2.2 KU starting issue - Page 4

quattrostyle · 26-06-17, 07:23 AM

To Mark and Simon, I've done pretty much on the car so far from a drivetrain refresh incl. clutch up to the head gasket, valve stem seals etc.

List of what has been done relating to the fuel and ignition system:
- spark plugs
- rotor + ditributor cap
- fuel filter
- injector seats
- injector O-rings

Ignitioin timing is right up the line it needs to be at on the flywheel, CO has been set correctly, but the HC value is very high! Maybe that points to the injectors? Which I'd like to renew anyway.

I had the cold start injector unplugged and it made no difference.

If it's likely to be the injectors, where would be best to get them? They're not exactly cheap.

The wheels are the deeper dish version of the Ronal R8 in 7x15, ET37 I believe.

simons2 · 26-06-17, 07:39 AM

I changed a set of plugs and leads once for a new set and one of the new ones was breaking down when hot.
Have you done a compression test?
If poss remove the injectors sit in jam jars and check there all delivering the same amount. On the KU metering head you can adjust the flow of each injector by turning the allen key on the metering head I can't remember if the metering head is the same on the KV (don't think it is)
Ebay, seem them listed on there although I think the KV injector is different to the KU one.

M4rkp · 26-06-17, 09:01 AM

If you have HIGH HC that means that unburnt fuel is being thrown out of the exhaust - but as you say your CO level is good ( what is it btw?) then it sounds like you have a vacuum/air leak and you are compensating for unmetered air with the mixture screw.

Check ALL of the small bore vacuum hoses - once you have checked them, check them again - ideally with a mityVac. I would recommend disconnecting the vacuum line that goes to the diff locks and plug the feed line, this will discount anything that isn't in the engine bay.

Make sure the thermo valve on the RHS of the block is working and also check that the throttle switch on the inlet manifold is wired and working.

quattrostyle · 10-07-17, 06:40 PM

All vaccuum are new, in the engine bay that is:hand. I'll have a look for a mityVac.
Co is set about 2.5 I believe? Had the data at hand when adjusting it.

How to be sure if the thermo valve is working correctly?

M4rkp · 11-07-17, 07:39 AM

Quote:

Originally Posted by quattrostyle

How to be sure if the thermo valve is working correctly?

You mean the 2 pronged device on the back of the head?

Unscrew it and see if you can blow through it - ideally you need to see if it holds vacuum using a MityVac.

Get a cup of very hot water and immerse the metal screwthread in the water - eventually you should hear a 'click' - this is the bi-metallic strip closing. Now see if it will hold vacuum again.

It will only hold vacuum on one occasion - cant remember if its hot or cold.

Colin Aitchison · 11-07-17, 10:03 AM

The bi-metal vac switch your are talking about can be closed when cold or open when cold,
depending on your engines, look at the part number stamped into the brass and find out if you have the correct bi-metal vac switch for your car fitted.

quattrostyle · 12-07-17, 06:37 PM

Quote:

Originally Posted by M4rkp

You mean the 2 pronged device on the back of the head?

Unscrew it and see if you can blow through it - ideally you need to see if it holds vacuum using a MityVac.

Get a cup of very hot water and immerse the metal screwthread in the water - eventually you should hear a 'click' - this is the bi-metallic strip closing. Now see if it will hold vacuum again.

It will only hold vacuum on one occasion - cant remember if its hot or cold.

I mean the one you meant

I also read someone who deleted the fuel accumulator near the pump for a one way valve with good results. Tempted to try that as well.
Don't have much time to work on the car unfortunately and previous fights with the KV in my former coupe quattro have not been promising

26-06-17, 07:23 AM	#31
quattrostyle 4 ring whore! Classic Audi Club Member Join Date: Feb 2010 Posts: 2,188	To Mark and Simon, I've done pretty much on the car so far from a drivetrain refresh incl. clutch up to the head gasket, valve stem seals etc. List of what has been done relating to the fuel and ignition system: - spark plugs - rotor + ditributor cap - fuel filter - injector seats - injector O-rings Ignitioin timing is right up the line it needs to be at on the flywheel, CO has been set correctly, but the HC value is very high! Maybe that points to the injectors? Which I'd like to renew anyway. I had the cold start injector unplugged and it made no difference. If it's likely to be the injectors, where would be best to get them? They're not exactly cheap. The wheels are the deeper dish version of the Ronal R8 in 7x15, ET37 I believe.

26-06-17, 07:39 AM	#32
simons2 Grown up member Classic Audi Club Member Join Date: Jun 2012 Location: ireland Posts: 291	I changed a set of plugs and leads once for a new set and one of the new ones was breaking down when hot. Have you done a compression test? If poss remove the injectors sit in jam jars and check there all delivering the same amount. On the KU metering head you can adjust the flow of each injector by turning the allen key on the metering head I can't remember if the metering head is the same on the KV (don't think it is) Ebay, seem them listed on there although I think the KV injector is different to the KU one.

26-06-17, 09:01 AM	#33
M4rkp Grown up member Classic Audi Club Member Join Date: Feb 2013 Location: Sometimes Roberttown - sometimes Surrey Posts: 194	If you have HIGH HC that means that unburnt fuel is being thrown out of the exhaust - but as you say your CO level is good ( what is it btw?) then it sounds like you have a vacuum/air leak and you are compensating for unmetered air with the mixture screw. Check ALL of the small bore vacuum hoses - once you have checked them, check them again - ideally with a mityVac. I would recommend disconnecting the vacuum line that goes to the diff locks and plug the feed line, this will discount anything that isn't in the engine bay. Make sure the thermo valve on the RHS of the block is working and also check that the throttle switch on the inlet manifold is wired and working.

10-07-17, 06:40 PM	#34
quattrostyle 4 ring whore! Classic Audi Club Member Join Date: Feb 2010 Posts: 2,188	All vaccuum are new, in the engine bay that is:hand. I'll have a look for a mityVac. Co is set about 2.5 I believe? Had the data at hand when adjusting it. How to be sure if the thermo valve is working correctly?

11-07-17, 10:03 AM	#36
Colin Aitchison Senior Member Classic Audi Club Member Join Date: Dec 2013 Location: Back home in Tillicoultry Posts: 1,308	The bi-metal vac switch your are talking about can be closed when cold or open when cold, depending on your engines, look at the part number stamped into the brass and find out if you have the correct bi-metal vac switch for your car fitted.