98 wrx power loss

dj fbi · Post by **dj fbi** » Mon Nov 29, 2010 3:48 pm

Hi all, I'm having problems with a intermittent power loss and fluctuating revs. When the car losses power it blows black smoke and feels like it has dropped a cylinder. The revs will go all the way down to almost stalling then come back up again. Ive disconnected the air flow sensor and the car seems to run better so far, but wont rev past 3500 rpm without jerking. Ive ordered another air flow sensor. I have replaced the coil and leads, idle control valve cleaned, fuel pressure test. The car is stock apart from a 3 inch for the back cat. Have also tried resetting the ecu. Is it safe to drive the car without the air flow sensor connected until the other one arrives? Thanks in advance

I also got codes 24 and 33, replaced speed sensor and and still got the same codes 24 and 33..

d_generate · Post by **d_generate** » Mon Nov 29, 2010 7:24 pm

Code 24 is IACV I think, have you bought some contact cleaner and cleaned the AFM, also check the plug itself, check all vacuum hoses, another thing to try is plug it back in and try to get the car to idle then wriggle all plugs to see if something happens.
Take it very easy when driving and it should be ok for a short distance.

Post by **TOONGA** » Mon Nov 29, 2010 11:02 pm

error codes are here

showthread.php?t=14372

as well more info can be found here

http://www.scoobypedia.co.uk/index.php/ ... ngECUCodes

and here

http://www.troublecodes.net/Subaru/

TOONGA

RSR 555 · Post by **RSR 555** » Tue Nov 30, 2010 8:55 am

Sounds like shit on the airflow meter.. do you have (or had) an aftermarket filter on the car?

dj fbi · Post by **dj fbi** » Thu Dec 02, 2010 6:31 pm

Ok still having problems, i just bought a new air flow meter reset the ecu and took it for a drive drove fine and hard for about five minutes and then the same problem blowing black smoke no power drives like it's driving on 3 cylinders. I pulled over unplugged the maf started it up no black smoke no hesitation and drove fine below 4000 rpms but does not have any power over that and definitely does not have the pull like when the maf is pluged in but iam assuming that it is some sort of safe mode when the maf is not pluged in?.
This is what has been done
new maf
new coil and leads
new Vehicle speed sensor
cleaned Air control valve
it was showing codes 24 and 33.

littlewhiteute · Post by **littlewhiteute** » Thu Dec 02, 2010 7:00 pm

Have you pulled the spark plugs?

"feels like it has dropped a cylinder" - Is it a misfire, or low power?

I chased a misfire for 1000km until I traced it to a 1300km old spark plug, the misfire started when my new plugs were 300km old.

I have seen many spark plugs faulty out of the box.

dj fbi · Post by **dj fbi** » Thu Dec 02, 2010 7:09 pm

Very low power the more i put my foot down it jerks and stumbles and hesitates? but some times it drives fine.
cheers,
lee

littlewhiteute · Post by **littlewhiteute** » Fri Dec 03, 2010 5:05 pm

dj fbi wrote:Very low power the more i put my foot down it jerks and stumbles and hesitates? but some times it drives fine.
cheers,
lee

Lee, have you run a fuel pressure test gauge on your windscreen on a roadtest?

ORX-18 · Post by **ORX-18** » Fri Dec 10, 2010 6:27 pm

look at the fundamentals.

O2 sensors, blocked cat converter, fuel pressure reg, AFM, WIRING HARNESS!!(they go brittle and crack over the years and cause earthing issues), Spark Plugs, Coils, Heads, CAS's, Knock sensors and then you start to get into the ''Hard'' side of it.

Good luck

drof351 · Post by **drof351** » Fri Dec 10, 2010 10:29 pm

G'day, could it be intermittantly over boosting? Broken wastegate line?, or those factory solenoids that control the boost?