x1x_el Posted December 19, 2022 Report Share Posted December 19, 2022 Hi dudes, I’ve got a 1L Arosa S, and she’s my first car. Due to illness I was unable to drive her for a week. I just started the car, and it was humming, shaking and the EML was flashing. After 3? minutes I took the keys out and tried again. This time less shake and no EML, but still not running how it used to. I took the car on a drive, and accelerating and changing gears she shudders. As if there’s a resistance to driving. Even going from 20-30 mph she shudders - like she’s trying to refuse accelerating. Quote Link to comment Share on other sites More sharing options...
mk2 Posted December 20, 2022 Report Share Posted December 20, 2022 Lupos are not smart enough to have a limp mode... any change means a fault. From the symptoms, it sounds like it might be ignition related. Check the high voltage ignition leads. Feed to coil and any for condensation anywhere. Worth a try with a water displacer like "water displacer blend 40"... Almost certainly weather related, with crazy cold followed by sudden wet warm up. 1 Quote Link to comment Share on other sites More sharing options...
pond Posted December 21, 2022 Report Share Posted December 21, 2022 Hope you don't mind me "piggy-backing" on your thread x1x, but I have virtually identical symptoms same car and I really hope some people can help with the most common causes. I have tried your suggestions before finding this thread mk2 and am open-minded to anything but thinking lambda sensor related maybe. It might be better to start a fresh thread. It probably is a coincidence, but mine has happened out of the blue on a 40k mileage car that has run faultlessly until now, and this was after sitting at -8 degrees for several nights. Quote Link to comment Share on other sites More sharing options...
mk2 Posted December 21, 2022 Report Share Posted December 21, 2022 Yeah, I fixed a mk4 with the same symptoms. Was Ignition leads full of condensation. And coil pack condensation. Open the bonnet in the dark and see if you can see the HT arcing. Can't remember what access you have on that engine, but while rough idling pull a plug lead off; if it makes no difference, then that's the one with the short to earth. Lambda sensors don't fail. Otherwise could be temp sensor or dodgy crank sensor? Quote Link to comment Share on other sites More sharing options...
pond Posted December 22, 2022 Report Share Posted December 22, 2022 12 hours ago, mk2 said: Yeah, I fixed a mk4 with the same symptoms. Was Ignition leads full of condensation. And coil pack condensation. Open the bonnet in the dark and see if you can see the HT arcing. Can't remember what access you have on that engine, but while rough idling pull a plug lead off; if it makes no difference, then that's the one with the short to earth. Lambda sensors don't fail. Otherwise could be temp sensor or dodgy crank sensor? as said, it's not spark plug leads, and.. Lambda sensors don't fail? not sure where you got that from - it is last on my list as don't have access to diagnostics anymore but I assure you that they do. 🙂 Meanwhile, was hoping I could get more replies from owners who've experienced similar and then cured other than spark plug leads arcing. Quote Link to comment Share on other sites More sharing options...
mk2 Posted December 22, 2022 Report Share Posted December 22, 2022 Nope, never seen a Lambda/O2 sensor fail. Ever. They get physically broken and the cables, plugs and loom snaps, but the cell itself is very tough... There's not a lot to break in a nernst cell. Anyway, if it's misfiring or running rough, shaking, chances are there's a misfire. So either incorrect sparking or incorrect fuelling (mix). For sparking- Timing originates at the crank sensor, which triggers the spark. The ECU uses the crank data and then looks at air pressure, demand (TPS or MAP or combination), RPM and temperatures and decides the right point in time to chuck out a spark. So if the spark is working, then it's at the wrong time. If no spark, then either the crank pulse is missing or an output device (coil/lead/plug) has failed. For fuelling- the ecu looks at demand and temperatures and at the right point in the cycle opens the injector for the right amount of time to deliver fuel. Assuming the physical injector and fuel pressure hasn't changed, the fuel-air ratio should be fine. If the mix isn't right, then either too much air or not enough fuel. Which means an inlet air leak or wrong fuel pressure (or combination). Or the info the ECU is getting is wrong. So if everything is physically ok- engine not cracked or broken, it has to be a sensor or an output device (like fuel pump/relay/pressure regulator/coil/plug etc). Try temp sensor next...? Let us know how you get on Quote Link to comment Share on other sites More sharing options...
pond Posted December 22, 2022 Report Share Posted December 22, 2022 (edited) Thank you mk2, will start to work my way through everything and will let the Forum know what I find. 🙂👍 @x1x_el how have you got on? Edited December 22, 2022 by pond Quote Link to comment Share on other sites More sharing options...
x1x_el Posted February 12, 2023 Author Report Share Posted February 12, 2023 Apologies this has been quite a while! I did absolutely nothing to the car I cannot lie. I let it sit and run for a bit. Turned off to cool. Back on to sit and run, took on a drive and shes been smooth ever since! I think the december cool and leaving her sit for a week solidified all the oil and fuel. But after heating it back up and re-circulating it I've had no other warning lights and no juddering. The next MOT will also have a service though. Just to get the spark plugs and coil pack changed as I can't imagine they've had a lot of love in the winter chill. Quote Link to comment Share on other sites More sharing options...
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