Help please - Golf TDI 'miss-firing'
Discussion
its a W-reg 1.9 tdi (pre-PD) engine with 200,000 miles, and it has started miss-firing really badly. Here's the symptoms, any ideas?
Does it hot or cold.
Has not been recently refuelled. Has 1/4 tank of 2-week old fuel in it.
Tickover is fine, and it starts instantly.
On light throttle it sounds like it's dropping to 3 cylinders, and then it is smoky.
Its better on full throttle, but drops dead (cuts out) at c.3000rpm
It is not smoky when its not missfiring
Glow plug light is flashing after a lot of missfiring
Glow plug light will not come on if driven full-throttle/no-throttle only (tricky!!)
ABS light has come on as well. ABS is not functioning.
Turbo is sounding normal
Exhaust has a leak just after the cat
No bubbles visible in the clear fuel pipe
Disconnecting vacuum from EGR has no effect.
Bizarrely it seems fine in reverse.
No fault codes showing on OBDII codereader.
Any ideas?
Does it hot or cold.
Has not been recently refuelled. Has 1/4 tank of 2-week old fuel in it.
Tickover is fine, and it starts instantly.
On light throttle it sounds like it's dropping to 3 cylinders, and then it is smoky.
Its better on full throttle, but drops dead (cuts out) at c.3000rpm
It is not smoky when its not missfiring
Glow plug light is flashing after a lot of missfiring
Glow plug light will not come on if driven full-throttle/no-throttle only (tricky!!)
ABS light has come on as well. ABS is not functioning.
Turbo is sounding normal
Exhaust has a leak just after the cat
No bubbles visible in the clear fuel pipe
Disconnecting vacuum from EGR has no effect.
Bizarrely it seems fine in reverse.
No fault codes showing on OBDII codereader.
Any ideas?
With a diesel it has to be fuel as it's compression ignition. Check for a split fuel line sucking in air, can be hard to spot. If it isn't this, then it's likely to be injector related, either the injector itself or something electrical preventing it from working properly.
I've encountered both of these, the first on a Pug 106 diesel and the latter a wiring loom fault on a Td5 Disco.
I've encountered both of these, the first on a Pug 106 diesel and the latter a wiring loom fault on a Td5 Disco.
could be the injector loom breaking down.
One side isnt supported very well and after 200k of vibrating diesel action its prone to failure.
Happened to ours and the part was about 40 quid. Get someone to VAGCOM the car to show the fault, or get yourself a cheap ebay code reader which is what I did to diagnose ours.
One side isnt supported very well and after 200k of vibrating diesel action its prone to failure.
Happened to ours and the part was about 40 quid. Get someone to VAGCOM the car to show the fault, or get yourself a cheap ebay code reader which is what I did to diagnose ours.
Update -
The weather's been too nasty to go outside and fiddle with the car, so I nipped to a friendly garage and got the codes read properly.
Its showing as an intermittent electrical failure at the diesel pump. Which is quite bad news as that'll be expensive. The good news is that disconnecting and reconnecting the plug has fixed it, so it seems like just a dicky connection, fingers crossed.
The weather's been too nasty to go outside and fiddle with the car, so I nipped to a friendly garage and got the codes read properly.
Its showing as an intermittent electrical failure at the diesel pump. Which is quite bad news as that'll be expensive. The good news is that disconnecting and reconnecting the plug has fixed it, so it seems like just a dicky connection, fingers crossed.
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