Please help

[slidman]

Hey I have 07 impreza wrx tr with custom IHI VF 48 turbo 42000 miles, I have a misfire on cylinder 1 and 3 sometimes car runs normally but most of the time rpm's a jumping from almost a 300 to 1500 when I'm on the street lights stopped and when driving steady around 2500 rpm's i feel like engine is not working smooth its kinda like dropping rpm's and again run normally ,i checked cylinder 1 spark plug and its ngk and good condition but look like black burned and i think it should be kinda brownish what might be the cause lately I have installed long ram cold air intake but that should not be the problem ?

[GHOST__STI]

Honestly no one on here is gonna be able to actually diagnose your car from a forum, but I just know you gotta be tuned on that VF48, that being said you need to talk to your tuner and see if he cant get some logs on that thing, and if you did it yourself you need to go have a pro tuner look at it. There are a number of things that can be happening rite now and every one and their mom is gonna tell you what they "think" it is.

- if you put the intake on after the tune, its the intake 9 times outta 10.

- if you threw on injectors with out proper tuning its that.

- if you dont have a tune at all ( I think your dumb) its that lol.

- if non of those apply I would have a tuner or your self log the car then have a pro look at it for any red flags.
usually the ecu tells all.
:lick:

[slidman]

There is not a problem with the turbo cuz Ive bought this car 3 month ago and everything was fine it was tuned by spt the problem started maybe 2 weeks ago im not sure if im not running to rich mixture but why?

[GHOST__STI]

have you done any thing to it in the last two weeks at all?

[GHOST__STI]

I would still log the car though, its a good idea to see what the ecu is seeing.

[RS MN]

- if you put the intake on after the tune, its the intake 9 times outta 10.


^this.

also, is your maf clean and plugged in?
do you have a vacuum leak, or an unplugged hose?

good luck!

[slidman]

nop i didn't do nothing to it and I did check the ecu engine light in its showing cylinder 1 cylinder 3 misfire that's all

[slidman]

and when on higher rpm's everything is fine like over 3500

[RS MN]

check if your maf is clean, otherwise, im no help to ya.
i dont know much about FI subie troubleshooting.

[wolfman79]

Check your coil packs and/or the wiring on that side, since it sounds like you have one bank missing. Also do a compression check. Almost all problems, mechanical or electrical, "feel" like they disappear at higher RPM, they don't.

What shop were you tuned at and who did the tuning? And did you have the car tuned or are you just going off what the seller told you?

Oh and ditch the CAI unless you have a good reason to need it. The stock airbox works just fine even at high power levels, trust me I know. I just went through the entire motor in my wagon and one of the few items that I left unchanged was the airbox.

[slidman]

OK I'll double check everything tomorrow ,and I've bought this car already tuned the only things that I installed where intake and bov but like I said problem started long after ,so if I'm not gonna come up with nothing I'm gonna take it to the dealer to check on it

[RS MN]

if you didnt get it tuned after installing the intake, then that can cause problems,
and BOV's seem to cause problems in general sometimes, but it kinda varies from car to car.

also, i wouldnt trust the previous owner if he said it got tuned, i wouldve immediately gotten it tuned afterwards.

[wolfman79]

How long after could it have been if you've only had the car for 3 months? Your MAF sensor does not like the CAI and as a result your AFR's are all FUBAR'ed, and while the BOV isn't the worst thing in the world it too will cause your car to run rich.

Get it tuned ASAP or swap your intake and BOV back to stock.

The dealership is only going to cost you an arm and a leg. They won't warranty it with those mods done. Find a good independent shop and save yourself a couple of bucks.

[slidman]

Damn dude one of my friends who is a pro mechanic after I install the bov he told me that this things couse damage to catalic conv. and he had 05 legacy before as he give me the exedy flywheel and clutch plate with 8k mile on it cuz he toked out before he sold it tho maybe thats the problem the bov after a time make its demage but in other hand ppl have bov with no problems ?

[RS MN]

its not just the BOV, the intake is causing problems too.

[wolfman79]

Bolt on parts do not damage your car/motor. Intakes, BOV', exhausts, intercoolers, injectors, turbos, none of those will physically damage your car. What does damage your car and ultimately makes your motor go BOOM is if you don't tune the ECU for those parts. Your car is not tuned, it needs to be tuned badly. At this point I think you should change your spark plugs, get a compression check done while changing your plugs and take it to get tuned.

I don't know where in IL you are but try to get a hold of the guys over at P & L. They'll take care of you and your car.

[slidman]

I think Im convinced tomorrow ill put the stock intake box and Ill throw out the bov and Ill see what will happen trough the weekend!!!

[slidman]

Thanks for help guys!

[wolfman79]

You still need to change plugs, do compression check, and get it tuned.

[GHOST__STI]

Just to add alittle more to the fire here, I had a custom tune done with my car in august ok, I had a stock intake. about a month later I put a cobb intake in there. about 2 months later I started getting little hints here and there that my car wasnt running right ( same stuff you are seeing now) I ignored it alittle, retard the timing a bit. but kept driving. two weeks after that i pop a few codes. I read then reset em, took off the intake I had no tune for. and i never had a problem since.

I dont have a tune for your intake, that could very well be your problem, many people make this mistake. Even if it didnt cause this problem you are having now, I would suggest getting your car retuned if you plan on keeping that intake on. just my .02

[kemikalembalance]

I can solve your problem!!!

I still kinda new here but I found alota good info from this forum. But Ghost is right, no one is gonna fix those probs here. Find a very reputable tuner or take it to the dealer.(uugghhh...dealers:unamused:). The guy that tuned my car said the biggest problem with modded subees running poor after upgrades is some tuners or sales shops treat them like hondas. These computer systems are alot more picky than that. They dont adapt to part changes like others do. And with the turbo, you can melt your engine very quickly.
Stop driving it till the prob is fixed. You might do some perm damage.

[pigpen]

can you get the dyno sheets from the tune? was it done by someone familiar with tuning subies? if not, you might need a tune even after pulling off the new parts you put on. with a VF48, I'm pretty sure you don't need a BOV...the stock BPV should be fine.

do you know where the RPMs are when you are misfiring? that will let you know how much damage you might be causing driving around as well as help point to different problems. if the misfires are only at low RPMs, they shouldn't really be causing any damage, and the problem is typically the injectors having trouble with low duty cycle performance (partial internal short or mechanically sticky).

[rollo]

Find a very reputable tuner or take it to the dealer.(uugghhh...dealers:unamused:).

I wouldn't take it to a dealer. Dealer techs are trained to fix stock cars. You might get lucky and find one who's enthusiastic and knowledgeable enough to diagnose. But even then there's no reason they'd have the tools to do a custom tune as far as I know.

[pigpen]

I wouldn't take it to a dealer. Dealer techs are trained to fix stock cars. You might get lucky and find one who's enthusiastic and knowledgeable enough to diagnose. But even then there's no reason they'd have the tools to do a custom tune as far as I know.

yeah, definitely wouldn't go to a dealer for this problem. if they even agree to work on it, they will likely charge you a lot for diagnosing the problem, and you'll probably end up leaving with very little new information. there are only a very small handful of Subaru dealers that will tune away from stock, and the one I know locally is more of an install shop that I would expect are more inexperienced when it come to diagnosing problems (I think the only tuning they do is OTS maps in the Cobb mated with parts that work reasonably well with that tune).

[slidman]

I have put the stock bpv back, car runs little more powerful but its a minor change the think is that car runs fine, only when idle sometimes I got misfire, or runs normal, and when i shut the engine of and start it again ,right after start, it shake like mofo,when I step on the gas it stops, and runs normal or shake again when idle, but this happen only when engine is hot when I start it when cold runs normal maybe spark plugs have some temperature prob.

[slidman]

Im goin to the car wash , and gonna get new spark plugs ,replace them and see what will happen! thanks guys

[slidman]

OK I did bought a new NGK iridium spark plugs ,and its worse than it was. Right now I have big misfire at high rpm's including the one with idle that I've had, when I step on in there is a moment that I can feel it, that engine stall for half second at around 4000 to 5000 rpm's **** I think I'll go to performance shop first and if anything I'll go to the dealer tomorrow !

[wolfman79]

Which shop are you going to? Be very picky about this, make sure you find a quality shop that has experience working with Subarus. Save the dealer trip as a last resort kind of thing.

And did you get rid of the CAI yet?

[snaggleto0th]

it almost sounds like its running too lean with the new intake but not enough to set a code. Your intake is probably causing the issues. The 32bit ECUs are way more sensitive than the 16bit ECUs. Put your stock intake on or take it to your tuner to get tuned for the intake. If you changed your plugs and it got worse it tells me that your running too lean cause now you have a better spark. What intake did you put on? But defantly see a tuner that knows subarus for sure!

[slidman]

Heh I was at the dealer ,spend 3 hrs pay 80 bux and everything is fine for them what a bs

[CO_AWD]

Sometimes you even need to get a tune for the BOV so that your engine can compensate for the loss in pressure. You can't just toss aftermarket parts on and drive away.

[02wrxRally]

I would suggest talking to George at P & L. I've talked to a lot of people in chicago about where to go to get tuned and he's been at the top of the list for recommendations. He seems to have the most experience AND good results from what I've gathered. Mike, the salesman at Evanston Subaru who's on MWSOC, suggested them too.

[slidman]

Yeah I've talke to guy at P&L And GRD and both of them told me to put all the old stock junk back so I did it and its all good now, next time Im gonna go to one of these places to tune my ecu for all the staff that I wonna put into damn these new cars have to much of electronics in them I hate that .