Alloytec intermittent fault - not starting.

[Benboy]

Because of the nature of the problem it is difficult to search for(specific) previous discussions hence my reason for starting a new thread.
Commodore 2007 VZ Alloytec.

Vehicle serviced as per Holden's schedule.

Recent trip to Dealer for servicing and they not able to replicate or identify existence of a problem (code etc). Basically they were of no help.

Nature of problem:
Generally when the engine is cold it is unusual for problem to occur.

Once vehicle has been driven and engine warm vehicle is reluctant to fire (start).

On a couple of occasions problem has been evident when engine cold !!

Sometimes it takes 3 - 5 attempts (i.e. turn key and engage starter for 5 - 10 seconds on each occasion).

Sometimes it starts after second or third attempt.

There is no real pattern to the occurrence of the problem.

I have suspected the Crankshaft Sensor. They can and do have intermittent faults once engine heat/soak heats them up. Holden Service adamant that if it was the Crankshaft Sensor, then a Fault Code would have been evident !!

Any usefull suggestions greatly appreciated.

 

[gungazza]

yer no codes makes it hard ,what about cam sensors, i have just done my cam chains,getting cam sensors code, car is going good. no probs I changed sensors with new ones. now 02 sensor I changed them 3 yrs ago if I clear codes goes ok turn it off codes come back .got me lol

 

[99notout]

It's not an injector(s) bleeding down when hot is it? When it does start do you get a strong smell of fuel out the exhaust?

 

[delcowizzid]

Ecu is probably on the way out

 

[Benboy]

It's not an injector(s) bleeding down when hot is it? When it does start do you get a strong smell of fuel out the exhaust?

Thanks for your reply. There is no strong smell of fuel on engine starts. It starts and runs normally.

 

[Benboy]

yer no codes makes it hard ,what about cam sensors, i have just done my cam chains,getting cam sensors code, car is going good. no probs I changed sensors with new ones. now 02 sensor I changed them 3 yrs ago if I clear codes goes ok turn it off codes come back .got me lol

Thanks for your suggestions. As I previously mentioned, NO CODES are being generated or displayed.

 

[Benboy]

Ecu is probably on the way out

Thanks for your reply. A 'bold' statement. Are there any other obvious indicators to support your theory ?

 

[rambunctious]

How old is the remote ??
Might be time to change the battery in the remote.

My VZ wagon has been free of start problems since I put a new battery in the remote, but last week I decided to start using the older remote and yesterday the car started then stopped instantly so I might have to put a new battery in the old remote as well.

edit.. I just read the op again so next time it plays up remove the key and then have another go because this is what my wagon was doing before I replaced the remote battery, and I found at the time if I removed the key then tried again it would start..

 

[gungazza]

is the engine ratterly . mine was hard to start 2,3 secs don't sound a lot but ive done the chains and starts straight away how many klms I went to work this morning no codes come home lol cam code lol but the car goes great got me

 

[Fu Manchu]

The frustrating thing with this stuff is, to get anywhere, a diagnostic tool needs to be connected.
The procedures take time and time is often not what the workshops have or want to hand over in favour of simpler servicing jobs that generate more profit.

I can get so far with computer based diagnostic stuff but the more I think about it, a $500-$600 outlay on a tech 2 over the years starts looking good. Then we can take our sweet time to poke around and explore the options without someones clock ticking.