Car Wont Start any idears? [idel/hunting]
30 November 2011, 12:32 PM
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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
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; 30 November 2011 at 12:35 PM.
30 November 2011, 07:40 PM
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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
It controls the car's IDLING!
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30 November 2011, 07:51 PM
#8
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
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.
01 December 2011, 07:25 PM
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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
02 December 2011, 09:11 AM
#14
just test the resistance ? dont know for sure,
02 December 2011, 01:49 PM
#15
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.
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.
02 December 2011, 02:21 PM
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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.
02 December 2011, 11:14 PM
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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
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; 02 December 2011 at 11:15 PM.
03 December 2011, 12:46 AM
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I will continue to use the disconnection method as it has worked for me so far
03 December 2011, 11:00 AM
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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
03 December 2011, 04:06 PM
#24
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...
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; 03 December 2011 at 04:11 PM.
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