Tdi running rough

[rosscanning]

Hi everyone, been a while since i have posted something on here.

So I have a little project TDI which needs a little attention.
First job i need to look at is it’s running on two cylinders most of the time but the odd time it’s runs sweet as nut back on three cylinders.
I managed to do a scan some weeks back and injector 1 is flagging up, unfortunately I don’t have the exact description as i lost my phone (which had the code saved ) and vcds has gone awol on me.

So from past experience it’s looking like injector harness needs replacing. Would you all agree?
But Ultimately i need to get my vcds back up and running to get exact code.

Am I right in saying if the actual injector is at fault it would run rubbish all of the time? Which is swaying my decision its the wiring harness at fault…?

Any help much appreciated
Thanks
Ross

 

[audifan]

Could be a dirty or blocked injector. What condition is the fuel filter in?

Injector looms have a hard time and although you can tighten the connectors onto the injectors remember the wiring has been living in hot / cold oil for many years. You could measure the resistances for each of the injectors by probing the rear of the big nut.

So I would probe the big nut and run some Clean Drive or Cataclean through the fuel system according to the manufacturers instructions followed by a new fuel filter.

 

[Howey]

All valid points by @audifan

My black one did this I removed the loom and tightened all the connectors and refitted, it's a bit of a faff and I even super glued the ruddy plastic back together but it's been fine since. You can also check injector readings in vcds for a before and after.
My black car is more lively than the silver one so I might look at Mr Silvers loom when I get more pressing issues out of the way.

 

[kp 115]

Hi everyone, been a while since i have posted something on here.

So I have a little project TDI which needs a little attention.
First job i need to look at is it’s running on two cylinders most of the time but the odd time it’s runs sweet as nut back on three cylinders.
I managed to do a scan some weeks back and injector 1 is flagging up, unfortunately I don’t have the exact description as i lost my phone (which had the code saved ) and vcds has gone awol on me.

So from past experience it’s looking like injector harness needs replacing. Would you all agree?
But Ultimately i need to get my vcds back up and running to get exact code.

Am I right in saying if the actual injector is at fault it would run rubbish all of the time? Which is swaying my decision its the wiring harness at fault…?

Any help much appreciated
Thanks
Ross

Darkside developments had the looms if you want to go down the replacement route.
Cheers
Keith.

 

[rosscanning]

Could be a dirty or blocked injector. What condition is the fuel filter in?

Injector looms have a hard time and although you can tighten the connectors onto the injectors remember the wiring has been living in hot / cold oil for many years. You could measure the resistances for each of the injectors by probing the rear of the big nut.

So I would probe the big nut and run some Clean Drive or Cataclean through the fuel system according to the manufacturers instructions followed by a new fuel filter.

Thanks for reply, very helpful.
I’ve got a new fuel filter ready to fit but haven’t changed one yet any advice for changing metal type filter?

All valid points by @audifan

My black one did this I removed the loom and tightened all the connectors and refitted, it's a bit of a faff and I even super glued the ruddy plastic back together but it's been fine since. You can also check injector readings in vcds for a before and after.
My black car is more lively than the silver one so I might look at Mr Silvers loom when I get more pressing issues out of the way.

Yes its a fiddly job to do.

Once i get my vcds up and running again i will have to see how i can see readings from injectors.

Darkside developments had the looms if you want to go down the replacement route.
Cheers
Keith.

thanks ill keep them in mind if i need to go down that route of a new loom

 

[audifan]

Clamp off the fuel lines to prevent draining the tank and introducing more air into the lines. Clean off any dirt in the area of the pipe ends. Carefully remove one line at a time and fit onto the new filter in the correct position making sure you do not damage the connections

Be very careful when removing the valve from the top of the old filter as getting correct replacement ones is very difficult. Replace the seals on the valve before fitting into the new filter.

Remove the clamps from the lines and with a fully charged good battery crank for 6 seconds and then turn off. After 30 seconds crank for 7 seconds and turn off. After another 30 seconds crank for 10 seconds. If the car starts during this process let it run for a couple of minutes and check the connections on the filter for leaks.

As this is an old diesel ( metal filter ) I suspect the tandem pump is already worn and need replacing.

 

[CrispyEdd]

Was it 0.5 ohm resistenace for the injector loom?

 

[audifan]

Sorry Edd can not remember the resistance value now. What is more important is they are all the same and low. Make sure you are checking the correct wires for each injector.

 

[rosscanning]

Thank you everyone helpful as always.

I sold my A2 last year and like most of us we end up buying one not long after haha
I’ll change the filter see if that does anything, as for fuel additives I usually use liqui moly but never heard of Clean drive before….

Thanks again
Ross

 

[audifan]

CLEANDRIVE® – ADVANCED FUEL & EXHAUST SYSTEM CLEANER – Eco-Motive

CleanDrive® is scientifically proven to enhance the fuel efficiency and overall performance of any vehicle by improving the combustion process and fuel efficiency of the engine. Improves fuel efficiency (MPG) up to 15% Use before an MOT to improve emission test results Brings the...

eco-motive.com

 

[dj_efk]

I would go diesel purge on this one to rule out blocked / dirty injectors Ross. Search for "diesel purge 101" - Paul's experience (among others) is invaluable

 

[rosscanning]

CLEANDRIVE® – ADVANCED FUEL & EXHAUST SYSTEM CLEANER – Eco-Motive

CleanDrive® is scientifically proven to enhance the fuel efficiency and overall performance of any vehicle by improving the combustion process and fuel efficiency of the engine. Improves fuel efficiency (MPG) up to 15% Use before an MOT to improve emission test results Brings the...

eco-motive.com

Thank you

I would go diesel purge on this one to rule out blocked / dirty injectors Ross. Search for "diesel purge 101" - Paul's experience (among others) is invaluable

thank you also will have a look

 

[rosscanning]

So a little update.

Brimmed the new fuel filter with some liqui moly (i had some already). There’s a slight improvement on running.

This is what came out of the old filter (looks like oil rather than diesel)

(white fluid is left over fabric conditioner)

Managed to fix my vcds so now i have some live readings from injectors can someone to help if they are correct or not please?

Cylinder 1 P1666 electrical malfunction

Injector readings:
Cylinder 1 2.99 mg/str
Cylinder 2 -2.07 mg/str
Cylinder 3 -1.25

This was from after i changed filter, what’s everyone thoughts? Injectors them selves or with harness because of the fault code P1666 Electrical malfunction cylinder 1.

And a couple of other fault codes I’m not familiar with…

G45 front right wheel speed sensor.

Temperature evaporator G263

Any help will be hugely appreciated

Thank you

Ross

 

[audifan]

Cylinder 1 injector has an issue. Either the injector loom is not making contact or the injector itself is faulty.

The front right ABS sensor is either faulty, has poor connection or the loom is damaged although could also indicate a wheel bearing issue with the inductor ring.

Your battery has gone low on charge and triggered some faults. Fully recharge the battery or replace it if old clear the faults and rescan for current ones.

Worry about the climate faults another time.....

 

[rosscanning]

Cylinder 1 injector has an issue. Either the injector loom is not making contact or the injector itself is faulty.

The front right ABS sensor is either faulty, has poor connection or the loom is damaged although could also indicate a wheel bearing issue with the inductor ring.

Your battery has gone low on charge and triggered some faults. Fully recharge the battery or replace it if old clear the faults and rescan for current ones.

Worry about the climate faults another time.....

Thanks for reply!

yeah my main priority is the injector and abs sensor.

Now with the sensor at fault i get the obvious lights on dash but weirdly when i rev past 2500rpm’s the red exclamation appears, Never came across that before.

Anyways ill looking into a new loom next.

Thanks again

Ross

 

[audifan]

Thing to remember is several systems share sensor information, such as ABS, traction control , stability control and even the speedometer. So if there is a faulty sensor then other systems will also report a fault. Check the loom for tyre damage and also the condition of the plug as it fits onto the sensor. New sensor not expensive. If it is the bearing then that gets a lot more complicated and expensive.

Have you checked the injector loom resistance for each injector ( especially cylinder 1 ) at the big knurled nut next to the tandem pump? The loom can either be tightened onto each of the injector terminals or replaced for new. Replacing the injector is more involved.

Again full charge the battery or replace it and rescan.

 

[PlasticMac]

Thanks for reply!

yeah my main priority is the injector and abs sensor.

Now with the sensor at fault i get the obvious lights on dash but weirdly when i rev past 2500rpm’s the red exclamation appears, Never came across that before.

Anyways ill looking into a new loom next.

Thanks again

Ross

It may dissappear, because the alternator manages to get the voltage up to more than 12.5 V. As Graham says, sort the battery situation out, before relying on fault codes.
Low battery voltage generates more faults than an FSI on 95 octane!
Mac.