Forester S Turbo stuttering under accelleration

[scoobforester]

Slight problem with my W reg 2000 Forester S turbo manual / petrol.

Occasionally not always but under acceleration it stutters almost like a misfire.

Changed air filter , fitted K & N Panel filter , tightened up all hose connectors and cleaned electrical connectors.

Car will run fine then out the blue stutter for a minute then clear and run for day or two no problem

Returning good mpg around 28 mpg / starts straight away / no smoke from exhaust / idles fine without rev counter moving and generally does what i ask of it. Not using any oil nor water / just done 300 mile trip ok.

Baffled though by this stutter.

Instinct says fuel starvation but its had a walbro pump fitted just before i got it.

Any suggestions appreciated ?

 

[stants]

Have you checked the plugs recently? The rears can be a pain to change so sometimes get left

[Rick 2014]

What colour is it lol.

[Rick 2014]

Does the car missfire under load

[scoobforester]

colour silver ?

does misfire under load

plugs were changed few weeks back

[Rick 2014]

If you have done the plugs then do the leads it is common for them to go.It happened to my forester late last year

[stants]

You running vpower or standard super market petrol ?

[scoobforester]

v power and nothing under 97 all the time

yesterday used that Shell nitro

[Rick 2014]

I always use Tesco momentum 99

[Mr B]

Tesco momentum 99 is good :-)

Check ecu fault codes out of interest, being a W(99) & if this a UK car you have a chance of possibly using OBD cable as yours could have the OBD2 style plug which actually wired for ssm2 & that works with ISO9141 KKL OBD cable & freeSSM software

 

Leads would be good to inspect or replace & not overly expensive.

When you say happens under load, would it be always under reasonable amount of boost ! resistance is higher due to pressure & spark blow out can occur under boost if ignition parts not up to scratch.

Lots of other possibilities, knock sensors quite common but more diagnosis needed really ...

[scoobforester]

thanks / going to have another visual check / inspection before proceeding

[scoobforester]

spoke to last owner who said it occured very rare but thought it was plugs so got garage to change leads and plugs together

 i have full service history so been looked after in its life

odd fault because it runs so well and ive been on two long trips to get it really warm and performs well

the fault is intermittent and not full on every day

going to check all electrical connections in case a loose connection

[extegra]

hey man,

sorry to bump this age-old post,but did you ever figure out what it was?

i'm having the exact same problem on a '06 2.0 N.A