System too rich / Possible overboost?

orion3 · 07-16-2008, 12:22 AM

Hi, i posted about a month ago trying to figure out what was wrong with a 2004 wrx i puchased. Since then its been in numerous shops and i still cant seem to get it running right. The first major issue was a serious missfire and complete power loss. After a compression test it was determined one of the cylinders had bad compression. A mechanic fixed an intake valve and the compression was restored. Now the car is running much better, but still not really driveable. The car was running extremely rich with black smoke almost constantly out the exhaust pipe. I took the car to a tuner to see if the ecu had been flashed. The map was really out of wack but the tunner attempted to tune it as correctly as possible. Today i came to pick up the car and the tuner explained to me that the car is running but only at about 3000 rpm's or lower. He suggested i take it to a subaru dealer and get the stock map flashed. I drove the car today and it basicly runs fine until I start reving to 3000 and the car starts boosting at this point there is an immediate power loss. Also at times when im not even on boost it will start to loose power become sluggish and jerky, at this point there is black smoke coming out of the exhaust a symptom of being rich. I believe i have two problems. I think the car is overboosting due to a malfunctioning 3-port BCS that is installed. i would like to troubleshoot this but i dont have a stock one to swap it with. I also think i have either a boost leak or just a very poorly tuned ecu. The only CEL i am getting is SYSTEM TOO RICH. Whats strange is the car seems to randomly begin running rich and then return to normal while im driving.

Any tips would be greatly apreciated. Thanks

nagyhead · 07-16-2008, 01:02 AM

what injectors, turbo, or fuel pump do you have?

Longshot · 07-16-2008, 08:25 AM

Have you checked all the vacuum hoses? Especially around the solenoid? You could check on nasioc for a stock bcs which should be really inexpensive. Do you have any form of EM at all? You could correct the map yourself with a laptop and tactrix cable.

nagyhead · 07-16-2008, 09:33 AM

pm me if you want a factory BCS, I have 3 or 4 of them in my garage.

orion3 · 07-16-2008, 04:53 PM

I know the turbo is stock, but I am not sure about the fuel pump and injectors. I know i would have to open up the gas tank to get to the fuel pump, but is there a simple way of determining if the injectors are stock?

As of right now I have no kind of EM, is that tactrix cable something i can purchase locally or would i have to order it?

All of the vacuum hoses have been checked, I even completely removed the BCS and re-installed it following directions from NASIOC and its still running rich

Longshot · 07-16-2008, 07:45 PM

youd have to order it from tactrix.com. The opensource thread on this site for some guidance if you go that route.

dumdum · 07-17-2008, 06:25 PM

Quote:

Originally Posted by orion3

The map was really out of wack but the tunner attempted to tune it as correctly as possible. Today i came to pick up the car and the tuner explained to me that the car is running but only at about 3000 rpm's or lower. He suggested i take it to a subaru dealer and get the stock map flashed.

What em are you using and why couldn't your tuner do this?List all your mods again.This is why you don't by a modded car.

orion3 · 07-17-2008, 09:03 PM

Trust me i wanted a stock car, but i came across a good deal and i went for it.
I was able to speak with the previous owner of the car. Turns out the car has the 2.5 shortblock swap, 740cc injectors, and a walboro fuel pump. I obviously need to tune the fuel management to account for these injectors. What i dont understand is why the injectors are so massive. Is there even a reasonable way to tune this car to run properly with such massive injectors? Keep in mind it has a stock turbo. And will i ever get reasonable gas mileage? Im sure if the tuner was aware of these modifications they could have been able to get it running much better.

Longshot · 07-18-2008, 07:57 AM

I'd say get a bigger turbo and protune, you're almost there. Slap on an 18G. That or get rid of the injectors/pump and find stock stuff to put in.

nagyhead · 07-18-2008, 10:40 AM

^^ word
I have 820 cc injectors and my car dosent run rich. you will need to find another tuner if he cant tune your car. did he know it was a 2.5 with 740 injectors? Because i bet if he did he would be able to tune it.

dumdum · 07-18-2008, 06:05 PM

Quote:

Originally Posted by orion3

Trust me i wanted a stock car, but i came across a good deal and i went for it.
I was able to speak with the previous owner of the car. Turns out the car has the 2.5 shortblock swap, 740cc injectors, and a walboro fuel pump. I obviously need to tune the fuel management to account for these injectors. What i dont understand is why the injectors are so massive. Is there even a reasonable way to tune this car to run properly with such massive injectors? Keep in mind it has a stock turbo. And will i ever get reasonable gas mileage? Im sure if the tuner was aware of these modifications they could have been able to get it running much better.

It is incredibly easy to tune for larger injectors.The original owner probably had a bigger turbo and sold it.Take it bake to your tuner.