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Vauxhall Astra 1.7 Z17DTH 2007 - Difficult to start when warm, codes P0621, P0500 #

Posted by Liam Hall on June 11, 2012, 7:56 am

Year of Manufacture *: 2007 '07
Engine Size and Code *: 1.7 Z17DTH
( Optional ) Scanner Used: Solus Ultra
( Optional) Fault Codes: P0621 Alt, L Line circuit fault/implaus, P0500 VSS

Hi all,

Bit of a strange one here (to me anyway)

We have just bought this car for my grandma, from a used car dealer.

It was fine for the first week, but then developed a starting issue when warm, we took back to the dealer and he had the crank sensor replaced, which seemed to cure the fault.
However, a few weeks on, when the car is warm it struggles to start, and sometimes tries to run and just shudders at 750ish rpm for a few seconds.

I have retrieved the codes, VSS seems an unlikely culprit, (?) so I was leaning towards the alternator code.

My question if anyone can answer it is, has anyone seen this before, and what would you do next?

It has me completely stumped.
I have looked at data, fuel pressure mirrors the desired so at this point I am discounting fuel as a cause, especially as this fault is only from hot.

Sorry for long post, but a bit of background usually helps.

Liam.

Re: Vauxhall Astra - difficult/non start when warm P0621, P0500

Posted by Tony Ludford <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT5539' width='330' height='300' border=0 style='border:none;'> on June 12, 2012, 7:50 am, in reply to "Vauxhall Astra - difficult/non start when warm P0621, P0500 "
Tony Ludford

Can you scope the crank signal from hot?
As the first question I'd be asking, is what brand was the crank sensor....

Has it got a Dual mass, is that failing?

Re: Vauxhall Astra - difficult/non start when warm P0621, P0500

Posted by Liam Hall <iframe src='https://members.boardhost.com/ukautotalk8/info/user=ukat3033' width='330' height='300' border=0 style='border:none;'> on June 12, 2012, 6:41 pm, in reply to "Re: Vauxhall Astra - difficult/non start when warm P0621, P0500 "
Liam Hall

Fitted a genuine (bosch in gm box) crank sensor, car still same.

I wanted to rule out a faulty part completely.
Also, no scope!

Liam.

Re: Vauxhall Astra 1.7 Z17DTH 2007 - Difficult to start when warm, codes P0621, P0500 #

Posted by Dave Yates <iframe src='https://members.boardhost.com/ukautotalk8/info/user=ukat3449' width='330' height='300' border=0 style='border:none;'> on June 13, 2012, 7:10 pm, in reply to "Vauxhall Astra 1.7 Z17DTH 2007 - Difficult to start when warm, codes P0621, P0500 #"
David Yates

Does it start with a tow had a couple not cranking fast enough when hot first was starter second battery

Re: Vauxhall Astra 1.7 Z17DTH 2007 - Difficult to start when warm, codes P0621, P0500 #

Posted by Liam Hall <iframe src='https://members.boardhost.com/ukautotalk8/info/user=ukat3033' width='330' height='300' border=0 style='border:none;'> on June 15, 2012, 11:21 am, in reply to "Re: Vauxhall Astra 1.7 Z17DTH 2007 - Difficult to start when warm, codes P0621, P0500 #"
Liam Hall

Dave;
Always starts, but with prolonged cranking.

I'm suspecting injectors now, will do a leak off test and take it from there.

Has anyone had injectors with more backleak when hot?

Liam.

Re: Vauxhall Astra 1.7 Z17DTH 2007 - Difficult to start when warm, codes P0621, P0500 #

Posted by Dave Yates <iframe src='https://members.boardhost.com/ukautotalk8/info/user=ukat3449' width='330' height='300' border=0 style='border:none;'> on June 15, 2012, 7:31 pm, in reply to "Re: Vauxhall Astra 1.7 Z17DTH 2007 - Difficult to start when warm, codes P0621, P0500 #"
David Yates

It was cranking speed that i was referring to if it starts instantly with a fast tow could be cranking too slow.

Re: Vauxhall Astra 1.7 Z17DTH 2007 - Difficult to start when warm, codes P0621, P0500 #

Posted by liam hall <iframe src='https://members.boardhost.com/ukautotalk8/info/user=ukat3033' width='330' height='300' border=0 style='border:none;'> on June 26, 2012, 7:59 pm, in reply to "Re: Vauxhall Astra 1.7 Z17DTH 2007 - Difficult to start when warm, codes P0621, P0500 #"
Liam Hall

Quick update on this.

Carried out leak off tests cold and hot, and there was no difference in results.

Stuck now to be honest......

Liam.

Re: Vauxhall Astra 1.7 Z17DTH 2007 - Difficult to start when warm, codes P0621, P0500 #

Posted by Mark Carter <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1428' width='330' height='300' border=0 style='border:none;'> on June 27, 2012, 9:00 pm, in reply to "Re: Vauxhall Astra 1.7 Z17DTH 2007 - Difficult to start when warm, codes P0621, P0500 #"
Mark Carter

>>> I'm suspecting injectors now, will do a leak off test and take it from there.<<<

Question: What diagnostic results send you down the injector route?

Regards Mark

Modern cars, Its all wizardry and witchcraft

Re: Vauxhall Astra 1.7 Z17DTH 2007 - Difficult to start when warm, codes P0621, P0500 #

Posted by liam hall <iframe src='https://members.boardhost.com/ukautotalk8/info/user=ukat3033' width='330' height='300' border=0 style='border:none;'> on June 28, 2012, 8:57 pm, in reply to "Re: Vauxhall Astra 1.7 Z17DTH 2007 - Difficult to start when warm, codes P0621, P0500 #"
Liam Hall

At the moment Mark, my thoughts are all that is pointinig me toward the injectors, as I suspected fuel pressure.

I have actually fixed this today (was on here to update!)
The fault was the IMV on the pump, breaking down when hot.

The odd thing was that it would sometimes start, but run at say 650-750rpm, with alt light on etc, obviously due to the lack of fuel.

What I need is a sealed rail test kit desperately.

Unfortunately I don't have the funds available, but its way up there on my priorities!

Liam.

Re: Vauxhall Astra 1.7 Z17DTH 2007 - Difficult to start when warm, codes P0621, P0500 #

Posted by Mark Carter <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1428' width='330' height='300' border=0 style='border:none;'> on June 28, 2012, 11:04 pm, in reply to "Re: Vauxhall Astra 1.7 Z17DTH 2007 - Difficult to start when warm, codes P0621, P0500 #"
Mark Carter

Well done on the fix, but you are right the proper test equipment will help a lot.

We all have a wish list

Mark

Modern cars, Its all wizardry and witchcraft

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