Hi All, My Octavia Scout 2ltr TDi has had a lumpy tickover for ages and I am now trying to fix it, I have done a scan and its not shown any faults so I assuming that a sensor is within its 'normal' range of value, but its reading say at the top or bottom of its range ! It seams to run better when its this very hot weather so are there any sensors that are common for being faulty ? I have VCDS so which channels (sensors) should I monitor or record with the VC scope ? Cheers Stuart

I had a Lumpy tick-over on my 2.0 tdi. It was a leaky injector. My mate looked at injector quantities of requested vs actual. It showed one way out of range (3.99) when it should have been about 0.75 (figures not accurate just as examples). It also showed the other injector quantities trying to adjust. Replaced injector and idle now smooth. Not sure of addresses he looked at in VCDS buts it's there. 

Hi Nick, thanks for that, I will have a look at the injector quantities etc, at least it gives me somewhere to start. Cheers Stuart

I had this in my previous 2.0 PD unit, could NEVER find the issue. Had it in to several garages and a lot of sensors replaced but it would still do it.

 

Was worse when the ambient temperature was colder, was fairly smooth when engine was up to temp...injectors were a bit over the place but well within spec. You could see in the VCDS measuring blocks for injectors that they were balancing themselves out too.

 

I had blue smoke from cold startup too, so likely leaky injectors, but at several hundred per injector it was cheaper to live with it in case it didn't fix it.

 

Anyhoo, it was group 13 under engine measuring blocks if you want to check the injection values.

 

 

I also managed to smooth it out further by fiddling with the idle speed, again via VCDS. Winter time I would jack it up to around 900 rpm and in the summer, back to around 840 rpm.

 

I got a 2nd hand injector for £40. Got it tested by a mate with the proper kit. It was 90% efficient so as new. Bought seal kit from Darkside for about £10. Got it fitted for about £100. Running sweet. 

Thanks for all the replys, I must admit I have lived with it for a year and thought a sensor is on its way out and it will Eventially go ! But the problem remains, there's no blue smoke so I suppose the injectors are OK as per leaking, so I will just have to keep monitoring sensors and see if one is at the end of its 'normal' range but not for the engine temperature or load. Cheers Stuart 

My 2.0 PD is the same, no blue smoke on start up but when its half way between cold and hot it starts with the very lumpy tick over, Switch an electrical source on ( eg heated rear window ) it ticks over great. Sorts itself out when hot..Have not found the cause yet???   seems a very common problem...

Mine had smoke at start-up so deffo leaking overnight. Ran fine at speed but on hot days like last June with aircon on I was driving through Oxford and stuck in traffic and it got very very lumpy indeed. SO much so it spurred me on to get it sorted.

On 6/9/2018 at 12:47, Doofy said:

My 2.0 PD is the same, no blue smoke on start up but when its half way between cold and hot it starts with the very lumpy tick over, Switch an electrical source on ( eg heated rear window ) it ticks over great. Sorts itself out when hot..Have not found the cause yet???   seems a very common problem...

 

Ah yes, true, for me switching on the AC and rear heated windscreen also helped smooth the idle out. Almost needed a bit of extra load on the engine to smooth it out it appeared. 

 

I lived with that for 10 years lol.

Thankfully other bits of the car out weighed that annoyance. No garage I took it to could fine the fault though. I tried Skoda dealers, good local garages and even a VAG specialist.

 

 

 

Same here, had the car to different garages and no one can identify the problem, Just get told it's ''probably'' the injectors...

Hi All, I tried putting a load on the alternator HRW,lights etc and it makes no difference, I put vcds on it today and it shows the fuel temp as 73.8c when the outside temp is 30c so I am going to change it if I can find it, going off the internet its like a letter T that goes in the fuel line somewhere ? it also shows EGR (actual) is 430mg/str when ross-tech say it should be 300 max although EGR (spec) is 285mg/str so that could be another fault, also air intake G72 was reading 51.3c when it was 30c !  cheers Stuart