Intermittent ground primary circuit?
Symptoms: driving 30 mph , stalls.
Sometimes , it will only miss and continue.
Sometimes it stalls and usually immediately restarts.
Every once in a while it needs to sit and then restart.
Replaced Autozone PN F-133 Ignition Control Module several times to no avail. I hear that these are notorious for failures. Not sure.
Suspect that I am dropping the primary circuit ground.
How many and where should I redo the grounds?
I suspect the distributor has a ground somewhere internally
( where , what to look for? ) that needs a redo.
I suspect that the engine block has a ground that needs a redo.
Would appreciate any confirmation / guidance.
Am prepared to redo the grounds with dielectric grease.
Perhaps I am looking in the wrong place.
I see the internet is full of 258 / carb /MCU stall postings.
Do not feel that it is carb issue at all.
Tach drops to zero immediately and gives no signs of stumbling .
Abrupt cut-out of ignition.
This issue has persisted for years.
Four mechanic shops have been unable to solve.
In pursuing the cause, replaced:
distrib cap, rotor, plug wires , pickup coil, MCU, ICM, ignition coil,carburetor remanufautured.
Is there a recurring short /drop ground inherent in this 258/ carb?
It is my understanding that the MCU bypass would not solve this .
As I understand the Nutter Bypass, it removes the fine tuning controls of fuel/air mixture and of timing; it does not address a massive failure.
Am I incorrect or correct about that ?