I have a 1991 Volkswagen Fox with a 150000 miles on it. It runs fine when it is running, occasionally it will just shut off while driving along and it won’t restart not until I get it towed. Once the tow truck drops it off at home then it starts up. I have troubleshoot it enough to eliminate the fuel system and narrow it down to the ignition system. When it is not starting there is no spark present. I changed out the ignition module but no luck. Could it be the hall sender in the distributor? I hate to buy a new distributor and still not solve my problem of it cutting off. Could it be the ignition coil?
Coils can fail intermittently, but it is not common.
Hall effect sensors fail more often. One of the failure points is the wire between the sensor and the distributor case, or right where that wire passes through the distributor case. It can fatigue due to flexing and break inside, while still looking OK on the outside. Also look for corrosion in the plug.
We installed a $40 junk yard distributor once, but when the junk yard unit failed a few years later, we bit the bullet and bought a new one (we drive our cars for a very long time).
I had an 1988 fox wagon.I always keep an extra ignition module,distributor module and fuel pump relay in the glove box.The hall sensor can be replaced with out replacing the entire distributor.Just like the bad connection on the wire to the distributors hall sensor,the same can happen from the cis or bosch ignition module.To test the connection turn the ignition on and disconnect the wires at the distributor.Then have some one crank the motor with the key ignition or hand held starter button.While the engine rotates connect and disconnect the distributor wires at the distributor.If you have a spark the Hall senor is bad,if you don’t,check your cis ignition module and connections.Plus check your negative ground connection behind the dashboard.Some times the bundle of wires become lose and need to be crimped down on really hard.The wires are lite brown/tan and lead into a giant butt end connector that some times needs a little attention.You can pull parts off of VW Golfs and Jettas from the junk yard and some older Audis.I would but a new coil on just to do it that way it won’t come back and haunt you later.Coils heat up and fail ,then after they cool down they will work again.Good luck it is just the beginning of being nickeled and dimed to death.