Poor initial cold starting

[Judd]

2008 XT 2.5.   Only just over 50k miles from new.

Last few weeks our Forester has not started instantly from cold, turns 2 or 3 seconds then fires up, then its fine.   Once initially started it'll start happily all day long.   Prior to this it was an instant starter whatever the weather.

Runs perfectly otherwise.  Battery is perfect, full spec 5 year warranty Yuasa 2 years old at most, no signs of Battery failure, voltages good, it turns over healthily enough.

It's as if there's a fuel pre pump which isn't pre pressurising the fuel system, since this has been happening i've listened out for the sound of a fuel pump prior to starting, can't hear one but then for the 4 years or so we've had the car can't say as i've noticed the sound of a pre pump anyway.

Any suggestions please  or is it a case of letting my indy have it overnight so they can check the system from cold, its in for MOT in a couple of weeks so an ideal time to do the diagnostics if necessary.

[Judd]

Well it went into the indy overnight, yup you guessed it, started first time next morning, they arn't a Subaru specialist so didn't seem keen to get involved.

Anyway, things progressed up to my week off this week and on Sunday i swapped out the fuel pump, Mon and Tues it started instantly and the car seems to run better but that could be wishful thinking, however still spluttering for a moment on the cold start.

So, today i've picked up 4 new spark plugs and have swapped the two offside ones out, bit fiddly but not too bad, i've swapped H6 ones out before, worse job, so i thought, now i've removed the Battery and am dreading changing the NS pair tomorrow, the whole wiring loom is right in the way and the connections arn't playing ball.

Haven't raised the engine yet so might undo the engine mounts and jack it up a couple of inches to give a bit better access.

Had to undo the engine undercover anyway because i must have dropped either the extension, ratchet or plug spanner 30 times if i did it once.

Wish me luck for the morrow chaps, i'm here feeling the half dozen fresh cuts on my hands stinging, so should make the full dozen by the time the job's done.

[Judd]

All sorted, running sweet from a now instant cold start.

Never again do i want to change a set of spark plugs on one of these, cuts and abrasions on hands and wrists total  17.

[Tidgy]

Glad you got it sorted, haha yeah they are a ball ache to do, i've never done mine myself haha

[Brack]

Mine is hard to start in very hot weather so the opposite to yours really. It will only start up with a squirt of the accellerator (automatic box).

Pleased you got yours sorted Judd. 

[Judd]

Interesting Brack.

I've refined my starting procedures and things are working consistently well, the secret seems to be to turn the ignition on, then leave it (as one would a Diesel allowing the glow plugs to warm up) for about 10 seconds or so whilst you sort your stuff out, then start up..incidentally i too find giving it a little throttle helps it to fire up straight away.

Might be interesting doing the above, ie leaving it a few seconds with the ignition on before attempting to start and see if that helps yours.

[Brack]

On 10/4/2023 at 5:45 PM, Judd said:

Interesting Brack.

I've refined my starting procedures and things are working consistently well, the secret seems to be to turn the ignition on, then leave it (as one would a Diesel allowing the glow plugs to warm up) for about 10 seconds or so whilst you sort your stuff out, then start up..incidentally i too find giving it a little throttle helps it to fire up straight away.

Might be interesting doing the above, ie leaving it a few seconds with the ignition on before attempting to start and see if that helps yours.

Thanks Judd, that sounds like a good plan to try out.

It's the only problem I have and only then in heatwave type temperatures - almost seems as though the fuel has evaporated from the injector lines...the only way I can describe it really.  

Cheers