ok people just took my subaru wrx jdm turbo my95 out again after checking boost pipes ect. now when you start your car should the boost needle on the boost gauge read 0 as when my car is running the boost gauge actually goes into the minus not sure if this is normal as i thought it should be sat at 0 bar not in the minus.. also when i boot it the car pulls but all of a sudden when the boost starts building up the car just starts back fireing,holding back and the boost gauge needle goes mad flying up and down..the car was working fine until last week when this started to happen i have not changed anything for this to cause the problems so any advice would be much appriciated kind regards ben

 

when the car is idling it should read about -0.8 bar and it sounds like the fuel cut is coming in or your suffering a bad misfire mate

 

Have you changed the plugs or oil or had a service in the last year or so

It's a mapped/modded motor is it not? Then it need regular maintainance

 

it has had a service about 2 months ago plugs about 8 months i did top the oil up at the weekend.the car has simtek ecu,fmic,straight throught 3" exhaust.vf35 turbo,and a few other bits the car was fine last week it has just started. when i first bought the car around 2 years ago it was running at 1.3 bar and running fine but after about a year it dropped down to 0.8 i just ignored it then last week my mate found a little hole in a pipe so we change it and then i had full boost again 1.3 bar but last week this happened...i think the boost gauge reads aropund 0.8ish ill have to check again

 

You didn't over fill the oil last week did you?? That can cause all sorts of problems, should be upto the top hole, not the top 'v' mark, just another idea for ya[/COLOR]

 

a may have over filled it slightly i will check tomoz. I'm sure the problem started just b4 i changed the oil,i did take the plugs out 2day and clean them with wire brush but it doesn't seem 2 have made much difference

 

coil packs?

 

have you checked your coil packs? mine is boosting funny as in spluttering/juddering when under boost & its down to my coilpacks being knackered. @ £70 each for genuine im driving her nicely untill all changed & buying one every other week, just got my 1st one yesterday!

 

It don't take alot mate, iirc it over flows into the BCS and gunks up the boost control, very sensitive these Scoobs. Do a quick search on overfilled oil or simular Did you check the gaps on the plugs whilst you had them out

 

i checked the coil packs out 2day and couldn't c any cracks in them 2 suggest there on there way out,is there any other way 2 checking them. as 4 oil is it a case of draining some out until gettin 2 the correct level

 

Yeah drain some off then flush the BCS and pipe work with brake n clutch cleaner

 

sorry mate i abit slow what is the BCS,also i've got a spare set of coil packs comin tomoz and also new plugs so will let u know how i get on,cheers 4 the help

 

Sorry mate, BCS, Boost Control Solenoid mounted on drivers side suspension turret.

Are the plugs NGK pfr7's? Gap them to 0.65mm since your running a modded set up.

Best of luck

 

Sounds more like MAF than Coilpack etc... but annoyingly its a process of elimination with ignition/fuelling issues. Mine was a combination of MAF on its way out and a load of sh*t clogging up the fuel filter and fuel lines from running it on the fuel light.

 

i dont belive my car has a maf sensor fitted. as it is running simtek.
i went camping in the car around 2 weeks ago and it was 5mph everwere in the camp and the car really did not like it by the end of the weekend the car was running rough.as it is fuelin a little extra with all the mods. i took it back on the main road after to open it up to try and clean it out by open it up,

 

ok ppl quick update stuck a can of 10k boost through it 2day and also redex in with the petrol it seems 2 have solved most of the problem still got slight boost issues. it is hard 2 explian but when i open the car up on full boost u can feel it holdin back and also seems 2 have dropped a little boost,any ideas on what could cause this?