G60 | No spark | Toasted ECU? | SOLVED

[EssexG60 1]

Ok so the story so far……………….

New Battery (Bosch S5)
New Fuel Pump including sender unit
Siphoned out all old fuel
Clean up of fuel tank
New fuel (20 litres)
New Spark plugs (Bosch Super Plus) + fogging oil applied to all cylinders
 

Fuel Pump relay connector:
Check pin 30 - Constant 12v present
Check pin 87 - Signal working towards Fuel Pump when bridged via 30
Check pin 86 - 12v present upon ignition
Check pin 85 - "- 0v" reading present upon cranking, which I understand is correct?

Fuel Pump Relay
New relay installed
Proceeded to turn the car but still no explicit/loud sounds of the Fuel pump priming however fuel is being carried upon cranking of the engine, tested via checking fuel line to injectors.

Distributor/Spark Plugs
Is spark present at spark plugs - No
Is spark present on King lead from Ignition coil - No

Ignition Coil
Removed Ignition coil and correct ohms present when testing with multi meter.
Primary coil 0.6 Ohms (must be 0.5 to 0.7 Ohms according to Bentley) - Correct
Secondary coil 3600 Ohms (must be 3000 to 4000 Ohms according to Bentley) - Correct
Check continuity towards Ignition coil (Green wire) from ECU (Pin 25) - Yes
Check voltage to Ignition coil, should be 12v - Yes

From this I gather the Ignition coil is "functioning".

Hall Sensor Harness
Check continuity towards Hall sensor harness (Red/Black) from ECU (Pin 😎 - Yes
Check continuity towards Hall sensor harness (Green/White) from ECU (Pin 18)- Yes
Check voltage to Hall sender harness upon ignition, should be 12v - No
Pin 1 = Ground
Pin 2 = Should be under 12v and fluctuate towards 0 when cranking
Pin 3 = 12v - No

ECU relay connector:
Check pin 30 for 12v - Yes
Check pin 86 for 12v at Ignition - Yes
Check pin 87 for Voltage? Yes on ignition

ECU Relay:
Connect pin 85 to negative - Yes
Connect pin 86 to positive - Yes
Does it click, is coil energizing? - Yes

If Yes,
Connect 85 to negative
Connect 86 to positive
Check continuity over 30 and 87 with Multi meter - Working
 

ECU
Check pin 1 on ECU for 12v at ignition - Yes (Starter power)
Check pin 3 on ECU for 12v at ignition - Yes (Fuel Pump Relay)
Check pin 12 on ECU for 12v at ignition - Yes (Injector Power)
Check pin 14 on ECU for 12v - Yes (Power from Control Unit Relay)
Check pin 22 on ECU for 12v at ignition - Yes (Idle stabilizer valve)
Check pin 25 on ECU for 12v - Yes (To Ignition Coil)

 

Fuel Pump Relay: New relay installed, Continuity present, Voltage present. Pump still not priming
Ignition Coil: Continuity present, Voltage present.
Hall sender harness: Continuity present, no Voltage present - should this be coming from the ECU?
ECU relay: Working as far as I can see but will change for a new one as it was already on order and in the post.
ECU: All checked pins receive inbound voltage, however I have no further points of reference to check whether the ECU is distributing the signal to the various components.

In addition still no Tachometer readings along with fuel on dash.

Does all this point to a faulty ECU? 😐
Any suggestions or corrections welcomed

Kr

Dee

[_Matt_ 32]

Extensive checking! What about the rotor arm on the distributor itself? On my mk2 16v I did similar checks with voltage etc but found the rotor arm was a touch loose so when it span it didn't hit the contacts in the cap.

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[Dox 23]

Any old alarms / immobilisers fitted?

Edited October 18, 2022 by Dox

[EssexG60 1]

10 hours ago, MJA said:

Extensive checking! What about the rotor arm on the distributor itself? On my mk2 16v I did similar checks with voltage etc but found the rotor arm was a touch loose so when it span it didn't hit the contacts in the cap.

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Hey Matt, Dizzy is spinning but that's about it in terms of checking as there is no spark I need to be sure the Ignition coil is generating that and therefore being present at the end of the King HT lead.

10 hours ago, Dox said:

Any old alarms / immobilisers fitted?

 Hi Dox,

Yes there is an aftermarket Toad immobiliser.
Have tested with it enabled and there is no tickover, once disabled the car does crank so I think we are ok on that front 🙂

In addition to yesterday I swapped over the HT leads which was something I was going to do anyway.
Also managed to source a new Ignition Coil for testing but still the same issue.

My worry is that the Hall sensor not getting power has something todo with this whole palava!!
Looking at the wiring diagrams, the hall sensor obtains power from the ECU at pin 8 but I am seeing nothing, also checked the ground which seems ok.

I have also looked at the ECU, no obvious defects I can see but I am not pro.

Any ideas welcomed?

[EssexG60 1]

Just a thought, does the Ignition Switch also play a part in the issues I have faced so far?
That has not been replaced.

Accessories do turn on at ignition aswell as the warning lights but I assume that is power directly from the battery.
Does the ignition switch also send a signal to the ECU for it to fire up the Coil?


 

[Dox 23]

Ign sw will power up the ECU via the relay and you have power?

[EssexG60 1]

2 hours ago, Dox said:

Ign sw will power up the ECU via the relay and you have power?

I have 12v power at the below ECU pins:

Check pin 1 on ECU for 12v at ignition - Yes (Starter power)
Check pin 3 on ECU for 12v at ignition - Yes (Fuel Pump Relay)
Check pin 12 on ECU for 12v at ignition - Yes (Injector Power)
Check pin 14 on ECU for 12v - Yes (Power from Control Unit Relay)
Check pin 22 on ECU for 12v at ignition - Yes (Idle stabilizer valve)
Check pin 25 on ECU for 12v - Yes (To Ignition Coil)

Based on the below, my hunch is power in from the ign sw to the ECU is via pin 1:

I hope I'm on the right track!!

 

Edited October 18, 2022 by EssexG60

[Dox 23]

So you’re missing 12v+ at pin 8 on the ecu and it’s corresponding pin 3 on the hall sensor?

Edited October 18, 2022 by Dox

[EssexG60 1]

5 minutes ago, Dox said:

So you’re missing 12v+ at pin 8 on the ecu and it’s corresponding pin 3 on the hall sensor?

Correct, I can double check again but I only got voltage on the below pins on the ECU when tested the other day.

pin 1 (Starter power)
pin 3 (Fuel Pump Relay)
pin 12 (Injector Power)
pin 14 (Power from Control Unit Relay)
pin 22 (Idle stabilizer valve)
pin 25 (To Ignition Coil)

 

Was just checking Bentley and on testing I barely got over 11 mv ... which currently points to ECU.
Continuity checks ok on pins 1 and 2 of harness also.

 

[Dox 23]

If this was mine it would be too tempting to jerry rig a fused 12v+ to pin 3 on the hall sensor - this would be at MY risk.

 

Back in the day when G60 engine conversions were popular I'm sure G60 engines could be fitted to 88 onwards 8V PB engined MK2 Golfs (NOT earlier K-jet) cars using the base cars loom and adding a few wires to the ecu plug? My logic therefore would be an 8V ECU from a late MK2 Golf would start a G60 and allow it to idle?

 

This would be at MY OWN risk, I'm only mumbling this so you can do your own research before taking a leap of faith.

 

If in doubt ignore my ramblings

[EssexG60 1]

If this was mine it would be too tempting to jerry rig a fused 12v+ to pin 3 on the hall sensor - this would be at MY risk.
 
Back in the day when G60 engine conversions were popular I'm sure G60 engines could be fitted to 88 onwards 8V PB engined MK2 Golfs (NOT earlier K-jet) cars using the base cars loom and adding a few wires to the ecu plug? My logic therefore would be an 8V ECU from a late MK2 Golf would start a G60 and allow it to idle?
 
This would be at MY OWN risk, I'm only mumbling this so you can do your own research before taking a leap of faith.
 
If in doubt ignore my ramblings

Thanks for the input Dox.
Ideal situation would be me testing a working ecu which I can get my hands on lol.

I may have to get my current tested or find a used one which I can test before purchase

Power to the hall sensor isn’t the old pin not getting power, there are yet other pins also.

Any spare G60 ecus going around ?


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[Crasher 3]

ECU failure is extremely rare BUT when I was working on a lot of PG engines I did experience a number of ECU failures where the internal ignition amplifier failed.

[EssexG60 1]

58 minutes ago, Crasher said:

ECU failure is extremely rare BUT when I was working on a lot of PG engines I did experience a number of ECU failures where the internal ignition amplifier failed.

Car has been sitting for years but that doesnt explain how it could have failed after all this time...
I can only but try 🙂

Does the G60 have an ignition amplifier?

 

[Crasher 3]

The last one I had this on I could not get a used or new ECU, I sent it to BBA Reman and they sent it somewhere else and it came back fixed which is a rare thing with BBA... You can still get the EG and H suffix ECU's from VW Classic https://www.volkswagen-classic-parts.com/catalog/en_uk/search?q=037906023h

Edited October 19, 2022 by Crasher

[EssexG60 1]

3 hours ago, Crasher said:

The last one I had this on I could not get a used or new ECU, I sent it to BBA Reman and they sent it somewhere else and it came back fixed which is a rare thing with BBA... You can still get the EG and H suffix ECU's from VW Classic https://www.volkswagen-classic-parts.com/catalog/en_uk/search?q=037906023h

Thanks for the details.
I have managed to source an ECU which should arrive by the weekend.
No promise that the ECU itself will be "perfect" as it is used but definitely worth a shot at this stage.

Failing that I may require a trip to see the gents at Corrado Graveyard.

 

Fun and games 🙂

 

[EssexG60 1]

Finally some traction today....

New ECU installed and the car has fired up into life!!
Due to the weather couldn't keep it running for long but there is life ...... a bit of white smoke which we will need to look into however we have progress...

 

😉