Starting problem

[skoff]

Hi All,

I currently have an annoying starting problem with my 2005 CV8 (big boot).

When I try to start the car it fires up briefly and then dies. Occasionally it doesn't even fire up at all. After a few attempts it does eventually start and stay started...

I immediately thought that the battery was probably on the way out, so I changed that today, but it seems to have the same problem.

Any ideas what to look at next?

[MatrixXXx]

sound like an air or fuel problem, is the throttle body clean or full of soot? last time fuel filter changed? any fault codes? what are the plugs like?

[S800VXR]

Had some experiance recently with fuel systems so check your non return valve in the fuel line is not letting by. It's purpose is to hold line pressure to give a good hit before the line pressure gets up. If it lets by the injectors open on a fresh start but fk all goes in till the line pressurises up fully. Also worth checking the fuel pump pressure output in case that's caput although it would run shyte once running if it were faulty.

[ringram]

I recon check plugs.

I use Occam's Razor

[SturdyHSV]

S800VXR said:

Had some experiance recently with fuel systems so check your non return valve in the fuel line is not letting by. It's purpose is to hold line pressure to give a good hit before the line pressure gets up. If it lets by the injectors open on a fresh start but fk all goes in till the line pressurises up fully. Also worth checking the fuel pump pressure output in case that's caput although it would run shyte once running if it were faulty.

On this note, you could try turning the key to ignition and listening how long the pump stays on for, it should be very quick to build pressure. See if leaving it on ignition for a little while then cranking if it starts first time.

[skoff]

Thanks chaps, a good list of things to check... I will get back to you on what I find.

[skoff]

S800VXR said:

Had some experiance recently with fuel systems so check your non return valve in the fuel line is not letting by. It's purpose is to hold line pressure to give a good hit before the line pressure gets up. If it lets by the injectors open on a fresh start but fk all goes in till the line pressurises up fully. Also worth checking the fuel pump pressure output in case that's caput although it would run shyte once running if it were faulty.

I think the non return valve might be the problem. If I turn the ignition on and wait for the fuel pump noise to stop, then ignition off and turn on, then it starts first time. The car runs beautifully when it's going, so I am hoping that it's not the fuel pump.

Is the non-return valve an easy thing to replace? I'm guessing they aren't too difficult or expensive.

[skoff]

Well I think I have figured out the problem, and to be honest, I feel slightly foolish.

I gave Monkfish a call to ask about the non-return valve thingy, and they told me that they had never had to replace one, and that this sort of an issue was usually caused by the alarm, or some electronic control box or other. They asked me to see if the car was spitting out any error codes and come back to them.

Then on Friday night driving home, my alarm started going off as I was driving along, which set me to thinking that maybe they were right. This morning I plugged my ODBII reader in and found no error codes.

Then the boot opened itself... This is when a thought started to occur to me like a wave rolling in at the beach.

I have recently replaced my key body with a new one as the buttons had disintegrated on the old one. At the time I did think the new buttons were a bit of a tight fit to the internal micro-switches, but thought nothing more as the rest of the key fitted together quite nicely. So I took the new key inside the house and tried my spare key. Lo and behold the problem went away.

So I think I need to modify the new key body buttons to make them less of a tight fit.

Such a simple thing. I've tried the car a few times with the spare key and it's been fine, so hopefully that's it fixed.

Thanks for the input on the problem, there is some great knowledge on these forums. Sorry if I led you on a bit of a merry dance due to my own incompetence...

[bigwheel]

Don't knock yourself, this is excellent news/info for the "Knowledge Base".

[ARAF]

skoff said:

Sorry if I led you on a bit of a merry dance due to my own incompetence...

Not at all. There's a very long line of people that have 'fixed' something on their car which has caused problems elsewhere. It underlines the importance of remembering what you have done, prior to a car playing up.