Hi,

I would be grateful of some advice. I have a 2001 bugeye wrx; there is 100k on the clock. It's been not a bother since I got it at 90k but has just developed a misfire. If accelerated hard it goes smooth up until 5k then starts to misfire. I haven't pushed it past this point for fear of damage. Normally ran on super unleaded, but the last half tank was cheap stuff as caught short at the supermarket It is due it's service; was assured the timing belts were done at 80k. The only mod that was present when bought was a BOV (not to my taste, but wasn't a deal breaker ) Any ideas of what the prob it could be?

Thanks!

 

i had a silmiler problem of misfire in high revs, ended up bein the ecu needing a new firmware!

 

have you checked the plugs, leads etc?

 

yep if due a service new plugs, and check coil packs, if they have a fracture they can open on high load

 

Is it just a misfire or could it be fuel cut? You can pull through a misfire but fuel cut is just that, ecu cuts fuel because it has noticed a problem aka limp mode.

If it is limp mode then a read of the fault codes will steer you in the right direction.

 

Do be carefull untill you get to the bottom of this, my car developped a machine gun missfire at higher rpm on the weekend on track. I pulled over the following lap to find a massive det reading and and a rattly noise when reved a bit and at idle. I got about 8 miles up the road before sitting in a low loader for next 100miles with a destroyed bottom end :-( I only worry cause you say you stuck some regular fuel in it and while the above comments are sensible, it still means testing it by running up to 5000rpm+ Certainly get some octane booster in it and if you are really worrried could be an iea to get it on a dyno and have AFR checked and det cans on it.

don't want to scare you mate, all the best and let us know how you get on!

regards
Ash

 

Check your ht leads and plugs

 

Thanks for the replies, some good stuff to look into. First thing I did was get a full tank of vpower into it and I'm going to sort out the parts for a good service, what spark plugs, oil etc would you recomend? I'm not sure if it's feul being cut or mis-fire as I have not tried to force through it; if sorting the basics out eg sevice, leads; and if that does not help will have to look deeper

 

i had this EXACT problem. ran fine with V-Power, then when using other fuels it started mis-firing and kind of hesitating at around 5-6k rpm.

then, after a while, it started doing it with V-power too.

turns out that the gap on the spark plugs was wayyy too big.

replaced the plugs, reset the ECU, not had a problem since.

this is definitely your first port of call. get this done, reset the ecu, and you should be golden again!! make sure you get the right gap on the spark plugs with the new ones too!!!

 

Hi,

I had something similar last year. I thought the car was beginning to Det at higher rpm as the knock sensor (Apexi) picked it up before you could feel it - if you pushed on it became fairly obvious from a driver, rather than sensor, perspective.

I did the usual Plugs and HT leads and it didn't help. It turned out to be the Crank Position Sensor. This was failing and caused the car to think it was at higher rpm than it was for a fraction of a second every now and again - always when going over 5k rpm under load though. Basically, when the car thought it'd exceeded 7k rpm (we actually saw a spike of 11k indicated on a mapping run via the diag tools lol) the cars rev limiter kicked in, introducing a miss-fire that the sensors saw as knock. After replacing the sensor all was fine.

It was just starting to fail hence the very intermittant nature of the fault. It was a fairly expensive item - over £100 I think - so not necessarily the first thing to try. However it is something to bear in mind if doing the other, cheaper options proves fruitless.

Cheers,

G.

 

Sounds like I should start with the spark plugs etc, service due anyways. What type is best for 2001 wrx?

 

check your plug gaps i had the same problem re-gapped the plugs and now sorted

 

Thanks for the advice, I'll start with the sparks then, fingers crossed! I'll let you know how I get on!

 

Yesterday the car would not rev above 5k and felt flat

Today I've put new sparks in all round; the're are sods to fit! Checked the gap on the out going ones and it was 0.9mm and made sure the new ones were 0.7mm. Stuck a k&n panel filter in while I was at it. The car will still not rev past 5k rpm; do you think it is stuck in limp mode? Not had a chance to check for any error codes (hopefully will do tomorrow).

 

Have u reset the ECU? Disconnect the battery, and leave it over night if you can. This will allow the ecu to completely reset. Then reconnect the battery. Worked for me

 

Thanks! I'll pop out and disconnect it now - fingers crossed!

 

Well, no joy with the disconnected battery

Have plugged into the ecu and have found the following codes:

P0301 - drivetrain mis-fire
P0302 - drivetrain mis-fire
P0303 - drivetrain mis-fire
P0304 - drivetrain mis-fire

Cleared the codes and still popping. Using torque pro app which I don't think can fully reset the ecu? Any suggestions are welcomed

 

Neutral position switch would be my guess. But could be an induction leak

 

But that didn't show up in the fault codes!

I'd look through the ignition circuit. You have changed the plugs, now check leads, coil, and the low tension circuit to the coils. As there is a misfire at all 4 plugs I'd guess that it is not the leads but something before that.

Reset the codes. Drive it. Then read the codes again just to to double check.

 

Think nps throws up missfire on 4 code ?

 

The codes are on all four cylinders. Unless there are two separate problems.

 

The nps often will throw missfire code for all 4 cylinders and no code for the nps itself.

 

OP. Check everything mentioned and post back.

 

managed to get a good run out today to see what errors are thrown. This time three cylinders came up as misfire and this one as well:

P0546 - high exhaust gas temp

The car is running standard boost etc, could this be a knackered cat in the up pipe? That could explain the lack of boost and misfires?

 

bttt

 

Any luck yet?

Is there any way of testing a cat?

Where are all the tuners gone on this thread? Surely one of them have seen problems like this before?

 

It's at the Subaru garage now, the mechanic listened to the engine and said it sounded like it was sucking in air. Not heard anything for a day, this could be costly :0(

 

176000 on the clock no mods at all stock standard i have done spark plugs and 2 2nd hand coil packs and under load it makes this cracking sound in the motor then in the next gear it will only run half boost a simple key on and off would fix the problem intill i full boost again but now it is stuck in half boost. car revs right out in half boost with no cutting but is just slow and flat.. i fear the suby guys r going to charge me an arm and a leg for something they cant figure out.. it throws no codes i have paid for a computer to check it over and it all said was the maf sensor was 26 degrees but was only 18 out side.. i mite just add once i changed the plugs it went really good for half a day then crack in the engine and im half boosting again.. i run 95 octane from caltex in NZ sometimes 98 but doesnt help.. coil pack wires are good no cracks.. i wonder if a heat problem would do this. on a cold night like 6 degrees out side it runs like a champ

 

Hi lads need help got my ra back on the road this week and now running it in all runs sweet as up to 5000 rpm but if you put ya foot right down it misfires but if you back off and increase power slowly it is fine. The cat is for its mot new fuel pump and filter the only thing that ant standard is the air filter witch is his. The car run fine last year with it all on and it had the decay on as well. I am lost now lol just rest the ecu and the engine check light is blinking as it should. Any ideas plz

 

Hello from the past, lots has changed here. 😀

Sounds like an over boost issue to me. Could also be coils and/or plugs, a split boost hose, boost solenoid etc