Notices
General Technical
Sponsored by:
Sponsored by: CARiD

Car Wont Start any idears? [idel/hunting]

Thread Tools
 
Search this Thread
 
Old Nov 30, 2011 | 12:32 PM
  #1  
ha5ti3's Avatar
ha5ti3
Thread Starter
Scooby Regular
 
Joined: Oct 2011
Posts: 54
Likes: 0
From: edinburgh
Unhappy Car Wont Start any idears? [idel/hunting]

Been bizzy all day getting my car ready for the ra meet has been off road for a week as needed pads got them on today took it out for a spin bed them in noticed the car was haunting quite bad i took it home went up to ma m8s and back left my turbo timer on.I heard from ma house car was bearly tiking over then cut out went back out started it but was bearly tiking over tryed reving it had no effect any idears?
anyone had this happen? need this fixed in time for the meet i was told theres a way of reading the flashes as fault codes?

Ive now tried replacing the crank sensor and sensor under the alternator with no joy there is no fault code ive checked this now as well
there has been some slight idle problems on going recently and had got worse and now resulting in it not starting now ive not tried the temp sensor yet

all help/comments will be very appriciated

Last edited by ha5ti3; Nov 30, 2011 at 12:35 PM.
Reply
Old Nov 30, 2011 | 04:31 PM
  #2  
ha5ti3's Avatar
ha5ti3
Thread Starter
Scooby Regular
 
Joined: Oct 2011
Posts: 54
Likes: 0
From: edinburgh
Default

Anyone?
Reply
Old Nov 30, 2011 | 04:35 PM
  #3  
alcazar's Avatar
alcazar
Scooby Regular
20 Year Member
Liked
Loved
Community Favorite
iTrader: (2)
 
Joined: Jun 2002
Posts: 40,788
Likes: 30
From: Rl'yeh
Default

MAF?
Reply
Old Nov 30, 2011 | 07:15 PM
  #4  
Turbotits's Avatar
Turbotits
Scooby Regular
20 Year Member
iTrader: (2)
 
Joined: Jan 2004
Posts: 4,312
Likes: 0
From: Hertfordshire
Default

Maf or temp sensor and its over fueled it and flooded it. you need to establish that it has fuel at the fuel rail. injector pulsing and spark
Reply
Old Nov 30, 2011 | 07:17 PM
  #5  
sonicvr6's Avatar
sonicvr6
BANNED
iTrader: (2)
 
Joined: Aug 2011
Posts: 1,682
Likes: 0
From: at home
Default

ideal control valve
Reply
Old Nov 30, 2011 | 07:40 PM
  #6  
ha5ti3's Avatar
ha5ti3
Thread Starter
Scooby Regular
 
Joined: Oct 2011
Posts: 54
Likes: 0
From: edinburgh
Default

Tested the maf seems to be fine getting fuel and a spark as its tries to start does for bout 2 secs if patient enough at trying so its down to something like the idle control or the temp sensor i will eliminatchange them and replace maf hope that works al post my progress thanks alot for your help so far
Reply
Old Nov 30, 2011 | 07:49 PM
  #7  
alcazar's Avatar
alcazar
Scooby Regular
20 Year Member
Liked
Loved
Community Favorite
iTrader: (2)
 
Joined: Jun 2002
Posts: 40,788
Likes: 30
From: Rl'yeh
Default

Originally Posted by sonicvr6
ideal control valve
IDLE! It's an IDLE control valve It controls the car's IDLING!
Reply
Old Nov 30, 2011 | 07:51 PM
  #8  
alcazar's Avatar
alcazar
Scooby Regular
20 Year Member
Liked
Loved
Community Favorite
iTrader: (2)
 
Joined: Jun 2002
Posts: 40,788
Likes: 30
From: Rl'yeh
Default

Originally Posted by ha5ti3
Tested the maf seems to be fine getting fuel and a spark as its tries to start does for bout 2 secs if patient enough at trying so its down to something like the idle control or the temp sensor i will eliminatchange them and replace maf hope that works al post my progress thanks alot for your help so far
Hang on, hang on.............you "tested the MAF" how?

AFAIK unless you have access to sophisticated test equipment and computers, there IS NO TEST for a MAF.

Do a search on here if you don't believe me.

The old idea of disconnecting it? Rubbish.
Reply
Old Nov 30, 2011 | 07:55 PM
  #9  
sonicvr6's Avatar
sonicvr6
BANNED
iTrader: (2)
 
Joined: Aug 2011
Posts: 1,682
Likes: 0
From: at home
Default

Originally Posted by alcazar
IDLE! It's an IDLE control valve It controls the car's IDLING!
yes i'm dyslexia SORRY
Reply
Old Dec 1, 2011 | 06:03 PM
  #10  
ha5ti3's Avatar
ha5ti3
Thread Starter
Scooby Regular
 
Joined: Oct 2011
Posts: 54
Likes: 0
From: edinburgh
Default

Anyone else any advice still a non runner
Reply
Old Dec 1, 2011 | 06:12 PM
  #11  
ronjeramy's Avatar
ronjeramy
Scooby Regular
iTrader: (1)
 
Joined: May 2006
Posts: 7,833
Likes: 0
From: Cas Vegas
Default

Knackered ecu? Mine packed in and the car wouldn't start.
Reply
Old Dec 1, 2011 | 07:25 PM
  #12  
Turbotits's Avatar
Turbotits
Scooby Regular
20 Year Member
iTrader: (2)
 
Joined: Jan 2004
Posts: 4,312
Likes: 0
From: Hertfordshire
Default

MAF or idle control valve wont stop it from starting. It may run rough if theyve failed but should still start. possibly a fuel pump problem from what you describe
Reply
Old Dec 1, 2011 | 08:00 PM
  #13  
alcazar's Avatar
alcazar
Scooby Regular
20 Year Member
Liked
Loved
Community Favorite
iTrader: (2)
 
Joined: Jun 2002
Posts: 40,788
Likes: 30
From: Rl'yeh
Default

So HAVE you tried a new MAF?
Reply
Old Dec 2, 2011 | 09:11 AM
  #14  
dooda's Avatar
dooda
Scooby Regular
iTrader: (2)
 
Joined: May 2009
Posts: 235
Likes: 0
Default

Originally Posted by alcazar
Hang on, hang on.............you "tested the MAF" how?

AFAIK unless you have access to sophisticated test equipment and computers, there IS NO TEST for a MAF.

Do a search on here if you don't believe me.

The old idea of disconnecting it? Rubbish.
isnt a maf just a resister which can be tested by a decent electrical meter,

just test the resistance ? dont know for sure,
Reply
Old Dec 2, 2011 | 01:49 PM
  #15  
alcazar's Avatar
alcazar
Scooby Regular
20 Year Member
Liked
Loved
Community Favorite
iTrader: (2)
 
Joined: Jun 2002
Posts: 40,788
Likes: 30
From: Rl'yeh
Default

No, because it's supposed to vary with pressure of air passing over it, it then "meausures" the mass of the air flowing into the engine.
Mass Air Flow: MAF

So, as I said, unless you have access to accurate measuring equipment and KNOW what you are doing, there is no test.

Over the years I've seen many people come out with this idea of unplugging it with the engine running, and it's a myth.

Sorry.
Reply
Old Dec 2, 2011 | 02:21 PM
  #16  
Ciaran's Avatar
Ciaran
Scooby Regular
iTrader: (16)
 
Joined: Apr 2003
Posts: 2,771
Likes: 0
From: Curlew FPSO
Default

Originally Posted by alcazar
Hang on, hang on.............you "tested the MAF" how?

AFAIK unless you have access to sophisticated test equipment and computers, there IS NO TEST for a MAF.

Do a search on here if you don't believe me.

The old idea of disconnecting it? Rubbish.
Thats rubbish to be fair. Changed the MAF on alot of cars after using this method and solved the issue the car was having every time.

If the car is driven with the MAF working it will stall/ nearly stall when the MAF is unplugged. If the MAF has failed disconnect the plug and car continues to idle = MAF failed

The MAF is used to calculate the volume of air which is going into the engine as is the MAP sensor. A calculation is carried out for the injector duty/ignition to be set correctly for the load on the engine.
The car learns to run only using the MAP sensor when the MAF fails and therefore the car does not stall when it is disconnected.
Reply
Old Dec 2, 2011 | 07:32 PM
  #17  
alcazar's Avatar
alcazar
Scooby Regular
20 Year Member
Liked
Loved
Community Favorite
iTrader: (2)
 
Joined: Jun 2002
Posts: 40,788
Likes: 30
From: Rl'yeh
Default

Oh, right, so tuners like Harvey, David at API, Allan Jeffery are wrong then?

Whatever mate.
Reply
Old Dec 2, 2011 | 07:39 PM
  #18  
sonicvr6's Avatar
sonicvr6
BANNED
iTrader: (2)
 
Joined: Aug 2011
Posts: 1,682
Likes: 0
From: at home
Default

if it was the maf then it would through up a code has it ?
Reply
Old Dec 2, 2011 | 11:14 PM
  #19  
njberrie's Avatar
njberrie
Scooby Regular
iTrader: (1)
 
Joined: Jun 2009
Posts: 364
Likes: 0
From: blackpool
Default

maf are very prone to fail but yes do flash up cel lights have you searched around for any loose pipes ??

are the plugs getting wet when cranked over ?

if it happens to have a vta dv also check this is closing

Last edited by njberrie; Dec 2, 2011 at 11:15 PM.
Reply
Old Dec 3, 2011 | 12:46 AM
  #20  
Ciaran's Avatar
Ciaran
Scooby Regular
iTrader: (16)
 
Joined: Apr 2003
Posts: 2,771
Likes: 0
From: Curlew FPSO
Default

Originally Posted by alcazar
Oh, right, so tuners like Harvey, David at API, Allan Jeffery are wrong then?

Whatever mate.
Not saying they are wrong. Maybe through experience they have found it is not a reliable way of diagnosis thats up to them.
I will continue to use the disconnection method as it has worked for me so far
Reply
Old Dec 3, 2011 | 12:58 AM
  #21  
stevie2011's Avatar
stevie2011
Scooby Regular
iTrader: (1)
 
Joined: Oct 2011
Posts: 171
Likes: 0
From: N.ireland
Default

coilpack leads or coilpack!!!!!!!
Reply
Old Dec 3, 2011 | 10:42 AM
  #22  
alcazar's Avatar
alcazar
Scooby Regular
20 Year Member
Liked
Loved
Community Favorite
iTrader: (2)
 
Joined: Jun 2002
Posts: 40,788
Likes: 30
From: Rl'yeh
Default

Originally Posted by Ciaran
Not saying they are wrong. Maybe through experience they have found it is not a reliable way of diagnosis thats up to them.
I will continue to use the disconnection method as it has worked for me so far
Jeez, I wish splitpin was here so he could put this one to bed AGAIN.
Reply
Old Dec 3, 2011 | 11:00 AM
  #23  
ha5ti3's Avatar
ha5ti3
Thread Starter
Scooby Regular
 
Joined: Oct 2011
Posts: 54
Likes: 0
From: edinburgh
Default

Lol settle down boys stick to the subject thanks for helping everyone by the sounds of it i need to replace everything i wasent wanting to buy all auxillarys for a subaru just the faulty one
Reply
Old Dec 3, 2011 | 04:06 PM
  #24  
joz8968's Avatar
joz8968
Scooby Regular
15 Year Member
iTrader: (13)
 
Joined: Aug 2006
Posts: 23,764
Likes: 9
From: Leicester
Default

But the unplugging thing at idle is ONLY measuring airflow/voltage at partial vaccum/idle - and NO other load/rpm situation.

At idle it's not an issue, as there's no arduous conditions happening for 'the engine to worry about'.

If, however, the supposed 'good' MAF's sensor dropped voltage at high load/rpm or WOT, then it could be curtains for the motor due to transient lean AFRs! This is what the "unplugging at idle test" CANNOT determine.

As alcazar has eluded to, Splitpin has covered this in detail in many threads...

Last edited by joz8968; Dec 3, 2011 at 04:11 PM.
Reply
Old Dec 3, 2011 | 06:40 PM
  #25  
alcazar's Avatar
alcazar
Scooby Regular
20 Year Member
Liked
Loved
Community Favorite
iTrader: (2)
 
Joined: Jun 2002
Posts: 40,788
Likes: 30
From: Rl'yeh
Default

Thanks joz, I need to copy that explanation.
It's amazing how many times you see that myth come up. I wonder how many engines have gone pop because of it?
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Iqy7861
Engine Management and ECU Remapping
22
Oct 12, 2015 09:21 AM
ossett2k2
Engine Management and ECU Remapping
15
Sep 23, 2015 09:11 AM
ossett2k2
General Technical
9
Sep 13, 2015 09:35 AM
blackandz
General Technical
0
Sep 12, 2015 07:01 PM
alcazar
Other Marques
9
Sep 9, 2015 05:42 PM




All times are GMT +1. The time now is 05:20 AM.