Trouble starting. Where to look?

JustAnotherSaver

a.turner wrote: »

When did you last change it?

the fuel tank? Never.


Google Astra H fuel filter. It's a non changeable part, unless you change the fuel tank itself.

Begsey

It's more diesels I've had, but I'd always check the charging voltage first.
I like to see around 14.3-14.4v.

If that's ok, I'd see if there was any battery draw/parasitic drain. Test meter set to amps, negative connection removed, clip onto the battery terminal and the removed connection. See what it says.

Anything more than around 300maA is likely to be a problem. You need to let the car go to "sleep" though which could take up to 15 mins in some cases. Tape down the bonnet open switch if it has one (assuming under bonnet fuse box), and keep the doors closed.

If you're over 300mA, start pulling fuses and/or relays until the reading goes down. Whatever drops it is your problem.

The new battery at Xmas may have hidden a parasitic drain issue for a while.

JustAnotherSaver

DoaM wrote: »

1. measure the battery voltage with the engine off (should be around 12V)
2. when the engine is being started (should remain around 12V - if it dips significantly then the battery may be suspect)
3. when the engine is running (should be around 14V - if a lot lower or higher then the alternator is suspect)

Well i plugged opcom in and it was reading 12.something just before i started it.
Started it up and the reading dropped to 10.something instantly going to 11.something and within a second or so it sat at 14.4v until i turned it off

DoaM

Not sure if sub-11v on starting is expected. I'd hope the voltage would stay at 12v as the battery should be a far larger source than the load connected.

JustAnotherSaver

I don't know whether it makes a difference but the car didn't have any trouble starting when i got those figures either.

Apodemus

EdGasketTheSecond wrote: »

Re. 'Trouble starting. Where to look?

I'd begin under the bonnet

I’d start by reading the codes, so for me it would begin under the dashboard!

Apodemus

JustAnotherSaver wrote: »

the fuel tank? Never.


Google Astra H fuel filter. It's a non changeable part, unless you change the fuel tank itself.

Quite so, but unfortunately Mr Google also seems to suggest replacement at 40k miles...

Begsey

JustAnotherSaver wrote: »

Well i plugged opcom in and it was reading 12.something just before i started it.
Started it up and the reading dropped to 10.something instantly going to 11.something and within a second or so it sat at 14.4v until i turned it off

I'd be happy with that and go on to parasitic drain.
I'd say the alternator is good, and I'd discount the battery as it's not very old.

My MK 2 astra, the battery drain was down to the boot light, which was a common astra fault
back then.