Golf Mk2 GTI 8V PB won't start

October 25, 2021, 12:44:32 PM

Hello everybody,

I am recently having some issues with my Golf.

At first, it started with the car losing power and then gaining it again. Sometimes, it would stop and if I waited few mins, it would restart. Then it suddenly stopped. I thought the fuel pump had packed ups so I changed it for a brand new Bosch. But nothing,
I found out it was my ignition switch which I changed for a brand new VW one. The car started first time and drove well.

After a couple of weeks, the car packed up again. I looked at the switch and everything normal (fuel supply ok as injectors were spraying and I had voltage going to the coil). I found that the HT pin of the coil was corroded. So I changed the coil, the spark plugs (as the car was due a service), put a fresh set of HT leads (the other ones were in poor condition), new dizzi cap & rotor even the new TZH module. The car wouldn't start. No spark to the plugs so I changed my distributor (new bosch one) and changed the blue temp sensor (bosch) and connector (vw) (as I found the cables were cracked at the base of the connector). Once fitted, I timed the car and had a mechanic to check and the car started.

After few months of running, whilst going to work, the car lost power and wouldn't restart (it was getting warm). I got towed back home (luckily only few mins away) and checked the sparks and none but I had voltage to the coil. So I thought it would be the distributor (hall sensor).

I bought a new distributor (bosch again) and fitted it a couple of days ago, The car started but the revs were doing up and down for a little while and then stabilized. I went to pick up my strobo light to do the timing and when I started to fit it, the engine cut off and wouldn't restart (it was just starting to get warm). I checked all the cables and found a brown and white earth (normally attached on the engine block) broken and the torsaded earth strap from battery to block almost broken as well. I repaired both with new connectors, cleaning the areas to provide better contact. I tried to restart the car but nothing.

I then went through the all ignition system:
- fuel pump primes and injectors spray
- ignition switch ok as there is voltage to TZH module
- low voltage of from TZH module to coil ok: 1.8v for 2 seconds then nothing
- low voltage feed to distributor hall sender (3 pin connector) ok: 12V
- check cap & rotor ok
- checked manually hall sender by unbolting dizzi, putting main HT lead to the engine block whilst ignition on and turned the dizzi shaft. At each aperture of the dizzi cup, there was a spark between the HT lead and the engine block. I did the same on the previous dizzi and both worked.
- reset timing with following procedure:
   - turn over engine to find TDC (little notch next to big on on flywheel)
   - align little notch to arrow of the aperture of the gearbox
   - put the oil pump pin parallel to the engine block
   - fit dizzi (ensuring hall sender is on the right)
   - align rotor with notch in dizzi body
   - fit dizzi cap
   - set HT leads in correct order: 1,3,4,2 clockwise with HT lead #1 from cylinder #1 (the cylinder the further on my left side, near
air filter) being above the plated side of the rotor
   - check the spark plugs (mix seems to be rich), clean them, tested them with both in line spark tester and directly to the block.

All the plugs have spark, the fuel is coming into the cylinders but the car won't start.
I am baffled.

Can anybody help ?

Thanks,
Florent

Re: Golf Mk2 GTI 8V PB won't start

Reply #1 – October 25, 2021, 05:08:22 PM

Sounds like it could be related to the ISV (https://www.vwgolfmk2.co.uk/clubforum/index.php?topic=68.0). Also check you have a good solid earth on the gearbox, If not it can fry the ECU.

Then read this:
https://www.vwgolfmk2.co.uk/clubforum/index.php?topic=141.0

Re: Golf Mk2 GTI 8V PB won't start

Reply #2 – October 26, 2021, 12:59:55 PM

Hi,

Thank you!! I have checked the earth strap to gearbox casing and it was broken so I repaired it.

I will have a look at the links you have sent.

Also, could it be the fact that my timing is potentially out by 180deg ?

Thanks,
Flo

Re: Golf Mk2 GTI 8V PB won't start

Reply #3 – November 03, 2021, 05:09:29 PM

Hi all,

I have now found the problem!

The timing was definitely 180 degrees out. I managed to start the car and when the engine started to be hot, it cut out again. No spark to distributor. After re-investigating the earth wirings, the voltage at the ECU, Hall sender, etc..., I was left perplex.

Then I checked the resistance of the coil by measuring it between the low voltage inputs (- and + coil pickups) and HT output (where you plug your HT lead). You should be reading the same number if you switch the low voltage input from one to another (3ohms ish if I remember). Result was a difference of 5ohms. I then swapped the coil and restarted the car first time and no issues since.

so lesson learnt: don't always assume something is working correctly, always test your elements to ensure each one of them are working properly as you could have an intermittent fault.

Thanks,
Flo

Re: Golf Mk2 GTI 8V PB won't start

Reply #4 – November 03, 2021, 06:07:33 PM

What was 180 degrees out? The dizzy?