Hiya guys, I'm new to this forum  I've bought a 2006 Fabia Ambiente 1.2 12v around two weeks ago, and everything was fine when I checked it before buying it with my dad and brother. A day after buying the car the engine light came on, I've had it checked at the garage and can't exactly remember all errors but definitely there is a cylinder 3 misfire after the car warms up and runs on idle for a couple of minutes e.g. waiting at the lights. One other error was also something about the map sensor (sorry about the lack of detail but I'm not much of a car person, this is my first car and I'm learning as much as I can, and also a friend at the garage was checking it for me so I didn't write it down), so I'm suspecting it might be the map sensor - will get it out and clean it with my brother who is a car mechanic. So far I've changed the plugs and ignition coils, still no luck. Any ideas as to what it might be?

could be a leaky injector if its when your waiting at the lights etc other than that check compression with your mechanic brother? a map sensor reads the air pressure etc and fuels all the cylinders the same so can't see it making just one cylinder missfire 

Edited 25 September, 20178 yr by thomasaspin

I would ignore the map fault for now it's not unheard of to get a map fault with a missfire. 

 

My money would be on a problem with the valve seat, a compression test may reveal something, but with out more Info it's a stab in the dark. 

2 minutes ago, thomasaspin said:

could be a leaky injector if its when your waiting at the lights etc other than that check compression with your mechanic brother? a map sensor reads the air pressure etc and fuels all the cylinders the same so can't see it making just one cylinder missfire 

I completely forgot to mention, we've done the compression and everything is in order.

Just now, Narusuji said:

I completely forgot to mention, we've done the compression and everything is in order.

you've elimated the main culprates being spark source (coil pack) and spark plug , try swapping the cylinder two and three coil packs and wiring plugs and see if the problem moves to cylinder two if it does it may be the wiring on the coil pack plug skodas have poor wiring looms , then last and worst case is a new injector 

watch this it may help you diagnose your problem 

 

Update: Swapped the plugs on coil packs (cylinder 2 and 3), and once I start up the car it's behaving very weird - vibrates much more than when the plugs are where they should normally be, and also the revs go all the way down to 500. Engine sounds like it's gasping for air and pressing the throttle does absolutely nothing. Called my brother and he said it's either the cables/plugs or the regulator(distributor?). Going to wait until he finishes work and he's gonna have a look at it.

@Narusuji - That engine doesn't have a distributor.

Swapping the plugs onto the 'wrong' coilpacks will screw up the ignition timing, so not surprised that hasn't resulted in a lot of success.