Crap out of the exhaust over 4000 rpm

[Hi RX7]

Is it normal to have what seems to be a plume of black exhaust smoke as you pull away at high revs? I have noticed this a couple of times in the rear view when in second gear and accelerating away pretty fast it only appears as a plume when you start to pull away and there does not appear to be any after that, is this just excess carbon being blown out of the engine?

[m1tch]

I guess it could be built up carbon from the exhaust system, I know my FC gets a good carbon coating on its exhaust tips at times. What is the oil consumption like?

[Hi RX7]

Doesn\'t use much at all, that was my first thought that it could be oil but I have recently bought the car and put nothing but V-power petrol in it so I thought it could be just carbon otherwise I would have noticed smoke at other times maybe.

[mpk490p]

rotarys like to be driven hard ever once in a while, have you been driving with care for a while or has the car been sat for 3 or 4 weeks?

[m1tch]

You should try and rev the rotary once in a while, cause its a \'rotary\' and not a \'stationary\', check out the site below and scroll down to see what happens if you let carbon buildup on the rotors:

http://www.rotaryresurrection.com/2ndgen/tech_engine_int_damage.html

[Hi RX7]

I drive the car 3 -4 times a week and do once up to temperature rev it to 5k+ nearly every time in the lower gears but only for short bursts should I rev it to beyond that and for longer to blow out what may be an accumulation of carbon?

[SiH]

I was told once you should take it to the redline every trip. I\'ve no idea how true that is, but fcuk, it\'s a fun ethos to go by

Black smoke sounds like fuel though which may equate to rich running - what mods are on the car, and what is controlling them?

[sickboy2345]

i tell you what it might be

i had the same thing, basically you might have some crap on the bottom of the tank, maybe that geezer who owned the car before you filled it up whilst there was no petrol in the tank(petrol station one) and it sucked some **** from the bottom - dont know, but what opeople do in those cases is:

1:clean the tank manually(take it out , bla bla bal)
2:put some descen petrol (i put v-power) and rev it to the ground, on the high revs it will start spitting all that through the exhaust.

i think it might be that..

[SiH]

i tell you what it might be

i had the same thing, basically you might have some crap on the bottom of the tank, maybe that geezer who owned the car before you filled it up whilst there was no petrol in the tank(petrol station one) and it sucked some **** from the bottom - dont know, but what opeople do in those cases is:

1:clean the tank manually(take it out , bla bla bal)
2:put some descen petrol (i put v-power) and rev it to the ground, on the high revs it will start spitting all that through the exhaust.

i think it might be that..

There\'s at least one fuel filter in the system between the tank and the engine...

Even if there weren\'t the last thing you\'d be wanting to do was deliberately pump any crap through the engine...

[sickboy2345]

i did it and i have been adviced to do it by someone whos done it before :p well it worked for me

[SiH]

Your missing my point dude - there should be no way in which crap in the tank can get into the engine! There\'s a fuel filter on the pump and one inline which should stop this happening - if not you have issues that should be seriously addressed. It\'s like saying the best way of cleaning stones out of the intercooler is to boot the crap out of it and hope they get spat out the exhaust.

I\'m mindful of the legendary \'DIY porting with sand in intake\' thread...

Black smoke out of the exhaust is a classic sign of rich running, and that\'s where i personally would be looking.

[Hi RX7]

I was told once you should take it to the redline every trip. I\'ve no idea how true that is, but fcuk, it\'s a fun ethos to go by
 
Black smoke sounds like fuel though which may equate to rich running - what mods are on the car, and what is controlling them?

The car has a street ported engine and has done about 4000 miles since rebuild, there is water injection which I am now suspecting may not be working properly as the water in the tank has not gone down much recently and the body of the unit is very hot to the touch I am looking for places to re-locate it as its mounted between the radiator and the engine. There is an Apexi command module which shows 83-85 water temp around 40 intake temperature when I am in traffic but this does go down once on the open road and I avoid to much throttle when the intake is over 40.
To be precise this does only occur when accelerating away hard from a slower speed it only does it the once but thinking back I have noted it every time. The cars is going in to Re-Worx in a few weeks to have new Tein Super streets and the polybush replacement so I may ask down there if it is something that could be serious.

[mpk490p]

There\'s at least one fuel filter in the system between the tank and the engine...

Even if there weren\'t the last thing you\'d be wanting to do was deliberately pump any crap through the engine...

second that

[Mart160plus]

Crap out of the exhaust over 4000 rpm

Is it just me and my warped sense of humour, or did anyone else read the title of this thread and think it could have been a dare

Think I need another Bitburger...

[Hi RX7]

Is it just me and my warped sense of humour, or did anyone else read the title of this thread and think it could have been a dare
 
Think I need another Bitburger...

Must be then, unless of course you could describe what I assume is a combination carbon and other oily deposits forming a large obvious plume at the point of take off better!