Solving that electrical gremlin...

[Golfer]

Ok folks, here's the downlow...

Months ago, Shaneth and I were driving across the Storey Bridge, in Brisbane (4 lanes each way, big long thing) to pick up a set of Weitec springs, when the Mk2 decided to die. Big time...

Got started, after being honked at 400 times, then 2km down the road it stopped again, and stayed stopped...

Darned thing wouldn't start no matter what we tried. "Dan" off the forum came out to help, and still nothing. So there we are, 9pm at night, waiting for the RACQ...

By some miracle, it started 30 seconds before the RACQ got there, so no fault could be found. And mysteriously, the gremlin disappeared...

Cut to 6 and a half months later...

Driving along, minding my own business, engine stops, then starts itself back up. I think to myself "That's kinda like what was happening before" but think nothing of it. That night, driving along to a mates place, the Mk2 finds the magic death gremlin again...

Stuck on the road, middle of nowhere in Kingscliff, waiting for the NRMA...

I try to start dozens of times, to no avail. The NRMA arrive an hour later, and the car starts the second time we try... DAMN

SO I get home, and go to drive into town the next day, the car stops. And stays stopped...

...for a week...

Now folks, if you don't want this to happen to you, here's what to do...

Thanks to Peter Jones for helping me out with the necessary details in a tight spot. I explained my problems to him and he was amazing. Sent me the PM's in the next 2 posts...

[Golfer]

This was the first PM between Peter and I...

I ordered in a new ignition module and hall effect module for the ignition. I had them sitting on the shelf for about a week when the old ignition module in the car blew up one morning. I was pretty pleased with myself for anticipating that one!

I'll change out the distributor module once I've got the motor started back up. I don't want to change everything all at once, it gets too hard to fault find.

Hey Pete,

Mate I've been having major dramas with my car, it is not getting any spark whatsoever. At first the problem would come and go, sometimes the car would restart right away, other times it would leave me stranded on the side of the road for an hour, then the car would start. It is definitely a problem with the ignition system, but I have no idea what it could be... The coil is good, but beyond there I didn't know what I need to look for.

Were your problems in any way similar to mine? I'm tearing my hair out trying to figure out the cause of my woes, any help would be SO SO SO appreciated!!!

BTW, are you putting your timing cover back on or leaving it off? It looks fantastic off with all the pulleys painted, but will that have any possible adverse affect?

Cheers mate. Well done on the work you're doing to your beast!

John

Hi John,

The covers are off for the foreseeable future, the collective wisdom was to not bother. I think it was Henry Ford that said something along the lines of "Parts left off cost nothing to install and never need to be replaced".

With regard to your issues, Here's my thoughts.

Coil.
Needs to be one specifically for electronic ignitions. Mine's a Bosch transformer style coil similar to the new style GT40 coils.

Ignition module.
This is probably the culprit. Mine failed totally and suddenly with no warning signs. Other cars use the same system, the most common is the later Camiras, TD I think. These are a very common thing to fail. Any auto sparky will know what it is and will be able to get you one.

Distributor module.
The sensor in these can fail. The entire module is available as a part or some people have been able to replace just the sensor with a Jaycar equivalent Hall Effect Sensor.

Wiring.
Mine was a complete mess. Check the connector at the ignition module and the coil. I found that the connector on the distributor can hold water if the boot is cracked and this causes corrosion of the terminals. Clean all the plugs and sockets with contact cleaner and then give them a dose of WD40 to keep them dry.

I'd probably try and find a friend with a similar ignition system to swap bits over 'till you work out what's at fault.

I'd try cleaning all the plugs first, then replace the ignition module then the distributor module.

Sometimes you can get lucky and pick up an ignition module at the wreckers for $5.

Worst case scenario you can install a 1600 dizzy in there and dispatch the electronic system but I'd stick with it and sort yours our.

I'll send you some photos after I've had some dinner so you can identify the parts.

Pete

[Golfer]

Then the PM with the pictures...

As promised.

This is the module in my car. It's located in the rain tray, but I have no idea where to find a factory fitted one in a MK2 sorry. My Mk1 was fitted with MK running gear by a previous owner.

This is a genuine Meyle unit and has a square heatsink . The T shaped aluminium bracket is actually a Holden part which the deceased unit was mounted to. I reused it rather than drill more holes.

I purchased this unit from this ebay seller.
http://cgi.ebay.com/ebaymotors/Vw-Ra...6409QQtcZphoto

as well as a few other goodies including the distributor electronics.



This is the dead unit, there's no part numbers because they're stamped into that T shaped bracket. I think this is and original Camira part.



This is a unit I pulled from a Camira at the wreckers. I think this is a replacement Camira unit.


Close up of part number


Brand new Meyle distributor electronics, also from that ebay seller. I'll install these over easter if all goes well.



This is the plug on the distributor I was talking about.(With the blue heatshrink. Pull it off by pressing on that wire clip and pulling it straight up. The socket is cup shaped and holds water which causes corrosion. Clean it up with contact cleaner and WD40 also just pulling it on and off a few times helps to clean the contacts.








Hope this helps!

Pete

[Peter Jones]

Did you get it running ?

(And thanks for the praise!)

Pete

[Golfer]

So armed with a newfound knowledge of Mk2 electronics, thanks to Pete, I tackled the problem, and got lucky...

Having already checked my ignition wiring, plugs and bench tested the coil, I went straight to the ignition module (a part I didn't even know existed or it's whereabouts on my car). Located in the rain tray, sitting on top of a bracket and tucked away on it's own little heatsink, I managed to coax it (on it's bracket) out into the open, and then removed the harness and the two screws securing it to the heatsink...

The harness was full of gunk, dust and nastyness, and the retaining clip was rusted up. I cleaned up the clip, got out the Jaycar brand contact cleaner, and gave the harness a good working over. Brought that sucker up like new...

Then I pulled the module off the heatsink and found a big problem...

Underneath the module, where it's metal underside contacts with the heatsink, there was rust, and some strange looking crystals that looked like salt. I wiped away what I could, then sanded with 800 grit very gently to remove all the rust and cr@p off the bottom of the module (and off the heatsink)...

Then after cleaning the module very carefully and cleaning the electrical contacts, I applied some silver-based heatsink heat conduction compound (available from Jaycar) to the underside of the module, and returned it to it's heatsink, then the whole bracket back into the car...

Everything connected, all terminals and harnesses contact cleaned, so I turned the key...

Started within 2 seconds...

I would recommend checking the module to all of you. It can be inconvenient and embarrassing if it has a sudden failure on you, so prevention is better than a cure. Luckily my module doesn't seem to have sustained any long term damage from overheating, but not contacting properly with the heatsink could easily fry a module...

All my thanks to Peter Jones for taking the time to help a fellow dubber in need. You really are a very decent bloke...

Cheers all!!!
JHN

[Jmac]

Excellent job fellas - there used to be a tester box for them little units - you plugged it in and turn the vehicle over , you flick a button on the tester and it became the unit as a tester. worked great and back them it was common. Yeah im sure you have reinforced the fact that moisture , dirt and salt etc dont mix with electronics and electicity is a lazy thing and will take the easy way out .
Great work. Peter great to see genuine knowledge there, credit to you mate.
Jmac

[Jarred]

Pete defiantly is a smart bloke. Often knows the answers to the questions I havn't even asked yet!

Good on ya Pete.

[Peter Jones]

Glad to hear it's all up and running again

It's probably worth grabbing a new module when time and funds permit just to be on the safe side. This electronic stuff doesn't last forever.

The crystals you saw might have been dried up thermal grease or just oxdisation of the aluminium due to moisture and dissimilar metals in the heatsink, bolts and chassis.

Happy motoring!

Pete

[99gti]

Glad to hear the old girl is back up and running John.

Peter - nice work mate!

[Golf Loon]

Yeah nice one Pete and definately grab a new module to carry in the glovebox John. Glad you worked it out.