I'm a click away... How to get codes from my 940

[mhuk]

Morning folks,

My 940 is having issues. When I am coming down from high revs/speed to a stop I change down the gears as normal. However when I have the clutch down the revs will drop and engine stalls. This will happen 15 or so times on a 60 mile drive.

It will restart OK and idle but sometimes it idles low and stalls again. It should be around the 800rpm.

I found the O2 sensor was loose so did that up and still the same but for some reason it does not seal down on the washer. It's a homemade (it' not ****ty) 3" dp.

The issues started when I changed the airbox to a cone filter and removed the PCV heater. I put it back on and went for a drive and all was good.

Next time I drive the car it's playing up.

I only take the car out every 2 or 3 weeks tbh.

I also found one of the spark plugs had unscrewed it's top hat which thankfully was in the spark plug lead. I put that back on. When I got the car it had 3 of those top hats missing. I'm not sure how it would even unscrew?

I had a OBD breakout box a friend has given me but I can't find the link on how to test the car. Anyone have it?

Cheers

Martin

[Clan]

Originally Posted by mhuk

Morning folks,

My 940 is having issues. When I am coming down from high revs/speed to a stop I change down the gears as normal. However when I have the clutch down the revs will drop and engine stalls. This will happen 15 or so times on a 60 mile drive.

It will restart OK and idle but sometimes it idles low and stalls again. It should be around the 800rpm.

I found the O2 sensor was loose so did that up and still the same but for some reason it does not seal down on the washer. It's a homemade (it' not ****ty) 3" dp.

The issues started when I changed the airbox to a cone filter and removed the PCV heater. I put it back on and went for a drive and all was good.

Next time I drive the car it's playing up.

I only take the car out every 2 or 3 weeks tbh.

I also found one of the spark plugs had unscrewed it's top hat which thankfully was in the spark plug lead. I put that back on. When I got the car it had 3 of those top hats missing. I'm not sure how it would even unscrew?

I had a OBD breakout box a friend has given me but I can't find the link on how to test the car. Anyone have it?

Cheers

Martin

regarding the unstable idle you need to clean the inside of the throttle body and flap from carbon , this usually does the trick .
If not also check the throttle position sensor/microswitch for correct operation , this switches in the auto idle speed control when the throttle is closed .

[loki_the_glt]

PM sent with my instructions on using the break-out box style code reader.

[mhuk]

Thanks guys. I got the PM and replied. I'll clean that.

[TonyS9]

Sounds like the dump valve isn't working. Maybe torn/stuck, pipe missing/blocked. Its the triangular thing bolted into the side of the turbo.

If you don't dump the pressure it won't idle after using the turbo. If you try reving it a bit for about 5s just above idle, it should idle then ater that. The pressure then has a chance to dissipate. Closed throttle assumes a certain amount of air flow, but if you have pressure you have too much air and a weak mixture, weak enough to stall the engine. Open throttle is much richer and can cope better if you have no dump.

And it won't show a code, the ECU doesn't have enough time to cycle the mixture to decide that the O2 feedback can't be brought into control.

Actually rereading, the dirty throttle body could be responsible (for similar weak mixture reasons), but consider the dump valve too.

[mhuk]

Thanks guys.

I not had time to test the O2 but it was refitted as is with cleaned threads. It still stalls from high revs from time to time.

I did have the idle valve off yesterday for cleaning and wanted to clean the throttle but it rained down hard so gave up.

Here is the idle valve in my ultrasonic cleaner. It's cleaned up so well I can read clearly the part numbers on the inside. Turn your headphones down!!

[YOUTUBE]https://www.youtube.com/watch?v=_6H0LAbR3Aw[/YOUTUBE]

I hope it goes part way to resolving the issue. Next will be the throttle. I already have a spare which was cleaned to death so might just stick that on.

[Clan]

Originally Posted by mhuk

Thanks guys.

I not had time to test the O2 but it was refitted as is with cleaned threads. It still stalls from high revs from time to time.

I did have the idle valve off yesterday for cleaning and wanted to clean the throttle but it rained down hard so gave up.

Here is the idle valve in my ultrasonic cleaner. It's cleaned up so well I can read clearly the part numbers on the inside. Turn your headphones down!!

[YOUTUBE]https://www.youtube.com/watch?v=_6H0LAbR3Aw[/YOUTUBE]

I hope it goes part way to resolving the issue. Next will be the throttle. I already have a spare which was cleaned to death so might just stick that on.

What was the magic liquid you used though? :-)

[mhuk]

https://www.amazon.co.uk/Gunk-6868-U...3820643&sr=8-1

Works wonders. Cheaper then the gunk gunk stuff.