16v map sensor / tick over

1. user_29491 Saxperience Forum Bum Joined: Dec 2008 Lancs Posts: 4124 JP4S'd R.

   #1 3rd January 2012, 16:57

   My car has just started idleing really low when I'm gearing down for lights etc. Almost cut's out, ive just unplugged the map sensor and the idle is perfect.
   
   Guess I need a new map sensor? or is it fine to leave it un-plugged until i get one or?
   
   cheers
2. user_29491 Saxperience Forum Bum Joined: Dec 2008 Lancs Posts: 4124 JP4S'd R.

   #2 3rd January 2012, 17:16

   Just cleaned it, and it doesn't drop the revs really low like before, but still going up and down 200rpm or so.
3. user_29491 Saxperience Forum Bum Joined: Dec 2008 Lancs Posts: 4124 JP4S'd R.

   #3 6th January 2012, 17:21

   Thought i'd bump this instead of making a new thread..
   
   I swapped the map sensor today with 1 that worked.. Idle was better.. but a few hours later it's just randomly started to have a really low idle when slowing down, sometimes resulting in cutting out.
   
   So this is my problem..
   
   Sometimes the car will start fine, and tick over properly.. When it's like this, the throttle response is normal.. and the exhaust pops alot on the downrev..
   
   Other times the car will struggle to start, EG the starter motor get's stuck like lack of battery power.. but with a few try's it will start ( only with full throttle ) then idle really weak. and the throttle response is shit, EG a fair bit of foot down = maintaining steady speed, when usually it would be picking up alot.
   
   When it's like this, it doesn't pop when down revving..
   
   Im thinking a shitty earth?
   
   As sometimes is fine, and other times not.
   
   Any idea's? like could it be a different sensor causing the problem?
   
   Gonna wire brush the earth points down to bare metal tomorrow, but anything else i could try?
   
   Cheeeers.
4. user_51379 Saxperience Forum Bum Joined: Mar 2011 plymouth Posts: 2921 mk2 VTS

   #4 6th January 2012, 17:24

   have you gave the icv a clean or as said could be a sensor.. crank or temp sensors
5. user_29491 Saxperience Forum Bum Joined: Dec 2008 Lancs Posts: 4124 JP4S'd R.

   #5 6th January 2012, 17:49

   Yeah I cleaned the ICV, but was a week or 2 ago.
   
   Defo not the earths, as ive just wire brushed them to bare metal!
   
   One of the temp sensors came off my VTR, and that engine never gave me any trouble in the 30k miles! so cant see it failing now
   
   Can't be crank, it's sparking fine, just a low idle randomly
   
   I'll try the ICV tomorrow, and clean all of the inside of the inlet!
   
   Cheers mate
6. user_29491 Saxperience Forum Bum Joined: Dec 2008 Lancs Posts: 4124 JP4S'd R.

   #6 6th January 2012, 18:39

   Just changed the ICV from my other engine, and it's still the same lol
   
   Daft question, but a weak battery wouldn't make the idle shit would it?
7. Ben_SaxoForte Saxperience Forum Bum Joined: Mar 2009 Stoke-on-trent Posts: 2640 Mk5 Golf GTTDI Mk2 VTR Project

   #7 6th January 2012, 18:47

   it might do you could try turning on your lights blowers etc and everything electrical u can find see if it makes a difference
8. user_29491 Saxperience Forum Bum Joined: Dec 2008 Lancs Posts: 4124 JP4S'd R.

   #8 6th January 2012, 18:50

   It still idle's the same when i'm putting the windows up, but they do go up REALLY slow.
   
   So i need a new battery, but that won't sort my idle problems out lol
   
   I'll try and change the water temp sensor's tmorrow, see if that makes any difference.