940 judders on start

TurnipSpeed · Jul 28th, 2020, 18:02

Hi, still got probs with 940 2.3lpt.
On starting, the car judders as if running on two or three cylinders,
But runs fine when warm.
A little hesitant to start, and sometimes a petrol smell.
Would the iacv or pump give these symptoms?
The car is on 189000 miles, and still pulls like a train.
Any advice?
Thanks.

griston64 · Jul 28th, 2020, 19:28

How old are the leads ?

TurnipSpeed · Jul 29th, 2020, 09:29

Hi, the leads are about 24 years old!

griston64 · Jul 29th, 2020, 11:19

I would order a new set of Bourgicord leads then

TonyS9 · Jul 29th, 2020, 12:25

Normally a cold start missfire is not related to leads, but they should be replaced. Rotor arm and distributor cap should at least be inspected and cleaned. Same for spark plugs.

The idle air valve or pump are unlikely to be the problem, fuel pressure regulator is more likely, but wouldn't usually change with warm/cold.

Sounds more to me like :

-a coolant leak into the cylinder - is there any coolant loss?
-Low compression - can you check this?
-Small Air leak near that cylinder - leaky inlet gasket

TurnipSpeed · Jul 29th, 2020, 13:00

Hi, TonyS9,
Yes, there has been regular coolant loss for months.
Signs of “spray” on the under tray, but no other visible signs of a leak.
The radiator was replaced recently, but that made no difference to the slow coolant loss.
It’s okay for a few days, then the level drops below min over about 100 miles.

TonyS9 · Jul 29th, 2020, 14:44

If the radiator was changed a common issue is that the coolant was topped up with water instead of water+additive while it was leaking. This dilutes out the additive causing galvanic corrosion between the steel block and the aluminium head, eventually damaging the head gasket.

If you had a borescope you could take the plugs out and check for fluid in the cylinders after sitting overnight.

Jul 28th, 2020, 18:02	#1
TurnipSpeed TurnipSpeed Last Online: Jul 7th, 2023 15:53 Join Date: Jun 2012 Location: Peterlee	940 judders on start Hi, still got probs with 940 2.3lpt. On starting, the car judders as if running on two or three cylinders, But runs fine when warm. A little hesitant to start, and sometimes a petrol smell. Would the iacv or pump give these symptoms? The car is on 189000 miles, and still pulls like a train. Any advice? Thanks.

Jul 28th, 2020, 19:28	#2
griston64 Premier Member Last Online: Today 19:22 Join Date: Jul 2012 Location: Lenzie	How old are the leads ? __________________ V70 D5 SE Geartronic 215bhp Saville Grey 2012MY 940 LPT Manual 1996 740 SE 1990

Jul 29th, 2020, 11:19	#4
griston64 Premier Member Last Online: Today 19:22 Join Date: Jul 2012 Location: Lenzie	I would order a new set of Bourgicord leads then __________________ V70 D5 SE Geartronic 215bhp Saville Grey 2012MY 940 LPT Manual 1996 740 SE 1990

Jul 29th, 2020, 09:29	#3
TurnipSpeed TurnipSpeed Last Online: Jul 7th, 2023 15:53 Join Date: Jun 2012 Location: Peterlee	Hi, the leads are about 24 years old!

Jul 29th, 2020, 12:25	#5
TonyS9 Premier Member Last Online: Jun 16th, 2024 19:56 Join Date: Jul 2009 Location: Holywood	Normally a cold start missfire is not related to leads, but they should be replaced. Rotor arm and distributor cap should at least be inspected and cleaned. Same for spark plugs. The idle air valve or pump are unlikely to be the problem, fuel pressure regulator is more likely, but wouldn't usually change with warm/cold. Sounds more to me like : -a coolant leak into the cylinder - is there any coolant loss? -Low compression - can you check this? -Small Air leak near that cylinder - leaky inlet gasket

Jul 29th, 2020, 13:00	#6
TurnipSpeed TurnipSpeed Last Online: Jul 7th, 2023 15:53 Join Date: Jun 2012 Location: Peterlee	Hi, TonyS9, Yes, there has been regular coolant loss for months. Signs of “spray” on the under tray, but no other visible signs of a leak. The radiator was replaced recently, but that made no difference to the slow coolant loss. It’s okay for a few days, then the level drops below min over about 100 miles.

Jul 29th, 2020, 14:44	#7
TonyS9 Premier Member Last Online: Jun 16th, 2024 19:56 Join Date: Jul 2009 Location: Holywood	If the radiator was changed a common issue is that the coolant was topped up with water instead of water+additive while it was leaking. This dilutes out the additive causing galvanic corrosion between the steel block and the aluminium head, eventually damaging the head gasket. If you had a borescope you could take the plugs out and check for fluid in the cylinders after sitting overnight.

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