Octavia mk2 1.9 tdi bxe engine running very rough sometimes struggles to start cranks for ages before it fires. Then runs really rough as can be seen in the video it sounds terrible i have had the injectors changed like 3 times but no change have checked the injectors on vcds and there within the tolerances. Changed fuel pump no change. Flywheel is fine just at idle it's like this it's ok while driving. I don't know whatelse i can do...? Someone help please. Vcds shows no faults on engine no warning lights nothing. Just runs terrible.

 

Here is another video where you can see it's running worse than the video posted.

 

https://youtu.be/pGSsUqXkksw

Are these not the engines with the known camshaft issues?

Just because the fuel components are not causing an issue, it doesn't mean something else isn't messing up the fueling.

 

I personally would work through it methodically, firstly check the electrical side.. wiring, plugs.. the usual.
Read live data for the main sensors (Temp sensors, Air Flow, Lambda and Position sensors) and make sure they are in tolerance, I have had cars with faulty EGR valves not show any codes or lights.

 

Move on to the basic principles of Intake, Fuel, Exhaust... 

 

Inlet -  Searching for things such as air/vac leaks, any unmetered air can cause rough running and starting issues, smoke tests/pressure testing is the best option.

            Does the inlet have swirl flaps, if so, do they operate? The actuator could may well work, but the ECU won't see if the flaps have failed. 

            Throttle body.. to a basic reset and monitor the live readings.

 

Fuel - 

 

Exhaust -  Any leaks pre-sensor.. blocked cat... EGR stuck/coked up?
 

If the engine is getting the basics of air & fuel and at the right time (sensors/timing), the rough running will be down to something internal so then you need to look at cylinder leakage tests etc.

I haven't done many of the 1.9TDi's so some of the above may not apply, but it is the same basic principle.

 

 

Hi thanks for the reply camshafts are fine mate all sensors everything is plugged in and nothing showing up on vcds... Egr is fairly clean to. 

 

I don't know about swirl flaps with this engine mate.

 

The cat is not blocked either.

Is there A common place to find leaks or broken wires possibly? 

 

Garage guy said cylinders and internal engine looks fine to...?

 

Any more help?

Hi thanks for the reply camshafts are fine mate all sensors everything is plugged in and nothing showing up on vcds... Egr is fairly clean to. 

 

I don't know about swirl flaps with this engine mate.

 

The cat is not blocked either.

Is there A common place to find leaks or broken wires possibly? 

 

Garage guy said cylinders and internal engine looks fine to...?

 

Any more help? Do you know of any vcds i can get from ebay cheap that will do the job??

4 hours ago, JFSR_777 said:

Hi all some more information im getting misfire on control module 1? Injector 1 ?? Some pics

 

Here is a link to the live read out data thanks.

 

https://youtu.be/JPr-l60MBmo

What is the torsion value in VCDS?

 

If it is 0.0° be very wary and rev the engine to see if a small negative value appears, I may have got that backwards and it goes positive at higher revs, in any case you are looking for an actual value and not 0.0°.

 

Was any work done which preceeded this idle roughness?

 

It does sound tappety.

1 hour ago, J.R. said:

What is the torsion value in VCDS?

 

If it is 0.0° be very wary and rev the engine to see if a small negative value appears, I may have got that backwards and it goes positive at higher revs, in any case you are looking for an actual value and not 0.0°.

 

Was any work done which preceeded this idle roughness?

 

It does sound tappety.

Hi thanks for the reply torsion value is -2.9. Which is pretty bad from my understand ing? Should be between 0 and 1 apparently? 

 

Car had a second engine ran fine for months then this happened basically. If you watch the youtube video all the live readings are there if you can give me some further advice? Tomorrow im going to check the injector plugs make sure there all tight and do a continuity test to make sure there are no breaks in the wires. Anything else i should check?

I think that 2.9 is just on the threshold of it not giving a reading and defaulting to the 0.0° figure, it is devilishly hard to even tweak it within the limits that it gives the readings for and takes a lot of patience and nudging to get it close to a true zero, I know when mine was on the limit it had a very rough idle, so rough that I did not even want to try driving it and it was reluctant to fire up so I would advise you to attend to that before any other faultfinding.

2 hours ago, J.R. said:

What is the torsion value in VCDS?

 

If it is 0.0° be very wary and rev the engine to see if a small negative value appears, I may have got that backwards and it goes positive at higher revs, in any case you are looking for an actual value and not 0.0°.

 

Was any work done which preceeded this idle roughness?

 

It does sound tappety.

Hi thanks for the reply torsion value is -2.9. Which is pretty bad from my understand ing? Should be between 0 and 1 apparently? 

 

Car had a second engine ran fine for months then this happened basically. If you watch the youtube video all the live readings are there if you can give me some further advice? Tomorrow im going to check the injector plugs make sure there all tight and do a continuity test to make sure there are no breaks in the wires. Anything else i should check?

Hi ill try get it between 1 and 0 tomorrow if i can however whats your view on the cylinder 1 issue? Do you mind watching the youtube video all the live data is there and see if there is anything else you can pick up on? Thanks

Sorry am in the UK and using my French mobile for internet access, no videos for me!!!

Im in the uk to not sure what the issue is...? Thanks anyway

I live in France & have no phone or ADSL in the UK, I am using my limited data allowance on my French mobile phone to use the computer, videos would gobble it up.

Just an update i tightened the injector loom connectors and put it all back together egr was fairly clean. Started the car and it still ran rough for about 15 minutes than seemed to have cleared up and running sweet again. However when i rev the car now im getting alot of smoke but the engine is running correct no vibrations or rough start any idea anyone? Injector readings also seem to look ok now?

Ok once the engine has cooled down its back to running rough again....? Any ideas anyone im confused on what to do now?

Is it worth changing the injector loom, it's a known fail as it has a hard life re heat and is sat in oil - and it's a cheap job. Especially when messing with the connector made a difference. 

Edited 16 October, 20214 yr by bigjohn

I had a similar problem, injector 1 electrical plug was bad.

 

Nipped up the female spade connectors in the plug for a tighter fit on the injector, problem solved.

Unfortunately it did not fix my problem mate.