1.4 Petrol: No signal to injectors

[Avantone]

Hi,
Been loving our new (to us) A2 1.4 petrol, but yesterday the EML came on and it was clearly only running on 2/3 cylinders. My cheapo scanner reported various misfires on codes P0300, P0302 & P0303.
The next morning it turned over but wouldn't start. I called the AA and they said the ignition was fine, but diagnosed that power to the injectors was fine, but no there was no pulse/signal for them to actually fire - he suspected an issue with the ECU, particularly as it appeared to shut down every time he tried to reset a particular code (P1582 - Throttle valve (TV) control unit).
This was as far as they could take it and recommended booking it into a dealer/specialist and offer relay.

So, the cars booked in, but in the mean time, I'm asking if this is familiar to anyone, and what do you think the issue/fix could be?

Many thanks, Tony

 

[Robin_Cox]

Coil? Granted, the ignition comment probably excludes this.

On our AUA (one coil pack for all four cylinders) this was ultimately the cause of a year of intermittently rough running particularly in damp weather, which culminated in running on 3 cylinders, misfire counters going nuts and then stalling. Had already replaced spark plugs and leads (and EGR, and throttle body as they were filthy / failed!). A new cheap coil off Amazon was already better but one circuit failed on arrival, so I then bit the bullet and bought the full price Bosch one - and this did the trick. Ironically, removing the old one revealed cracks in the casing and insulation all around the back and underside that weren't visible when bolted in place.

Otherwise crank position sensor? Best of luck!

 

[Avantone]

Coil? Granted, the ignition comment probably excludes this.

On our AUA (one coil pack for all four cylinders) this was ultimately the cause of a year of intermittently rough running particularly in damp weather, which culminated in running on 3 cylinders, misfire counters going nuts and then stalling. Had already replaced spark plugs and leads (and EGR, and throttle body as they were filthy / failed!). A new cheap coil off Amazon was already better but one circuit failed on arrival, so I then bit the bullet and bought the full price Bosch one - and this did the trick. Ironically, removing the old one revealed cracks in the casing and insulation all around the back and underside that weren't visible when bolted in place.

Otherwise crank position sensor? Best of luck!

Thanks Robin,
I did the same and ordered a cheap coil on Prime. I didn’t fit it before the AA guy came because I didn’t want them to think I was “hoping and poking” and he could start from fresh. I didn’t bother afterwards given his diagnosis on the injector signal.
Think the crank sensor is a logical call rather than the ECU, but I haven’t got experience on these so better start searching!


Sent from my iPhone using Tapatalk

 

[damadgeruk]

Welcome to the forum. I'd suggest the best plan is to arrange a VCDS scan as generic scan codes can be misleading.
Thread here...

VCDS (or Other) Free Scan Register - Volunteers Needed

This is an invitation to members to be added to a soon to be published VCDS register of members who offer free VCDS (or other) scans to members. The register will be a concise list arranged by volunteer location and username and kept up to date. The following is a list of members who have...

www.a2oc.net

 

[PlasticMac]

Thanks Robin,
I did the same and ordered a cheap coil on Prime. I didn’t fit it before the AA guy came because I didn’t want them to think I was “hoping and poking” and he could start from fresh. I didn’t bother afterwards given his diagnosis on the injector signal.
Think the crank sensor is a logical call rather than the ECU, but I haven’t got experience on these so better start searching!


Sent from my iPhone using Tapatalk

When you crank it, does the rev counter indicate this (few hundred revs) , or maybe it does not move? If no movement, suspect crank sensor.
Mac.

 

[Avantone]

When you crank it, does the rev counter indicate this (few hundred revs) , or maybe it does not move? If no movement, suspect crank sensor.
Mac.

The battery's on it's last legs now, but I've just tried it. Though it wasn't cranking very fast, the rev counter needle was stationary.

 

[Robin_Cox]

Sounds plausible. I should note that my crank sensor comment above was a repetition of something I'd heard here in a different thread. Needle readout though although sounding useful on that thought makes me think of something else - maybe having an ODB reader hooked up could give you a bit more low-down sensitivity (in the same way that temperature gauges are flatlining at 60' when direct sensor reads are giving numbers around or above room temperature below the 60'C minimum needle reading) so you could see a rev twitch on the reader where the needle doesn't budge at all? Thereby giving you an idea if the crank sensor is turning over and giving sensible numbers to the output (or not, as the case may be).

 

[Andrew]

Welcome to the forum. I'd suggest the best plan is to arrange a VCDS scan as generic scan codes can be misleading.
Thread here...

VCDS (or Other) Free Scan Register - Volunteers Needed

This is an invitation to members to be added to a soon to be published VCDS register of members who offer free VCDS (or other) scans to members. The register will be a concise list arranged by volunteer location and username and kept up to date. The following is a list of members who have...

www.a2oc.net

Hi,

The thread you linked was really the initial recruitment thread for the scan register. Now the register is up and running best to link in future the register itself here

Free Scan Register

This is a register of members who generously offer free scans for other members. To arrange a free scan: 1. Click the pdf map in the footer and choose a location. 2. Cross reference the location number in the table below to identify the member. 3. Click on their username on the left, click...

www.a2oc.net

Good you thought of it.

Andy