Hard starting?

[VYMAD]

Hey guys, having some trouble with the VY V6. Lately when I crank it over to start, it will either fire and then die, or wind over for a few seconds and then stop cranking all together. Turn key off and try again a few times and will finally start. Battery is not that old and doesn't sound lazy. It has new plugs, leads, fuel filter, air filter, I always run it on premium and occasionally run some injector cleaner through it. Once it has started it runs as per normal, no power loss, no miss etc Thoughts?
Oh and sometimes it's not doing the above at all, as in it just starts normally first go.

 

[Calaber]

Intermittent faults are usually the hardest to diagnose, expecially without seeing the car. I would have to go with an electrical fault. Perhaps the coil pack or sensor is faulty. Do you have any error codes showing?

 

[VYMAD]

There's no warning lights on the dash and I don't have access to a tech 2.

 

[db_notso]

FIRST check battery terminals are tight and acid isnt leaking from the battery

you need a multimeter
on "volts setting"

put meter onto battery
with everything off it should read around 12 volts
when "cranking/starting" it should NOT be less than 10 volts
with car running and everything off it should be around 14 volts
then turn everything on you can lights etc it should still read about 14 volts

IF is less than 13.00 volts when engine running all off then have altenator internals checked

If is less than 13.00 volts when engine running and all lights etc on check altenator brushes (or altenator diodes gone)

IF reads less than 10 volts while cranking try jump starting the car and see if still drops below 10 volts (with two batterys on it)
if it does drop below ten volts check wiring on the starter motor is tight
if wiring tight likely need to replace starter

if everything above passes the tests....
swap starter relay with another relay in the engine fuse box and try to crank again

if all is ok suspect starter solenoid is worn out take it to auto electricians to have solenoid replaced

when solenoid fails
will crank at normal speed but will miss like 1, 2 , gap, 4, etc
basically what happens is the "switch" inside the starter solenoid doesnt contact properly as it is dirty/worn on a certain spot
as the switch operates it moves like a rotation of its contacts
so the switch flicks once but cant stay engaged long enough to spin up the starter motor

try that stuff before going into possible faults with ignition signal good luck!~

 

[VYMAD]

Thank you. I shall get hold of a multimeter and give it a go. Cheers.

 

[TMM]

If it stops cranking while you are still turning the key its either the key/immobilizer or the starter motor. If it were anything else it would just keep cranking forever until the battery goes flat.
If the key is dead or there is bad electrical contact with the barrel, the immobilizer will cut the starter motor, fuel and spark after a few cranks.

 

[VYMAD]

If it stops cranking while you are still turning the key its either the key/immobilizer or the starter motor. If it were anything else it would just keep cranking forever until the battery goes flat.
If the key is dead or there is bad electrical contact with the barrel, the immobilizer will cut the starter motor, fuel and spark after a few cranks.

Tried both keys, same thing. Seems to fire for a second and then stop, turn key off/on a couple of times and if I'm lucky it'll start. I wiped the ring on the ignition barrell with my finger before, maybe armour all on it? I dunno, waiting to get hold of a multimeter and check out as above post says. Tearing my hair out.
Have been researching on this forum and have come up with possible:
;CAS
;Coil packs
;Bad earth
;Key signal, as you say
;DFI.
Still open to any more suggestions. Have checked all vaccuum hoses etc, starter motor wiring, swapped engine start relay.

 

[PRAVX II S]

sounds to me like the starter solenoid is burned out. But first.
Check for power at the starter solenoid the thin wire that triggers the starter. What you need to do is get someone to crank the car and test this wire for power. This power should not go away until the key is back to the reds position.
If the power disappears or is not there while trying to start it the problem lies further back like starter relay, inhibitor switch if auto,even the factory security,
But if there is a constant power there then inspect the the thick power wire from the battery to the starter make sure there is a good connection at both points.
You should also check voltage drop from the battery positive to the starter positive should be no more the 0.5 on the multi-meter.
If this is ok then i would change the starter motor.

 

[VYMAD]

sounds to me like the starter solenoid is burned out. But first.
Check for power at the starter solenoid the thin wire that triggers the starter. What you need to do is get someone to crank the car and test this wire for power. This power should not go away until the key is back to the reds position.
If the power disappears or is not there while trying to start it the problem lies further back like starter relay, inhibitor switch if auto,even the factory security,
But if there is a constant power there then inspect the the thick power wire from the battery to the starter make sure there is a good connection at both points.
You should also check voltage drop from the battery positive to the starter positive should be no more the 0.5 on the multi-meter.
If this is ok then i would change the starter motor.

Ok, thanks, will do. I have just been over at a mates place doing the multimeter tests from a few posts above and that all passed. I have found, however that it seems if I put the key in the ignition and press unlock again, the engine starts first go! I have stopped and started a few times today at shops, etc, and each time this method seems to be starting it. So, maybe immobiliser related? I will do these checks that you have suggested and thanks for the quick reply.

 

[VYMAD]

Well, I've booked in to Holden on Tuesday the 4th to pull any codes that have been logged. Still starts every time if I press unlock again while key is in the ignition. So I am thinking the problem could be in the factory security.
Anyone know if this will have logged a code? Not real happy about going to Holden, but after a bit of ringing around, they are the only ones I've found with a tech 2. $50 and I should then know if any codes come up. 7 years and never had it checked so probably worthwile, I'm hoping.