VAGCOM Injector Readings

[MopedMan]

Hi all,

Recently, upon starting my car in the mornings, it idles rough for a minute or 2, and when accelerating, there's a slight diesel knock on light acceleration with some lumpiness.

If I give it more throttle, it's as it should be. Once the car has warmed up even the slightest amount, it's ok

So, I'm assuming it may be the injectors on the way out, but would like to verify it. Side note, there is no smoke present.

Car is a 1.6 TDi 110hp.

 

[MeltedSolid]

My first thought was unironically "hm, sounds like it needs spark plugs" before I saw the 'TDi'. gl with fix.

 

[MopedMan]

Yeah,

After I pressed poses I thought "maybe I should have said it's a diesel first"

 

[RobertJG25]

I'm not sure if its the same for diesels, but when you cold start a gas engine typically the rpms will sit above 1k for a minute or so while it warms up the catalytic converter. So that initial roughness while idling is probably normal? After that it the 'lumpiness' may not be

 

[MopedMan]

I'm not sure if its the same for diesels, but when you cold start a gas engine typically the rpms will sit above 1k for a minute or so while it warms up the catalytic converter. So that initial roughness while idling is probably normal? After that it the 'lumpiness' may not be

In cold weather you'd expect a diesel to struggle to start, as they don't rely on a spark to ignite, rather, a rapid increase in temperature due to an increase in pressure.

The weather here in Ireland has been relatively mild, so lumpy idles shouldn't be happening. If I knew what the values were supposed to be, I could use my VAGCOM to determine if I have a dodgy injector.

 

[MopedMan]

Just an update on this.

I carried out an injector minimum deviation calibration, and it fixed it

Process took 25-40 minutes to complete (I popped off for a cuppa tea before it finished), so it might be worth while for someone in the same boat.

 

[MopedMan]

Another update.

Got about a week out if the min. deviation calibration before the issue came back

Seems to be a bit worse now, white smoke when cold starting and very very lumpy. But once it's at temp, it's all ok.

I've tried to get injector readings in my VCDS, but I can't seem to find them? Did the reading method change in certain model, as any tutorials I find have different options.

There's no pressure building up in the coolant tank, and the coolant level has not dropped, neither has the oil, so I'm still certain it may be an injector issue