NG bad starting

kens_soup · 25-08-14, 08:15 AM

Is there anything common on the 2.3 NG that causes bad starting? I've just rought the car as a project so service wise I'm changing everything like plugs, dizzy cap, rotor arm etc.
It spins over for ages before it half heartedly fires, and once its going its lumpy, give it any throttle and it seems to cut out as if it's over-fuelling!

Coxy · 25-08-14, 08:20 AM

Idle Stabilization Valve maybe?

msh · 25-08-14, 08:32 AM

Why is it always oxygen sensor or ISV that gets blamed?

I'll bet it's receiving not enough fuel, not too much. If in doubt, when it stalls, remove spark plug and check if it's wet.

What's the idle speed when warm and does rev limiter kicks in @ 6,8k?

kens_soup · 25-08-14, 10:01 AM

I'll have a check! After idling a bit rough for a minute it does clear, run and idle fine!

PoloGaz · 05-09-14, 08:53 AM

Does the NG still have a cold start injector? If it does, try unplugging it. (blue plug on manifold) If engine starts better then you have leaky main injectors adding fuel to the cylinders when the engine is off.

It sounds a lot like how my 2.0 10v engine was running. Cranks for maybe 10-15 seconds then fires and runs like sh1t. But leave it for a week and it would fire immediately - all the fuel that leaked into the cylinders had evaporated.

You still got the B3 TDI as well?

msh · 05-09-14, 09:28 AM

How unplugging CSV removes fuel that has lowered compression in a cylinder?

Of course there is CSV - all KE-jet engines have it.

PoloGaz · 05-09-14, 09:50 AM

I dont understand your question.

John. · 05-09-14, 10:21 AM

Could be as simple as an air leak?

msh · 05-09-14, 10:56 AM

Quote:

Originally Posted by PoloGaz

I dont understand your question.

When one injector is leaking, engine starts on 3 or 4 pots [depending on pot count], because petrol has washed away oil, lowering compression in that pot. So how unplugging cold start valve makes this not to happen?

uxtcmenuts · 06-05-15, 06:29 PM

Did you ever figure out the problem mine dose the same thing.

05-09-14, 08:53 AM	#5
PoloGaz Grown up member Classic Audi Club Member Join Date: Aug 2012 Location: Manchester Posts: 362	Does the NG still have a cold start injector? If it does, try unplugging it. (blue plug on manifold) If engine starts better then you have leaky main injectors adding fuel to the cylinders when the engine is off. It sounds a lot like how my 2.0 10v engine was running. Cranks for maybe 10-15 seconds then fires and runs like sh1t. But leave it for a week and it would fire immediately - all the fuel that leaked into the cylinders had evaporated. You still got the B3 TDI as well? Last edited by PoloGaz; 05-09-14 at 08:55 AM.

25-08-14, 08:20 AM	#2
Coxy 4 Ring Mafia Classic Audi Club Member Join Date: Jul 2007 Location: on the side of a hill in Shropshire! Posts: 28,215	Idle Stabilization Valve maybe?

25-08-14, 08:32 AM	#3
msh 4 ring whore! Join Date: Jun 2008 Location: Rucava, Latvija Posts: 3,816	Why is it always oxygen sensor or ISV that gets blamed? I'll bet it's receiving not enough fuel, not too much. If in doubt, when it stalls, remove spark plug and check if it's wet. What's the idle speed when warm and does rev limiter kicks in @ 6,8k?

25-08-14, 10:01 AM	#4
kens_soup Grown up member Join Date: Jan 2014 Posts: 23	I'll have a check! After idling a bit rough for a minute it does clear, run and idle fine!

05-09-14, 09:28 AM	#6
msh 4 ring whore! Join Date: Jun 2008 Location: Rucava, Latvija Posts: 3,816	How unplugging CSV removes fuel that has lowered compression in a cylinder? Of course there is CSV - all KE-jet engines have it.

05-09-14, 09:50 AM	#7
PoloGaz Grown up member Classic Audi Club Member Join Date: Aug 2012 Location: Manchester Posts: 362	I dont understand your question.

05-09-14, 10:21 AM	#8
John. 4 ring whore! Classic Audi Club Member Join Date: Mar 2011 Location: Scottish Borders. Posts: 7,540	Could be as simple as an air leak?

06-05-15, 06:29 PM	#10
uxtcmenuts Grown up member Join Date: Jan 2015 Location: Indianapolis In, USA Posts: 73	Did you ever figure out the problem mine dose the same thing.