Engine running rich

1. JonGrose Newbie Joined: Sep 2014 Posts: 21 Citroen Saxo 1.1 (2000)

   #1 4th June 2016, 12:41

   Hi,
   
   I connected a fault code read to my 1.1L saxo and it was saying that it's running 'rich'.
   
   Any ideas how to solve this? A friend of mine suggested replacing the Idle Control Value and the Lambda sensor?
   
   Thanks.
2. bender L-plater Joined: Sep 2015 Weston Super Mare Posts: 49 1998 MK1 Saxo 1.6 VTR 1995 Golf GTI 2.0

   #2 4th June 2016, 12:45

   I wouldn't say the idle control valve would make much difference as it does what it says on the tin, doesn't make much of a difference to the mixture. Lambda is a possibility, or maybe the coolant sensor or MAF sensor.
   What year is your saxo? And is it SPI or MPI?
3. user_20080 Saxperience Hardcore! Joined: Dec 2007 smurfland. Posts: 17346 Ex saxo owner.

   #3 4th June 2016, 20:40

   Faulty coil pack can cause rich running,what are the fault codes?
4. JonGrose Newbie Joined: Sep 2014 Posts: 21 Citroen Saxo 1.1 (2000)

   #4 6th June 2016, 00:03

   Thanks for the replies.
   
   My car is a 'X' reg so about 16 years old now. And I don;t know what SPI or MPI stand for.
   
   Fault code was "P0172".
5. sri_130 Frequent Poster Joined: Apr 2012 Doyncaster Posts: 783

   #5 6th June 2016, 06:09

   Single or multi point injection.
   Coolant temp sensor at a guess.
   
   Sent from my Nexus 5X using Tapatalk
6. BUMMERS Regular Poster Joined: Feb 2016 manchester Posts: 256

   #6 6th June 2016, 09:52

   CTS can definitely cause issues if that goes wrong.
7. sri_130 Frequent Poster Joined: Apr 2012 Doyncaster Posts: 783

   #7 6th June 2016, 13:03

   I'm sure chip wizards or gmc will be on to explain, but the warm up enrichment will prob be based on the CTS. If it provides low readings the mixture will be richened to assist with cold start....constantly.
   Easy enough to rule out though and accessible as well.
   
   Sent from my Nexus 5X using Tapatalk
8. Chipwizards Frequent Poster Joined: Nov 2009 Posts: 576

   #8 6th June 2016, 14:11

   Lambda control isn't active till a certain engine temp, so if your ECU thinks the engine is cold it will always run rich. Check live readings with a scanner and see what is doing what and see that each reading is plausible.
   
   Is it all stock or have you changed something?
9. sri_130 Frequent Poster Joined: Apr 2012 Doyncaster Posts: 783

   #9 6th June 2016, 18:49

   Quote:

   Originally Posted by Chipwizards Lambda control isn't active till a certain engine temp, so if your ECU thinks the engine is cold it will always run rich. Check live readings with a scanner and see what is doing what and see that each reading is plausible. Is it all stock or have you changed something?

   Don't suppose you know what temp the closed loop kicks in? Mine runs a bit hit and miss, like on 3 cylinders unless you feather the throttle, from cold.
   
   Sent from my Nexus 5X using Tapatalk
10. Chipwizards Frequent Poster Joined: Nov 2009 Posts: 576

    #10 6th June 2016, 23:15

    If it runs on three cylinders sometimes there's definitely a problem with it beyond temps and lambdas. A bad injector would be my first area of investigation, especially given the fault code you're getting.