immediately and sometimes it will crank and crank and not start. I notice that unless I either wait a certain amount of time or I unplug the 6 pin then plug it back in It will start. This last time it didn’t seem work but I carry a spare permatune gen 3. I’d unplug the one in the car and just plop the replacement in and the car will slowly sputter and idle normally. This will allow me to nurse the car back but will sometimes stall on me again and leave me on the shoulder. Then I plug in the original and I’ll continue driving. The car will still stall out. I have a new battery, cleaned all the grounds and had my distributor rebuilt recently by partsklassic and I’ve replaced the power harness and I have a lot Brand new green wire.
Why?
Originally Posted by NeunelferPNW
One year prior to this issue I’ve replaced the alternator and the external Voltage regulator.
I’ve checked Fp relay, pressures. Etc. I don’t believe it a fuel issue. All fuses and connections checked.
I have two gen 3 permatunes , a black bosch coil and a brand new Msd blaster high vib coil. All combinations of these components will exhibit the same symptoms. I find it unlikely that every single one of these components are failing in the exact same ways.
one thing I have not tried is unplugging the Rev limiter that’s behind the fuel gauge. Would this be the source of any issue?
any help is appreciated. Thank you.
Check 12V & ground to the CDI, and at the large black multi-pin connector on the left side in the engine compartment.
__________________
Loren
Systems Consulting - Automotive Electronics
Specializing in Porsche cars http://www.systemsc.com/
My first post. At my wits end. I’ve scoured all of the internet for answers. Seems other people had similar issues but their remedy’s aren’t curing mine.
My US 1978 911sc will be driving along fine and then will die. The electronics are fine. Lights are fine. Radio is fine, just the engine will stop producing spark. I’ll coast to the shoulder or an exit ramp and sit. The engine will sometimes restart immediately and sometimes it will crank and crank and not start. I notice that unless I either wait a certain amount of time or I unplug the 6 pin then plug it back in It will start. This last time it didn’t seem work but I carry a spare permatune gen 3. I’d unplug the one in the car and just plop the replacement in and the car will slowly sputter and idle normally. This will allow me to nurse the car back but will sometimes stall on me again and leave me on the shoulder. Then I plug in the original and I’ll continue driving. The car will still stall out. I have a new battery, cleaned all the grounds and had my distributor rebuilt recently by partsklassic and I’ve replaced the power harness and I have a lot Brand new green wire.
One year prior to this issue I’ve replaced the alternator and the external Voltage regulator.
I’ve checked Fp relay, pressures. Etc. I don’t believe it a fuel issue. All fuses and connections checked.
I have two gen 3 permatunes , a black bosch coil and a brand new Msd blaster high vib coil. All combinations of these components will exhibit the same symptoms. I find it unlikely that every single one of these components are failing in the exact same ways.
one thing I have not tried is unplugging the Rev limiter that’s behind the fuel gauge. Would this be the source of any issue?
any help is appreciated. Thank you.
You own and are using a Permatune, and have two??????? What was installed before? The original factory '76 911 used the blue Permature, but this was a three pin unit.
You own and are using a Permatune, and have two??????? What was installed before? The original factory '76 911 used the blue Permature, but this was a three pin unit.
I’m not the original owner of this 911sc. It was equipped with a Generation 3 Permatune. A lot of people suggested that culprit be the Permatune so I bought an identical model. Both behave the same and I’m dismissive of that being at fault. I have two different coils and they all act similar.
the distributor, although rebuilt will vary from 675 ohms to 575 ohms and cranks .6 AC.
I’m not the original owner of this 911sc. It was equipped with a Generation 3 Permatune. A lot of people suggested that culprit be the Permatune so I bought an identical model. Both behave the same and I’m dismissive of that being at fault. I have two different coils and they all act similar.
the distributor, although rebuilt will vary from 675 ohms to 575 ohms and cranks .6 AC.
Originally Posted by GothingNC
Ditch the Permatune.
See I'd you can borrow a Bosche CDI box for a while to test.
im in the process of ruling it out first. I have two generation 3 permatunes that work but behave the same and one brand new generation 6 and failed to work out of the box.
My first post. At my wits end. I’ve scoured all of the internet for answers. Seems other people had similar issues but their remedy’s aren’t curing mine.
one thing I have not tried is unplugging the Rev limiter that’s behind the fuel gauge. Would this be the source of any issue?
any help is appreciated. Thank you.
Possibly, however the way the rev limiter works is by interrupting the fuel pump. I think you would still have spark. But it is very easy to unplug, I would try it. You have nothing to lose.
im in the process of ruling it out first. I have two generation 3 permatunes that work but behave the same and one brand new generation 6 and failed to work out of the box.
i had one too recently on my buddies SC .. threw in my CDI box and fixed,, not sure what generation he had but everything was potted in so rendered it garbage.
02-27-2023, 02:31 PM
911sc dies while driving.
