only running on 3 cylinders?

1. rockrocks L-plater Joined: Apr 2011 Posts: 78

   #1 13th December 2011, 16:57

   ok, so i know this isnt about a saxo but there are a lot of people on here with some really good advice so im wondering if you could help me.
   
   me friend has a vw polo 1.0 and he says its only running on 3 cylinders, he's changed the spark plugs, HT leads and ignition coil.
   
   any ideas what the problem might be and how he can fix it?
   
   thanks guys
2. user_36198 Saxperience Post Whore Joined: Aug 2009 ilkeston derbyshire Posts: 9823 C2 VTR stripped, 406hdi, clio 172

   #2 13th December 2011, 17:02

   compression test next my friend, assume its the single point injection engine? try and isolate which cylinder has a fault by disconnecting one ht lead at a time, one will make no difference to the running of the engine and that will be your duff cylinder. if its a multi point engine, it could also be an injector.
3. willis54 Regular Poster Joined: Dec 2011 Swadlincote Posts: 260 MK1 1.4i Westie Mango

   #3 21st December 2011, 14:22

   i would also check the injectors, as if a injector is failing the cylinder would misfire. also check the map/maf sensors as if there not working this would also lead to a misfire