VW mk2 Golf 1300 transistorized ignition - Golf engine suddenly cuts out - golf-driver

I have a mk2 Golf 1300 with transistorized ignition

The engine cut out whilst driving, it would not re-start after many attempts, the engine did crank though.

The AA man said the rotor arm was burnt out and that the distributor hall sensor was suspect as it was giving no output.

The following day I replaced the rotor arm and the engine started, but after a minute it cut out again and would not re-start.

When I removed the old rotor arm I noticed the distributor shaft was wet with oil, there was no oil inside the distributor cap and no oil on the outside of the distributor. The HT leads appear in good condition.

Is it possible that there is oil leaking into the distributor thus causing the hall sensor to short circuit?

I've assumed that the distributor hall sensor is not broken as the engine re-started the next day when I replaced the rotor arm, have I assumed wrong?

Here is the AA man's report ("Static battery 12.3 V, engine cranks ok, no spark from HT lead & coil checked feed in/out coil. checked camshaft turning - no switching from coil or hall sensor. cheched feed & earth - ok")

VW mk2 Golf 1300 transistorized ignition - Golf engine suddenly cuts out - elekie&a/c doctor

Oil in the dizzy will have no effect on the hall sensor.However it is possible for the pick up to be intermittant in operation and cause the problem you are experiencing.May be a good idea to check the connector on the ignition amplifier which is located up under plastic panel by wipers.hth

VW mk2 Golf 1300 transistorized ignition - Golf engine suddenly cuts out - golf-driver

The connector on the ignition amplifier / switch unit was ok.

Using the Haynes manual I checked the switch unit, hall sensor & coil. The differences recorded were;

For the switch unit check; with ignition on and hall sensor plug removed the voltage across the outer terminals of the hall sensor plug was 10 volts (Haynes said this should be 5 Volts).

For the hall sensor check; (with ignition on and the ht lead removed from the distributor & earthed) the voltage across terminals 3 & 6 of the switch unit (rubber boot pulled back) was a constant 10 volts even though I hand turned the enigine. (Haynes said this should of alternated between 0 & 2 volts).

The resistance of the coil secondary winding was 3K ohms (resistance for the after 1987 golf should be 8K ohms, resistance for the pre 1987 golf should be 3K ohms ). I have the after 1987 golf.

So whats at fault here, the hall sensor or the switch unit?

VW mk2 Golf 1300 transistorized ignition - Golf engine suddenly cuts out - elekie&a/c doctor

Simple test for hall trigger is,remove 3 pin plug to dizzy,volts across the 2 outer terminals with ign on should be around 10 volts.Take a piece of wire and flash the centre pin to earth with the coil centre lead removed from dizzy and near metal.There should be a momentary spark.If so then the coil and amp are ok.hth

VW mk2 Golf 1300 transistorized ignition - Golf engine suddenly cuts out - Railroad.

The Hall sensor plug has three terminals marked +, 0 and -. The + terminal at the plug should show anywhere between 5v and 12v. The - terminal goes to earth, and the 0 terminal is the switching signal to the ECU. A digital multimeter cannot display a rapid voltage change from 12v to 0v when displaying DC Volts, so instead it will show somewhere in between when the engine is cranking if the sensor is working. The switching signal goes to the ECU which in turn sends another switch to the ignition module. This can be measured at the centre terminal at the ignition coil/module. By the way, coil/module failures are far more common than hall sensors.

You need to see if the coil is switching. If it is but you have no spark then the module is faulty. If it's not switching then you need to go back to the hall sensor. Also ignition switches are not uncommon failures on these, so make sure you have a 12volt supply to the coil at all times when the ignition is on. You will find a small flap on the coil. Underneath it is two tags. These are the coil positive and negative terminals. Check here for the coil voltage supply and for switching on the negative side.

VW mk2 Golf 1300 transistorized ignition - Golf engine suddenly cuts out - golf-driver

Regarding the hall sensor check; The enigne was turned slowly by hand and the voltage on my analogue meter stayed a constant 10volts.

I reckon the hall sensor is faulty, I will replace this first.

As I have not taken apart a distributor before will it be easier for me to just replace the whole distributor with a second hand distributor (thats done 100k) rather than insertin a new hall sensor? I will still have check the ignition timing won't I?

VW mk2 Golf 1300 transistorized ignition - Golf engine suddenly cuts out - golf-driver

I replaced the distributor with a second hand distributor (used the same cap & ht leads though). The engine started and I left it running for 15mins, after an hour I returned to start the engine but it failed to start, just the usual starter motor cranking the engine.

Surely then the hall sensor on the first distributor was not at fault? so what next?

 

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