Since I was tuned by Al at Buschur in August, my car has been pouring black smoke at full throttle at every shift, and my bumper is so black that it has yellowed my white paint. It's so bad that a friend of mine called me on our way home and asked "Why is your car pouring out black smoke?"

I also still have the ridiculous chugging of the Buschur cone filter at low boost. I have to either stay out of boost, or go fast enough to hit 9-10 psi or it will will chug.

What are these symptoms of? Poor tune? Not enough boost? Should/can I go back to the stock airbox when I'm tuned using the Buschur cone?

Thanks

 

Obviously at the time you were tuned the a/f was measured on the dyno at between 11.0 - 11.4 / 1

Cars can develop boost leaks which can lead to the a/f going richer

Black smoke can just be due to a poor fuel quality or can also indicate a miss fire

The ONLY way to determine if the car is running a proper a/f is with a wide band O2 sensor

What kind of BOV do you have ? A VTA BOV can lead to rich conditions during shifts

As for your intake I don't know what you mean by the intake chugging

It sounds like compressor surge and a BOV problem ?

Please clarify

AL

 

Stock BOV. Fuel is always Sunoco 93 from the same station and is the same as what it was tuned with. I did not fill up until after I left the tune to make sure of this.

By chugging, I mean the intake starts to suck in the air, then quits, then starts, then quits, etc...all very rapidly. It is fine if I let off the gas or give it more gas, but anything from 0-8 psi it does this - always has.

 

sounds like a fluttering BOV

 

So how do I fix it?

Thanks

 

So what will happen if I go back to the stock air box?

 

It will be less audible, but it will still be there. I would know considering it will do the same thing if I do the same thing about boosting 5psi or so and then letting off. In other words, its normal.

 

So it's supposed to run like crap when trying to drive at normal speeds? That sucks. Why didn't it do it when I was stock?

 

Hopefully someone else can answer because I would like to know as well lol. To avoid it, I either don't get into boost or make sure I reach about 10-15psi and let off so it doesn't make the noise. I think its a minor setback when modding, but the car is so much faster than stock and I don't regret it.

 

It's not running like crap when trying to drive normally. You're inducing compressor surge by partially boosting - the system can't handle that, especially on a strong BOV like your stock one. It has absolutely nothing to do with the intake - not sure what would give you that idea. You have to go full boost or don't boost, and if you are part throttle accelerating, then let off completely with your foot - don't let off the gas slowly or it will cause the car to buck.

As for black smoke pouring out between shifts, if it didn't happen the moment you left the tune, then something has happened. Our cars don't do that in stock form, and they certainly don't do it when tuned. There's no way he tuned you more rich than stock, so it's highly unlikely that it's related to the tune. You need to verify by checking the AFRs and doing a boost leak test. You can't just have a friend tell you there's black smoke then come online and ask us why. We have no clue until you actually check some things and find the source of the problem...

 

You're right Warrtalon, I should KNOW what to check before I ask for ideas on what to check If I knew what the possible causes were, I wouldn't have come online and asked!

Al answered by saying cars can develop a boost leak - GREAT, something I can check, and also told me to check A/F ratios - I don't need smart responses from you. Or any response for that matter...I am not your customer.

 

Sorry, I thought his answers were common sense to anyone who owns and mods an Evo. I must have overestimated you.

 

HAHAHA - his answers WERE...for the black smoke. However, according to you I should have know what to do BEFORE I asked! HAHAHA

 

Clay a/k/a warrtalon is only trying to help you - please read his advice very carefully as it is usually spot on !

 

I don't dispute that one bit! When I first came on here, I read his posts carefully to get an understanding of the car, but I don't need smart-a** comments