Hard to start Au.

GASXD · 19-02-2010, 07:58 PM

Hi all, I have an au series 2, six. She has always been a tad lazy to start and the last few days she just cranks for a while then starts and runs fine. Now if i turn the key on and off a few times (5) to let it prime the line she starts first go. It has new coil pack new leads and plugs however it seems that its lossing pressure and it takes a bit to get it to prime. Pehaps its lossing pressure at the rail via the pump and there is no fuel at the rail upon startup???
Cheers
Doug.

GASXD · 20-02-2010, 10:07 AM

Hi all, i'v given it some more thought.
1. spark is all ok.
2. Its not starving for fuel, so this ruels out fuel filter or blocked fuel line.
3.When started it runs fine and if restarted within the hour, it starts first go.
My guess is that the fuel pressure regulator is bleeding off rail pressure over time, i.e 10 to 12 hours or overnight. This would be a cause of hard starting due to not having sufficient fuel rail pressure upon start up. It would also explain why it starts first go when started say 20 minuets beforhand. Again I'm thinking fuel reg due to the fact that, when the ignition is switched on, say 4 times the fuel pump runs its prime cycle and therefor pressurises the rail and allows the engine to fire up first go, which it does. So thats what I'v come up with, but then again I'm no expert. Anyone have any thoughts on this?
Cheers
Doug.

Mr Hardware · 20-02-2010, 11:09 AM

There could be some evaporation going on somewhere. How long since you replaced your fuel filter? What sort of fuel do you run?

GASXD · 20-02-2010, 11:46 AM

Hi Hardware, I'm running 95. Did a major service about a month back and a fuel filter was one of the things i replaced.
Cheers
Doug.

illusivedreams · 20-02-2010, 07:41 PM

Your injectors could be dirty and leaking.
Check if when the car start it blows a bit of smoke .

GASXD · 21-02-2010, 12:05 PM

Hi Illusive, I'v checked for smoke at start up and its all clear. If i had a leaking injector would it not run rough on startup like a leaking head gasket. Also it could cause a slight but noticable rough idle?
I'v done a test over night by clamping the fuel supply line with brake line clamps. My reasons for this are that, if its leaking back through the check valve in the pump i would be lossing line pressure. I started it this morning and on the second crank it started. Now without the line being clamped the cranking time almost sent my battery flat. This to me says fuel pump, i'v checked for leaks and none appear to be visable nor can i smell any. Had i had starting trouble this morning i would have clamped the fuel return line off the reg but it seems to have done the trick. My question is, is the check valve located in the fuel pump on an AU or is it part of housing that it sits in located in the tank? Once again thanks to all for your input.
Cheers
Doug.

Pict · 21-02-2010, 12:54 PM

You're troubleshooting skills are intense.

Keen to see how this goes, my XR6 stumbles a bit on start up, and I cant for the life of my figure it out.

webby_191189 · 21-02-2010, 04:37 PM

intake manifold gasket?

XRATE-UTERUS · 11-12-2010, 08:58 PM

what was the outcome of this?

au11futura · 12-12-2010, 01:06 PM

yeh would like to see outcome too.

GASXD · 13-12-2010, 10:37 AM

Hi all,

Well she's been going like a train eversince I sorted this problem. What it turned out to be was the fuel lines that are benenth the passengers side footwell.
Where the plastic lines come from the engine bay down to the metal line that runs under the car.
The plastic clip that connects to the metal section wasn't sealing propperly and causing pressure to bleed of over time.
How i discoverd this was one morning when letting my car warm up it had a strong petrol smell from the engine bay.
I then stuck my head under to see it dripping from the connector.
I gave the conections a wiggle and a gentle push (as if i where trying to connect it onto the line) and that seemed to stop the leak and never had any dramas since.
Now I never came across a leak when I was looking around but anyhow there you go. thanks again to all for you'r thoughts and I hope this helps out somone who may have similar troubbles.

Cheers,
Doug.

au11futura · 20-12-2010, 10:36 PM

good stuff mate shold add it to the common probs & trouble shooting section of au's.

will check mine tomorrow ha just to be safe..