Hi everyone, I've only had my 2004 Autobiography 4.4 V8 for a week after searching for 2 months to find one with everything working ! It's got an annoying issue unfortunately where it's struggling to start from cold in the mornings and when I leave work in the evenings which is embarrassing. It takes around 6-10 seconds of cranking before it fires up, it sort of coughs and tries to fire during that cranking over period. Once it fires up properly it idles fine at approx 1200 rpm. Once it's been started, it'll start perfectly everytime afterwards with only 1 or 2 seconds of cranking.

I decided to replace the spark plugs over the weekend to see if that would cure the fault but it hasn't. The original plugs were very worn and old looking despite it having full service history.

It has been converted to LPG with a Stag system.

It has a new battery fitted and cranks over fast.

It drives fine with no misfiring etc. It did stall when I put it into Park once but it hasn't done that again yet.

Can anybody give me some ideas as to what could be causing this issue ?

Welcome to the Forum, hope this little issue doesn't put you off a great car.
It sounds like you have a possible fuel pump issue, Have a good read through the Forum.

So today parked at work at 8am, at 1pm turned ignition on but didn't try starting. At 5pm started it and it fired straight up no problem. Am I right in thinking that switching on the ignition at 1pm would've primed the fuel pump and brought the fuel pressure up to where it should be so when starting at 5pm there was sufficient fuel pressure to start as normal ?

Have you tried to run it on petrol just before you turn it off ? prob might be tied in with the lpg side- or at least effecting the fuel pressure keeping pressure if you know what I mean!!

Simon

Yeah I tried running it on Petrol for the last 5 mins of my journey home last night but it still struggled to start this morning.

oh well just a thought !!

I've had some further issues today to add. Drove home from work fine, pulled up put it in Park and it stalled straight away. Approx 10 mins later needed to go back out and it really struggled to start, as soon as it fired up it coughed and spluttered and cut out. It did this 3 times before eventually running as it should.

No engine light on and no fault codes present with code reader.

Any ideas ?

I don't know enough about LPG but for me I would be trying to eliminate whether its an LPG issue or not? The only time I've ever had a similar issue with my (non-lpg) it was the fuel pump failing. Mine went quite suddenly, I was coasting up to some lights and then the engine spluttered and died. It fired several times but ran lumpy for a few seconds and died and then wouldn't restart again. I couldn't hear the pump prime after that when the ignition was turned on. There was no fault code thrown.

So I would check when on petrol can you hear the pump prime when you turn the ignition on? If not and it doesn't start, do you hear the pump prime on the key turn when it does start? Lift the rear seats when you do it, so you have the best chance of hearing the pump or have someone listen with their ear in the drivers side rear wheel arch.

Could be intermittent fault with the pump, the wiring or its just on the way out. Its a reasonably expensive part but its fairly easy to replace. Current Fleet:-
2018 Discovery 5 3.0 HSE
2021 Ford Ranger Wildtrack
2019 Ford Mustang Bullitt 5.0 V8
1993 Defender 90 200TDI Pickup

Gone - not forgotten
2016 L405 4.4 SDV8 Vogue SE
2012 L322 4.4 Westminster
2004 L322 4.4 V8 Autobiography LE
2000 P38 RR 4.0 HSE (ex Clarkson test car)

I've taken the plunge and bought a BMW X5 fuel pump, a fuel filter and a fuel pressure tester to see what's going on. I'll try and fit everything over the weekend and see what happens.

I would suggest that this has all the symptoms of a failing sensor, in particular the crank sensor.
Of course a lot of problems can cause this, small fuel leak in fuel rail etc.

But i had a jag with a failing sensor and it did similar things.
Currently i have a non starter 03, but that came on very quickly. I think, it did take a few seconds to start but i assumed that was old fuel in it....

One thing I forgot to mention which makes me believe it's the fuel pump at fault is that before starting this morning, I pressed the Schrader valve in on the fuel rail and a tiny bit of fuel dribbled out and then nothing else so I'm guessing it lost all the fuel pressure overnight ??

That pretty much directs a fuel problem is at fault. But there have been a number of owners who found that it was a non return valve fault and by putting a replacement in they solved the problem.

I'm led to believe the fuel filter has a pressure regulator built into it which if faulty can allow the fuel to seep back into the tank and therefore the pressure at the rail drops.

Personally i thought it was in the pump, but i have never gone to the trouble of confirming that.

I have same model, with prinz lpg, of course run the car only on petrol while you get to the bottom of this. I had fuel pump issue, it would sometimes not start at all, and sometimes, it would, but not Rev, or drive. Bit of a nightmare to change, but there is a WIKI how that shows the procedure at top of this forum. If you are still in doubt over fuel pressure, you can buy a small device on eBay, to check it. Clip on a shredder valve. Be careful with spraying fuel from Schroeder valve, but that is a method. You could also change the fuel filter, as it's easy enough. One thing I was told, if you can thump the plastic tank sidebody, you might jar the pump into life, and if it's better the next start, it might help. The whole pump assembly is expensive, but you can buy a generic new Bosch pump on eBay for about £70. And fit it, being carful on disassembly.