Rough Engine Idle When Cold (Diesel)

[ajf]

Hi Guys, from a cold start my engine runs really rough like a miss fire when the engine revs are on idle. If I pull away and increase the revs it's fine. It's also fine after warming up slightly. Has anybody else come across this problem. My engine has completed 161.000 miles and I have recently had the EGR valves cleaned and had a terraclean?

[Jaguar Owners Club]

Do any warning lamps come on during this time?

[ajf]

Hi Trevor. No, no warning lights come on at all. As I said, once I pull away and under revs she's as sweet as! Tony

[Jaguar Owners Club]

possibly then the throttle housing is suffering from a build up of carbon.

The Terraclean treatment I believe may not have covered that part of the intake system.

If that is the case it is not too difficult to remove the throttle housing and clean it with Carb Cleaner.

[ajf]

Thanks Trevor, I will look into getting the throttle housing cleaned. If this cures the problem i'll post the result.

[White Wing]

Hi,    sorry to ask this and sound like an idiot but I thought diesel cars did not have a throttle body? I thought they were controlled directly by the amount of fuel injected?

I know petrol engines use a throttle body to control the airflow which in turn regulates the revs

Please correct me if I am wrong?

[Old Peter]

Hi John,

 

I looked at the internet for some images of the throttle body, and found some.

 

The 2.7 diesel has got a throttle body.  A new one would cost over £100.

 

Worth cleaning it.

 

Peter.

[White Wing]

Hi John,

 

I looked at the internet for some images of the throttle body, and found some.

 

The 2.7 diesel has got a throttle body.  A new one would cost over £100.

 

Worth cleaning it.

 

Peter.

Hi Peter,   

Well thats something I have learned today!  My only experience with diesels are my rover 75's and they dont have a throttle body.

Thanks for putting me right there ;)

John.