mk1 golf running and alternator issue

Hi guys, i have 83 GTI and am currently experiencing a few issues. firstly when i go to fire her up she fires but then cuts straight back out, she was running absolutely spot on and then one day this issue came up and i cannot for the life of me seem to work out why?? also my battery isnt charging,i had my alternator checked and re checked again and it is 100% ok and the battery is brand new..  could any kind person out there pleeeease help shed some light on this as i am so close to having her on the roadim not sure if it is linked but two days prior to these issues i had taken it to a garage to get the ignition timing all timed up etc correcly ready to be used daily.. and help would be MASSIVELY appreciated and thanks in advance..

If the car isn't running above 950-1100 RPM after starting then your alternator isn't charging the battery.  The throttle may have to be "blipped" to get the under frequency above the threshold to start charging.

Also the blue exciter wire feeds the Alternator the tickle to start the fields to charge, so that could also be the issue.

I would look at fuel delivery, as in Fuel Filter or fuel pump, as you didn't state if the car was Carbed, or Injected….

 

Thank you for your advice..it's fuel injected and I've checked and it's definitely getting fuel and also idles at above 1000Rpm and obviously higher when first started because of the auto choke..it fires up and dies instantly, I've tried planting the accelerator on start up to see if this help and it doesn't atallp

have you checked for air leaks? was it running ok after it came back from the garage as would need to be running to set the timing, does the battery light go out?

does the battery light come on with ignition then go out when started? if not the blue wire to the alternator is disconnected somewhere or the alt is shafted

Cheers for your responses guys..yeh the light does go out and I checked for earthing faults as I was advised that that could be the issue bit all seems good, and yeh it was working prior to the going to the garage, picked it up then the next day put a new fuel relay in and all the problems started,I swapped it back thinking this was the issue but it wasn't..I have no charge going to the battery yet alternator is 100% and like I said she fires and then just cuts out..initially it was just a charge fault as I kept her ticking over and found that the car died after about 10 mins of running and then the cutting out issue began..thanks for all your help so far guys

alright cool, its probably not the alternator then.

have a listen out for the fuel pump, it should run while the engine is cranking, and see if it carrys on running for a couple seconds after the engine cuts or not.

Also does the rev counter work? if not then the fuel relay may not be getting a rev pulse which triggers it to keep it running after the engine has fired.

if you swap a 17/18/100 relay to the fuel pump socket your fuel pump should be on all the time with the ignition which can help with troubleshooting.

I had a similar issue with cutting out, on my 1984 gti convertible. Changed the hall sender cured the problem . The Haynes manual tells you how to test the hall sender

Cutting out after 10 minutes?…
So for the first few minutes everything is fine?

For a test of your grounds, take a pair of battery jumper cables, and attach the red pair from the negative battery post to good frame ground ie: the nuts holding the strut tower.

Take the Black pair and attach that from the negative battery post to the Engine/Tranny.

Start the car and check to see that the battery is getting 13.5V.  This would be an indication that the Alternator is putting out the correct voltage, but not a true test of the current it is putting out.  After hard starts or continious run of the starter, you can drain a marginally good battery and it can't take the re-charge.  If your battery hasn't been tested off the car, then it might be wise for you to remove the Battery and Alternator and have it tested to verify that it is 100percent functional and that cells aren't shorting out under load.

Grounding issues which is why I ask that you jumper them is another condition which can cause issues on a 30 year old car,  I usually replace the grounds on a new to me used car as I have been burnt before by them.

The car cutting out and dieing after 10 minutes of running could be a battery issue as well.  I would suspect the fuel pump for over heating at a 10 minute mark, and is this fuel injected or Carbed?

There are also suspect aftermarket fuel pump relays, that have caused similar issues as they over heat get cold solder joints, stop working then a few minutes later the cool enough to start the car, then heat up and die.

One test would be to Jumper the relay out as a test to see if the issue is the relay or the fuel pump.  

Over here those with CIS injection usually carry a know good spare in the boot or glove box, the Digifant cars don't seem to have the same issue with overheating Fuel pump Relays.

This sure sounds electrically suspect so getting the battery tested out of the car as well as the alternator wouldn't be a bad first step.

Hi guys thanks for all your help, the car is now working spot on..I changed the fuel relay to an official VW one although the other one was brand new and was the best I could get without ordering from Germany and I also cleaned and checked all major earths and found a few gremlins there..all good is now tho and once gain thank for everyone's help and advice