Recently Acquired MK2 GOLF w/2L conversion stalling and starting problem

[courtz1976-2dr]

Hi there Alkl,

I a,m hoping that someone may be able to shed some insight to a very frustrating problem that I have had on a number of occasions.

recently acquired a very nice mk2 with 2.0 conversion and drove from Melbourne to qld no worries.

3 times now it has just stopped at various cruising speeds as if no spark, triple checked all wiring and only recently made this discovery

The car refuses to start when exhibiting this issue, there is spark but only weak spark..

When checking all wiring everything checks out (signal to ecu, power @ coil, signal to coil etc PWR to ecu) but after trying for 2 days to get the thing to start, I plugged in a dizzt from a 1.8, spun it by hand and got fat spark, THEN plugged in currently installed dizzy and the car started first time..

What could be causing this,

HALL SENDER???
TRANSISTOR IN ECU???
IGNITION MODULE???

The car has the siemens ecu and associated wiring (not sure of original donor) I do also have complete wiring harness and ecu for dig II system and was wondering if this can be ustilised for the 2.0L


ANY HELP OR SUGGESTIONS WELCOME - IT HAS REQUIRED TOWNING ON3 OCCASIONS NOW AND AM RELUCTANT TO DRIVE it is suh a beautiful little car and to have it sit is extremely frustrating.

*********EDIT*********

What I frogot to mention in the original post is the there IS spark when this happens it is just it is not as "fat" as you would expect sort of like there is not as much HT power - the situation stayed the same for days of troubleshooting wires etc. I originally thought I have it sorted as I replaced the ignition switch and it cam to like again. but it has happened twice since, once I left it for a while and came back and it started the most recent it persisted until the dizzy swapover (it wasnt replaced but used by hand for testing - from a 1.8 engine) and has run and started every time since, I have even left it running for about an hour with no issues. Also when it does happen the fuel pumps still fire on ignition etc the oinly thing that is common on all occasions is the "fatness of the spark. sort of like how you have a ballast resit-or on older type coils that give you the fatter spark for starting but lesser spark when running.

Any other suggestions as I could throw money towards ECU ignition module and dizzy and potentially be at step one. I need to know if there is anything that would change he actual ht side based on any other inputs from the system?


I cannot be stranded again, or I could carry the dissy asuming this will resolve the issue, but I cannot understand how a hall sender would give ifluence to the ht spark. I am nearly at taking it back to the 1.8 that also cam with...GRRR how frustarating,


I look forward to any insights that may shed some light on this predicament.

Cheers and Regards,
Courtney.

[sports racer]

There are a lot of sensors on the engine and if they have a loose connection or a broken wire they can cause hell.

On mine whenever it started to run rough I unplugged every connection and plugged it back in and it would be fine for a few more months. Eventually I tracked it down to a fraying wire on one of the temperature sensors.

[h100vw]

Hi there Alkl,

I a,m hoping that someone may be able to shed some insight to a very frustrating problem that I have had on a number of occasions.

recently acquired a very nice mk2 with 2.0 conversion and drove from Melbourne to qld no worries.

3 times now it has just stopped at various cruising speeds as if no spark, triple checked all wiring and only recently made this discovery

The car refuses to start when exhibiting this issue, there is spark but only weak spark..

When checking all wiring everything checks out (signal to ecu, power @ coil, signal to coil etc PWR to ecu) but after trying for 2 days to get the thing to start, I plugged in a dizzt from a 1.8, spun it by hand and got fat spark, THEN plugged in currently installed dizzy and the car started first time..

What could be causing this,

HALL SENDER???
TRANSISTOR IN ECU???
IGNITION MODULE???

The car has the siemens ecu and associated wiring (not sure of original donor) I do also have complete wiring harness and ecu for dig II system and was wondering if this can be ustilised for the 2.0L


ANY HELP OR SUGGESTIONS WELCOME - IT HAS REQUIRED TOWNING ON3 OCCASIONS NOW AND AM RELUCTANT TO DRIVE it is suh a beautiful little car and to have it sit is extremely frustrating.


I look forward to any insights that may shed some light on this predicament.

Cheers and Regards,
Courtney.

Only really a couple of things that can stop it dead. Dissy/hall sender is one. Often comes back once the car cools down for a while. Gets worse and then stops almost like clockwork after 10 minutes or a certain running time.

Other constant failures are the ECU relay and fuel pump relays.

I have posted about these in the past as I have fixed a good handful of GTIs in the UK. Take the lid of the relays and look at the solder joints, most likely one or more will be dry and dull grey. Not shiney silver.

Re working the joints will bring it back to life. Sometime you need to desolder them and use flux to get a proper joint.

https://www.google.com.au/webhp?sour...#q=dry%20joint

Gavin

[dubstar]

Fuel Pump Relay. Buy a new one (not second hand)

[Bora Sport]

Sounds to me like the ECU relay. When driving it will stop just like the ignition has been turned off. Usually if you turn the ignition of it will start straight away.

[courtz1976-2dr]

Only really a couple of things that can stop it dead. Dissy/hall sender is one. Often comes back once the car cools down for a while. Gets worse and then stops almost like clockwork after 10 minutes or a certain running time.

Other constant failures are the ECU relay and fuel pump relays.

I have posted about these in the past as I have fixed a good handful of GTIs in the UK. Take the lid of the relays and look at the solder joints, most likely one or more will be dry and dull grey. Not shiney silver.

Re working the joints will bring it back to life. Sometime you need to desolder them and use flux to get a proper joint.

https://www.google.com.au/webhp?sour...#q=dry%20joint

Gavin

What I frogot to mention in the original post is the there IS spark when this happens it is just it is not as "fat" as you would expect sort of like there is not as much HT power - the situation stayed the same for days of troubleshooting wires etc. I originally thought I have it sorted as I replaced the ignition switch and it cam to like again. but it has happened twice since, once I left it for a while and came back and it started the most recent it persisted until the dizzy swapover and has run and started every time since, I have even left it running for about an hour with no issues. Also when it does happen the fuel pumps still fire on ignition etc the oinly thing that is common on all occasions is the "fatness of the spark. sort of like how you have a ballast resit-or on older type coils that give you the fatter spark for starting but lesser spark when running.

Any other suggestions as I could throw money towards ECU ignition module and dizzy and potentially be at step one. I need to know if there is anything that would change he actual ht side based on any other inputs from the system?


I cannot be stranded again, or I could carry the dissy asuming this will resolve the issue, but I cannot understand how a hall sender would give ifluence to the ht spark. I am nearly at taking it back to the 1.8 that also cam with...GRRR how frustarating,

[blis]

Does the engine look like this?

[gldgti]

I had a similar issue on a mk1 1.6 once - I tried everything to get it to work properly, but the darned thing did have spark - just really weak at times like you describe.

I changed the plugs and it fixed it :shrugs:

[JAYISK]

Hey mate,
you still having the same problem or did you work it out?

[dubsquad]

Had a similar problem with a mk3 GTI a few years back. 2.0 8v 2e engine used to cut out randomly but would start again about 1-2 hrs later. Changed ECU relay, coil, plugs, leads, dizzy cap, fuel pump and pump relay and it still did it. Ended up being the distributor. Replaced with a 3 terminal one out of a 1.8 8v polo. Never had the issue again.

Cheers
Leigh


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