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VX commodore starts sometimes

HoldenHoon

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Hey everyone. I put up a thread earlier about my VX V6 that only starts sometimes. It still has been happening after I have changed starter motor, relay, coils, leads, plugs and Egr module. For those of you who don’t know about this situation, I can start the car like normal. After starting and switching it off a few times it will no longer crank when I turn the key. Everything just dims like normal when you usually go to crank it over. It also has a new battery so I know it’s not voltage related. What I’ve found out is that if it bridge the main power wire on the starter motor to the trigger wire it will work again. It just won’t start with the key. So, in fewer words, the car does run fine it’s just every now and then it won’t want to crank. Sometimes it’ll work after 5 minutes, sometimes after 1 hour or so. Any ideas? Was thinking CAS but apparently this isn’t a symptom of it. Any help would be greatly appreciated. Thanks!
 

Lex

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Hey everyone. I put up a thread earlier about my VX V6 that only starts sometimes. It still has been happening after I have changed starter motor, relay, coils, leads, plugs and Egr module. For those of you who don’t know about this situation, I can start the car like normal. After starting and switching it off a few times it will no longer crank when I turn the key. Everything just dims like normal when you usually go to crank it over. It also has a new battery so I know it’s not voltage related. What I’ve found out is that if it bridge the main power wire on the starter motor to the trigger wire it will work again. It just won’t start with the key. So, in fewer words, the car does run fine it’s just every now and then it won’t want to crank. Sometimes it’ll work after 5 minutes, sometimes after 1 hour or so. Any ideas? Was thinking CAS but apparently this isn’t a symptom of it. Any help would be greatly appreciated. Thanks!
Start relay?
 

lout

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you need a basic understanding if you are going to do your own maintenance
no crank could be, ignition switch, key reader/ remote, park/neutral switch, starter relay, starter motor/solenoid ecu, fuses/fusible link, and any wiring between and battery condition
spark plugs, crank sensors coils egr have nothing to do with cranking
what you have is called an intermittent no crank
not to be confused with crank, no start
 

HoldenHoon

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Ye
you need a basic understanding if you are going to do your own maintenance
no crank could be, ignition switch, key reader/ remote, park/neutral switch, starter relay, starter motor/solenoid ecu, fuses/fusible link, and any wiring between and battery condition
spark plugs, crank sensors coils egr have nothing to do with cranking
what you have is called an intermittent no crank
not to be confused with crank, no start
Yes I know that but I just listed the things I changed incase anyone was going to ask. As I said I’ve changed the starter motor. Changed relays. Checked for power going to the relay when it doesn’t want to start which there is power.
 

lout

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if you can force the car to fault
or test when it is faulting
at the start relay
pin 30 constant bat pos
pin 85 ignition switch, pos when cranking
pin 86, negative from ecu, through park/neutral switch
pin 87 to starter motor solenoid (thin wire), if using a multimeter should be around 20 ohms resistance to ground
 

HoldenHoon

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if you can force the car to fault
or test when it is faulting
at the start relay
pin 30 constant bat pos
pin 85 ignition switch, pos when cranking
pin 86, negative from ecu, through park/neutral switch
pin 87 to starter motor solenoid (thin wire), if using a multimeter should be around 20 ohms resistance to ground
Yeah sweet I’ll give this a go and let you know. Thanks heaps.
 

HoldenHoon

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When changing, did you use the correct relay?
Lot of people think relays are all the same.
I just swapped it out with my other VY commodore. These relays have numbers labeled on them. Like 0360 etc. what number is the one for the start relay supposed to be?
 
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