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Omega Help Area => Omega General Help => Topic started by: Shimmy on 27 June 2011, 14:34:11

Title: Won't start when hot
Post by: Shimmy on 27 June 2011, 14:34:11
Hi there

Just had the car recovered by the RAC to a garage after spending at least an hour trying to solve/diagnose the problem.  We reckon either crank/camshaft sensor or fuel pump relay or related to that.  Tried both my bluetooth code reader and the RAC code reader, NO codes stored.  Which is strange.

Problem first started on Saturday 100 miles from home, starting from motorway services the car took 3/4 turns before it started after a pause (hot day).  No issues driving home as it was all dual carriageway, water temp was 85c.

Drive today to the post office, turns first key but upon reaching a busy junction the engine cuts out when coasting up to the lights (not a great place!).  Car wouldn't start at all, plenty of fuel and the battery is 6 months old and plenty of charge.  After a lot of fuss (don't get me started) I get the RAC man to come, it starts after a couple turns and we stop at pubs car park nearby where it cuts out again.  As said, no codes to speak of.  RAC guy tries bypassing the fuel pump relay and it still won't turn over.  So is it likely to be crank sensor, cam shaft sensor or something fuel related?  Definitely seems heat related though.  Never had any starting issues in the past.

Also to bear in mind, the car came back from the garage on Friday after the aux belt was replaced when getting the air con fixed which needed a new compressor and belt.

Cheers.
Title: Re: Won't start when hot
Post by: Kevin Wood on 27 June 2011, 14:45:13
The symptoms are often seen with a failed crank sensor, although usually, but not always, that's accompanied by a 0335 code.

They can often fail after the wiring has been disturbed, too. It gets brittle with the heat. I wouldn't be at all surprised if it were the crank sensor.
Title: Re: Won't start when hot
Post by: Shimmy on 27 June 2011, 22:32:58
Yeah think I'm just gonna get a crank shaft sensor in the morning from Vauxhall and ask the garage to try fitting that first before trying any diagnosis.  If it's not that I'll have it future just in case.

Any other ideas chaps?
Title: Re: Won't start when hot
Post by: henryd on 27 June 2011, 23:42:54
When was your fuel filter last changed?,I had a car in today with a similar fault,no codes stored but after getting held up in traffic engine would cut out and wouldn't restart for 20 mins or so and had been doing this for a couple of weeks.I replaced the fuel filter and problem has gone(owner got stuck in traffic on his way home without issue).
Title: Re: Won't start when hot
Post by: Shimmy on 28 June 2011, 00:14:16
Quote
When was your fuel filter last changed?,I had a car in today with a similar fault,no codes stored but after getting held up in traffic engine would cut out and wouldn't restart for 20 mins or so and had been doing this for a couple of weeks.I replaced the fuel filter and problem has gone(owner got stuck in traffic on his way home without issue).

New GM fuel filter fitted 2 months ago.
Title: Re: Won't start when hot
Post by: henryd on 28 June 2011, 00:22:22
Quote
Quote
When was your fuel filter last changed?,I had a car in today with a similar fault,no codes stored but after getting held up in traffic engine would cut out and wouldn't restart for 20 mins or so and had been doing this for a couple of weeks.I replaced the fuel filter and problem has gone(owner got stuck in traffic on his way home without issue).

New GM fuel filter fitted 2 months ago.

bang goes that theory then :D ;D ;D,hope the crank sensor sorts it for you :y
Title: Re: Won't start when hot
Post by: trainmanone on 28 June 2011, 07:17:20
disconnect maf sensor ,had similar problem not so long ago no codes came up aa disconnected maf ran okish but got me home  :y
Title: Re: Won't start when hot
Post by: Shimmy on 28 June 2011, 12:55:13
Quote
disconnect maf sensor ,had similar problem not so long ago no codes came up aa disconnected maf ran okish but got me home  :y

Wasn't running lumpy at all, just suddenly switched off when approaching busy junction and then again later when parked up.  Then won't start unless left for 10/15mins.

I replaced the MAF with a new GM part 8/9 months ago.
Title: Re: Won't start when hot
Post by: cem_devecioglu on 28 June 2011, 12:58:58
"Problem first started on Saturday 100 miles from home, starting from motorway services the car took 3/4 turns before it started after a pause (hot day).  "

if its not the crank sensor (in my case was not), 

here is a short checklist

fuel pump relays, fuel pump, fuel regulator..

tried fuel pressure drop tests and I'm on a trial fuel pump for 2 days ..and will try another regulator...

Title: Re: Won't start when hot
Post by: Shimmy on 28 June 2011, 17:24:38
As thought it was the crank sensor!

Any idea how long these typically last as I've ordered a spare anyway, worthwhile?