DC5 over fueling, possibly Bore Washing?

[Chris_EK4]

After some advice, my DC5 has started chucking out black smoke (varying amounts) to the point where its staining the rear bumper (takes a few days of heavy booting/driving, washes off though with a bit of a scrub) it has a decat dc-sports manifold (engine light never came on!?) and a 3'' solid fab cat back, It smells quite strongly of petrol when you take the oil cap off and smell, not overwhelmingly but definitely smells of petrol, I think it was always running rich to an extent but maybe the exhaust has worsened it? scared it may be bore washing? does it sound like likely bore wash? It spits small flames now and then when racing it.

It still pulls strong, Can't get 1st gear traction at tall even in the dry under heavy acceleration so hopefully the engine is still internally strong just want to ovoid damaging it. It doesn't seem to be using much/very little oil and no blue smoke that I can notice. All though when it was completely standard The quickest 1/4 time I could get from it was a 15 dead, so maybe its a tad weak, though it was on a boiling summer day, and was my first time on the strip and only owned it 4 days at the time, just expected a bit better from it, (around 4-5 months ago) so just concerned it may be a long standing issue from the previous owner too...got an 70mm rbc/70mm tb and getting it mapped in march, so thinking it may solve the issue with a custom map?

Thanks for any advice

 

[Crazylegs]

I'm no mechanic but I'd have thought the overfuelling would be because of the changes to the exhaust and the 70mm inlet. I'd get it mapped now rather than March as there may be a risk to your engine driving around hammering it in VTEC if it's running too rich or too lean.

Someone with more knowledge than me will come along I'm sure.

 

[beppe786]

Smell dip stick if you smell fuel its definitely overfueling.. plus when its more torquey means overfueling doesnt mean its quicker just pulls better

Faulty injecor could cause it.. or 02 sensor reading leaner as on way out

 

[C&S Evo7]

my advice would be to get it mapped NOW. or risk permanent damage, petrol in the oil is really bad.

the rbc and exhaust change the air flow requirements of the engine considerably, the lambda sensor is trying hard to compensate but it cant as its way outside its operating range so i expect has just switched to open loop and is bucketing the fuel in,

 

[Chris_EK4]

thanks for advice, Sorry I wasn't clear the RBC isn't fitted yet, just the Headers and exhaust, although I found out the headers are blowing (flexi crack) so might explain lack of engine light as crack is before second sensor, the dipstick doesn't smell of petrol just the cap, strongly though, so there's defiantly oil in petrol I'm assuming?

It stains the exhaust tip in a day or two (BLACK) how long would it take to do damage to the engine I stopped using the car as soon as I was aware of this but it could have been doing it before

 

[C&S Evo7]

so, have you got kpro already fitted?

it shouldnt be anything like that rich unless its poorly