hi had my wrx for a while and had a problem with it cuttin out on hard boost, it was when th very cold weather was here and people said i prob was the cold air? unfortunatlly the weather has got quite a bit warmer and ive still got a prob on hard boost in 3-4-5 gear more in 4-5 gear, ive got no boost control so not shore whats its set at.
the cars info- z4 ecu, race manifold, full 3.5decat, hks filter,hks bov any ideas peeps plz

 

If its an early classic its could be one of your coil packs giving up? Worth checking the plugs too. Does it seem to hunt a bit when idle-ing? you would do well to drop in a boost guage too bud as you'll be able to see if you got any spikes etc. if its overboost youd be peeling your face of the windscreen when it happens. If its like a judder and power loss when pushing it you'll prob find its a coil pack. Whip em out and see if any have crumbled under the rubber neck. Glue them up with araldite temporarily and dont push the car too hard and then order your new ones - X-packones are fairly sturdy.
Hope this helps.

 

coil pks are only 1 1/2yrs old its like u hit a wall then the boost is back, when it first happend i thought i popped it, but boost was back with in secounds, its due for a a oil change now, so ill get new plugs aswell. any ideas what boost gauge to get and where from mate

 

You might find a guage in the for sale bit but Halfords sell them. I got a 2 bar one from there and it works fine. You can find pods on ebay - get the model specific ones though! - Depends where you want the guage and what make if your going the whole hog Defi guages are v nice! if youve got the early motor then you could find a lamcoe triple set theat will go in the centre console.
It sounds like this could be overboost/fuel cut - check for any worn or cracked hoses and run diagnostic check for the boost soleniod - give it a clean and check the lower pipe to it to make sure it has the restrictor pill in it - about an inch or so in from one end.

 

thanks mate but i ant got a clue to be honest to find or how todo what u just said?

 

Check for a thread on here for fault codes/diagnostics etc. There are two sets of connectors under the dash (drivers Side) 2 green and 2 black - they shouldnt be connected at the mo. The black ones are read memory plugs and the green ones are system check. connect the green 2 and this will run a check of the electrically manged systems (fan, boots solenoind etc..) you should here the solenoid clicking away when you connect them (this is mounted on the turbo side front of the suspension top mount).
Run a search for the fault codes and the black connectors will read the fault memory - depending on the sequence the engine chech light flshes will give you the fault code. Good innit!
There are 3 pipes on the boost solenoid the on in the bottom should have a brass pill in it! clean all the pipies out and check the pill is still in the pipe.
There is loads of info about all this on the net bud as I went through all the same stuff as you.
Subaru performance handbook is quite a handy reference too. MRT guys in oz - you can get it downloaded or buy a hard copy. Pop subaruperformancehanbook into google if youre interested.

 

fuel cut from overboost the decat etc has caused this . the only cheep was to fix this is with a MBC they are about 20quid . set it to 1.1bar or 16psi end of problem

 

Or you could adjust the actuator??

Could be as straight forward as that but its well worht checking all the hoses and the solenoid. My decat has caused no overboost at all and the actuator does its job spot on 1.1bar with a heavy foot.

 

The first thing you need to do is , fit a boost gauge! Because at this point in time you have no idea what you are dealing with