Bahhhh Only had the car a few days and it begins! Car has a full complete service history right up to 1500 miles ago ish and today I hear an alarm outside so I go look and it's mine, I go to get key and it stops so I leave it. 40 min later I need to go out somewhere and thought as I had windows open in the head but only pressed lock once that it had gone off from a fly or something getting inside. I get in key on lights all come on and off as per normal and car starts and runs for about 2 seconds then cuts out. I try to restart and it turns over nice and fast but doesn't start, it sounds like it really wants to but then just doesn't. 
 

Battery is showing 12.4v on multi meter and I only put it in the car from my other Octavia (Varta E44) the other day as the smaller weaker battery that came in the car was only showing 12.2V.

 

Tried locking car and unlocking and no difference, only have VCDS with a KKL cable which doesn't let me check anything other than the engine module which comes up with no codes.

 

No VCDS locally that I can find to use in short term...

 

Any ideas? Crank sensor, battery, immobiliser etc all runnign through my mind.

 

Oh did 250 ish miles yesterday no issues and 60 or 70 the day before and all was perfectly well, last service included fuel filter sub 1500 miles ago. 

Left battery disconnected for 30 min no joy. Tried using other car to supplement it's power and it started on jump cables. 

 

Battery showing 12.4V when car off 14.4V when car is running? Is that within tolerance you'd expect for it to work or not? Weird thing with battery is that old one was showing 12.2V with the car off and 14.3V with the car on but seemed to run fine, I only changed as the other battery was more suited to it. Now can't risk driving the car just in case it leaves me stuck!  

Where about are you - I've vcds in north down, but there's quite a few about? Sounds like the battery - fully charged and idle with no load should be at least 12.4V rather than a minimum 14.4V is only the charging voltage, battery voltage under starting load will fall dramatically - often not reaching minimum crank speed for the tdi ecu to enable the injectors to supply fuel.

3 minutes ago, Stevie D said:

Where about are you - I've vcds in north down, but there's quite a few about? Sounds like the battery - fully charged and idle with no load should be at least 12.4V rather than a minimum 14.4V is only the charging voltage, battery voltage under starting load will fall dramatically - often not reaching minimum crank speed for the tdi ecu to enable the injectors to supply fuel.

 

Im down by Enniskillen :( Was up in Belfast yesterday annoyingly with no dramas in it. 

 

Biggest issue is no one to turn key to check load on multi-meter to see if it dips too low and I've a dead cell or something. The battery is hopefully all it is, but I want to get a in depth scan first. The sound of it was like fuel starvation so would make sense, but if some random immobiliser fault, it could get messy. Randomly when indicating the battery light very dimly flashes with the indicators on the dash and comes on very dimly when doors are opened and internal lights come one. I wasn't initially concerned about this as I've seen lots of Mk2 Octy's do this and other weird things with faintly lit dash lights, inc my new Mk2 FL one at about 2 years old, which annoyed me as it was a new car, but Skoda were useless so I sold car on in a temper. 

Car has been fine since, no idea what it was. Battery checks out to be tip top on dealers tester when I had air con service done on it today. Full scan no codes bad the low AC one which is now cleared and gone. Car has started and run fine after days of inactivity too each time. Seems very odd indeed. Initial thing was it started ran for 2 seconds then cut off which is in line with immobiliser cutting it off, but upon trying to restart it just turned over but didn't fire. I'd expect if it was immobiliser it would do the same each time and run for 2 seconds then cut, immobiliser light comes on and off as it should each time. 

 

Loosely I can only think of two things in lieu of any codes or associated lights on dash etc. Air in fuel system, the fuel filter was changed not overly long ago and the lid of the filter housing is a factory one still, but with new bolts in it, but then how did it suddenly clear and work fine ever since? Perhaps a drain of battery in the 24 hours it was parked up after using it last before, I did have temp dash cam installation in with cable hanging down for 12V socket, not plugged in but cable pushed into the glove boxes door gap to stop it waving around when driving, this may have caused the light in there to remain on, but I'd not expect 24 hours of that to kill it, maybe it was just enough to be too low to want to start though. Then the alarm randomly going off, never did it before and hasn't done it since. 

The only other code I got off it which I cleared and hasn't come back was for 'interior button drivers door' and no alarm or immobiliser activation codes coming up. Maybe the car after alarm had gone off and I unlocked and opened drivers door, it didn't detect I had opened the door and thus didn't allow start with key? Then the key itself / dash pod... Key is only one I have, need to get a new spare fast, the battery works in it, but doesn't have a massive range on it, this shouldn't affect the transponder if it's just a dead chip for dash pod to read? 

 

I got my warranty stuff through the post yesterday and it's for 6 months not the 3 months I was told, might help soften the blow if something pricey does need replaced a little. 

 

I did see some posts in my endless searching on here for folk with same engine experiencing cold start issues with turning over time being extended and taking a lot longer than the max of 5 odd seconds at a time I let it try for after it cut out (normally starts instantly). The car is a 57 plate bang on Sept 2007 so don't think it would require new battery to be coded to ECU. 

 

 

The old battery removed vs the Varta E44 I replaced it with: 

Edited 6 May, 20179 yr by FUBAR