Ve Omega Rough Start and idle in hot weather

[Smithky]

Hi all my 2008 ve commodore omega struggles to start and will sometimes stall when ever the engine has not been ran for several hours and it is hot weather say 35 + give it a little bit of throttle and runs fine after only does it in hot weather not cold any ideas thanks.

 

[slepar]

My miss's Ve Calais has the same problem, only happened sometimes for us though, can't figure it out yet

 

[Smithky]

yeah and there are no error codes either

 

[Smithky]

Anyone have any ideas?

 

[VK SL 3800]

Could be a slow fuel pressure leak/ air getting into the rail.

My first check would be fuel pressure but also have a look what the air temp sensors and few things are reading which is a bit hard from home without a scantool.
A mechanic can often tell by listening what is going on, like starving for fuel or having a spark related miss etc so problems like this are hard to diagnose over the internet.

Try cycling the key a few times before starting to prime the fuel system up as much as possible, Non SIDI Alloytecs run a return less rail so any air will still be trapped and be vented out the injectors, SIDI ones may be the same but im not sure.

 

[Smithky]

i have a scan tool

 

[Smithky]

what temp should i be looking for ?

 

[VK SL 3800]

Engine coolant temp, air intake temp. Cold start should be ambient in the air intake providing its not in the sun, coolant temp should be be a little lower.

Check for black smoke or other out the exhaust also.

 

[Capsule]

I would also check the evap solenoid. I know a faulty one can cause warm start issues. Is it clicking like crazy when idling?

 

[Wideglide]

2008 ve Calais runs rough in temperatures above 38 deg . Dosnt do it all the time and eventually clears . Any suggestions