Alright...... I have an 88 NA RX7 that i picked up cheapish.... i was told it had a rebuilt engine with about 40K on it, ive since put on about 20K. I just completed a major face lift on it (new clutch engine rear seal, tranny front seal and rear seal, pilot bearing, clutch kit.... brakes......) but the biggest thing was a racing beat header and presilencer (eliminating all cats). The car has tons more power, and it pulls hard all the way to rev limiter. Now the car supposedly has a rebuild engine which was done by some performance shop in indiana, and the mazda master tech i bought it from thought it had lightweight rotors and/or a light street port. Im not sure... Anyway the problem is that when i rev up to above 6K and shift the car blow smoke, lots of smoke, like enough to fill the road behind me....... it only blows the smoke when i shift, i can rev it up and it doesnt smoke, but as soon as i shift (meaning i let off the gas, shift, and then step on it again) it blows smoke. The car deosnt smoke excessively at idle once it smokes..... today it even seemed like it did a little backfire kinda thing when crusin at like 6K.... i have no idea what is making the smoke...... do i need some sort of cpu tuning (SAFC2???) or is this oil.... or is it a coolant seal....... thanks much for any help

bryan

 

backfiring. tuning it lean will lessen the effect. all NA's will do this.

 

do you run synthetic oil when i changed to MOBIL1 mine did it a little more

 

Right now im running Castrol 10W 30, cause its cold, but in the summer i run castrol 20W 50, i ran mobil1 and was unhappy with my oil pressure...... so you think its running lean... that causes the smoke or just the popping.... or both....

thanks again
bryan

 

Either it's running rich (not likely if it leaves a noticable cloud behind the car), or your oil seals are getting a little worn. What color is the smoke? Blue/white, or black?

 

the smoke seems to be..... white, maybe a little bluish but mostly white.... yeah like from first to second it smokes ALOT, second to third not as much, and 3rd to 4th less still, also, it seems like if i push it hard all the way through the gears and then start over it get progressively better..... like if i run it hard 4 times the 4th time is smokes less than the first..... the car is totally warmed up for all 4 runs though..... anyway

thanks again
bryan

 

That would imply oil. Either your OMP is functioning a little to much (not as likely) or your oil seals are getting a little on the worn side.

 

My 1st gen used to do that, I was told it was the sides seals. Pretty much anything over 5000 RPM would do it.

I was told to switch to a thinner oil to minimized.

Used to run 20w-50 in it, switched to 10w-40 which lessened the problem.

 

if there's oil to it, then it can be oil control seals are on their way out.

checkit: http://www.fc3spro.com/TECH/PROBLEMS...MOKE/decel.htm

 

I checked the plugs and they arnt fouled.... and there doesnt seem to be any evidence of any oil or anything.....
so im thinkin, today while i was doing some diagnosing driving i noticed that if i run it consistantly at over 5000 it starts to blow the smoke constantly.... so could it be something like that ( i admit this is speculation cause im not a rotary guru) is it injecting way too much oil at higher rpms for some reason.....

thanks alot again