So bought a wrx off here from a seller, he replaced o2 sensor cause it was missing (turns out this has f all to do with the miss), i then had to replace the coil packs etc cause thats what caused the miss (was not happpy). Car goes a LOT better now, but, when i put my foot into it and it comes on boost, it goes over about 3000 rpm and goes booooooooooost psh booooooost psh, all the way through the rev range.
Any ideas anyone! Getting real annoyed car was vtnz checked and everything, they didnt pick up shit, it also has leak in the rocker cover and the main seal, also not picked up by VTNZ, moral of the story, DONT USE VTNZ!
VTNZ is not your local garage, not their perogative to pick up faults, only if they cause safety issues. Take into a shop and get it looked over (not just the issue at hand but a full check as well, never know what else could be wrong with it). SOunds like you picked up a thrashed and trashed car, ouch.
supernova2,
Aug 3, 10:19pm
Was the VTNZ check a WOF check or a prepurchase check!If a prepurchase go back and make VTNZ pay for the repairs.
jas_nz,
Aug 3, 10:46pm
check spark plugs and ignition leads
hijacka,
Aug 3, 10:59pm
Allnear 20 year old Subaru's leak oil in those places unless they have been fixed. It sounds like the miss was partly coursed by coilpack or 2 being split. Which also tells me that the subaru is pre 96.(coil on plug) Your problem will probably be simple! Start with plug type makesure your running ngk pfr's if not then change to this plug. next is close the gap to around .6 as when its coming on to boost could be blowing out the spark i run .6 gap on mine as passed 18psi it was blowing it out. Next and probably the real culprit is your fuel pump worn out. This cause cut out more evident at high rpm and open throttle. get it fixed asap as drop in fuel pressure can cuase it to lean. Bang a $100 walbro pump in it and stop your whining!
unbeatabull,
Aug 4, 12:27am
Check all your turbo hoses etc. Had a similar problem when on one when the hose clamp on the Hose to the intercooler was loose and boost was leaking out.
extrayda,
Aug 4, 12:57am
Faulty / wrongly adjusted BOV!
pc_evo,
Aug 4, 3:34am
All good replies, bar the ones about VTNZ, in reply to those, when you pay for a comprehensive vehicle check, you expect one, you would expect them to pick up oil leakin onto the exhaust manifold from the rocker cover gasket, IF they had driven it, ITS OBVIOUS!
In regards to the turbo issue, all coil packs have been replaced, spark plugs are new, its STANDARD AS, boost has not been turned up but not 100% sure how much boost its running cause no guage.
If it was fuel pump, wouldnt that cause the whole car to lag! It doesnt seem to, just the boost hijacka, any more suggestions!
If im going to repalce the fuelpump call me n00b but where does it sit, how hard is it!
Many thanks for all the suggestions, and i have asked on clubsub, but its not proving very helpful.
pc_evo,
Aug 4, 3:38am
Checked all hoses, seem to be tight.
hijacka,
Aug 4, 3:46am
We are all noobs at some stage, The fuel pump sits behind the rh passenger seat remove carpet, First loosen the fuel cap so the tank doesn't pressurize and piss petrol everywhere when you remove the lines. remove cover about 6 Phillips head screw. then remove the fuel lines and plug and undo 8mm nuts (socket and ratchet and remove fuelpump assembly. Not hard just be careful not to damage the rubber lines. give them spin as you pull;) The new walbro 400lph pump is a very good option over the metal geared gss341 walbro aswell
unbeatabull,
Aug 4, 3:48am
Don't do it when ya fuel tank is full either unless you want petrol all through your interior!
hijacka,
Aug 4, 4:19am
Could also be split! Might need a double check
unbeatabull,
Aug 4, 4:24am
Get a can of CRC or BrakeClean or similar product and spray it around all the hoses, manifolds etc. If there's any leaks the engine will miss/stall
hijacka,
Aug 4, 4:58am
I use ether in a can like (start ya bastard), won't make it miss but will increase idle speed if the leak sucks it in, sometimes if there is a tiny leak like a manifold gasket etc may not pick it up as it will only lleak under pressure. Standard Subarus boost at least 14.5 psi factory.depending on tune. there are sti examples that boost 18psi not all are capable of holding max boost pressure to the red line though. any way best bet there is to measure the difference between pre throttle body boost pressure and inlet manifold boost pressure. Its normal to see afew psi drop but anymore than that will almost certainly mean a leak. also the high pitched turbo squeal in top gear at high speed and load can also point towards a leaking manifold. pc_evo does you turbo have a 90' bend or does the induction run under the manifold!
tlharrex,
Aug 4, 6:19am
You haven't put regular 91 octane fuel in it by any chance! My old WRX did a similar thing (by the sounds.) the one time I made that mistake. The only other time it did anything like that it was the air flow meter. Club Sub would be a good place to look for a solution. Check the error codes stored in the ECU, google if you don't know how.
metzeler,
Aug 4, 6:31am
"Of here" so how long ago was this!
pc_evo,
Aug 4, 6:50am
Metzeler, this was Monday last week.
Anyway, much more investigation took place, and, found that some B*stard, has put the air filter box back on and broken the hinge side of it (closest to the motor) so there is now a bit of a hole there. Also, IMO the filter needs replacing.
So the question is this, would that cause my issue! If i change to a POD will that fix the problem ! (i imagine that to be cheaper than trying to find an original air box and the other bits that arent there). Also, since it has the AFM right at the end of the intake pipe, is it hard to install a POD!
NO it has not had 91 octane fuel in it, to my knowledge.
A mate suggested could be BOV not holding pressure enough (broken / worn spring) i dont know enough about them, but that sounds feesible.
bellky,
Aug 4, 10:00pm
Yeah mate that's what it is. Wastegates and BOVs are spring loaded to let off psi at set rates. You've got a BOV or wastegate there that is dumping your psi too early, way too early. I'd say you've got an aftermarket BOV on there that's set too light, way too light.
pc_evo,
Aug 4, 11:01pm
Nah its standard BOV, would boost leak do it too! so either ist F**KED or leaking boost, mate suggested soapy water, spray on all points while engine cold, then start it give it some revs look for bubbles. That work for checking for leaks! Does the turbo boost up as much whne not in gear! (as you can tell im not a mechanic :()
unbeatabull,
Aug 5, 12:11am
No, you need to do it under load. Say in gear with brakes and handbrake on and slowly let the clutch out with revs on.
pc_evo,
Aug 5, 3:59am
checked MAF looked carbonated on one side. cause the problem!
unbeatabull,
Aug 5, 4:00am
Can do. Give it a quick clean and let it dry, don't blow dry etc.
hijacka,
Aug 5, 4:09am
What colour sticker is on the afm!
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