sevens4me

iTrader: (1)

New to the scene here, and yet another first time SE owner. I picked it up this summer...in my own state...and it's a GSL-SE targa edition. I didn't even know there was such a thing (11 pc stainless), are these rare? Is it normal to have some blue smoke upon startup ALL the time? Even if it has been run allready that day, or very recently, there is always smoke on startup. Is this normal? None of my other 1st gens w/12A's did this...is it a F.I. thing? I took it to the local highly incompetent Mazda garage for a factory compression test. I was expecting a psi reading hopefully close to or around 100. Instead I got three reading printed out for each side of each rotor. 7.1/7.1/7.2 front; and 7.2/7.2/7.1 rear. What the heck does that mean? They said a poor reading would be ~4.0 but could tell me nothing else? Is this good or not? By the way, the car is VERY strong and the engine looks rebuilt(or not original) and the car has 130k on it. Any answers from you gurus would be greatly appreciated! Thanks!

83rx7boy92

are the housings painted? if so its possibly a rebuilt motor for the smoking problem im not sure im pickin up my 83 on thursday....and welcome to the darkside

-=DanK=-

Well the 3 compression results you got were for each combustion chamber. You have 3 combustion chambers per rotor and Im still new enough to not know weather 7.1 is good or not, but fear not there will be more replies after me that know what the hell they are talking about. And for what its worth, both of my 12-a's have smoked like yours does, blue smoke is never a good thing, but from what I gather its pretty normal for our old rotary engines.

trochoid

iTrader: (6)

The Mazda compression testers read in bars, not psi. Multiply your readings by 14.7 to get the psi reading. i.e., 7.1X14.7=104.4 psi, which is a good reading.

Start up smoke is common on older engines, carb of FI, makes no difference. If it's blue, smell it to make sure it smell like oil. If so, the oil control o-rings are worn. A quick test is to run the engine up to 6-7k on the road, the backoff quick. The more smoke, the more worn the o-rings are. If the engine was rebuilt and only has 130k on it now, the builder may not have replaced the o-rings

If you aren't getting puffs of smoke when backing off, or if the smoke smells more like fuel than oil, your injectors are probably leaking. Have you ever sent them in for service?

Welcome to the forum, and the Darkside. In my sig line is a link to the FSMs and some other rotary tech related reading material.

"Highly incompetent Madza garage" That's one of the better lines I've heard lately when refering to a dealer working on a 7. Sadly, it's true of most of them.

Kentetsu

If the smoke does smell like oil, run a search for Lucas Heavy Duty Oil Stabilizer... This product has helped more than a few with oil burning/leaking issues...

Naegleria_Fowleri

What about old engines that don't smoke at all? Is that normal? Should I be worried that I don't have oil or coolant left?

haha, Sorry. I'm just being an ***.

If it is burning oil for a little bit then there really isn't much to worry about. The compression numbers look good. If the smoke is white, you can have some problems.

sevens4me

iTrader: (1)

I've never noticed smoke when actually driving the car, and I've driven it pretty hard. I have noticed that I have backfiring problems if I don't JUMP OFF the gas when decellerating or shifting or stopping(this backfiring is worse the hotter the temp. is outside). It is all stock except for tuned header and cleared cats. It looks like the O2 sensor and large vacuum line are hooked up to this exhaust as well also. Is this a sign of my injectors leaking unspent gas into my hot exhaust and backfiring, or is this a coaster/anti-afterburn valve issue. I'm assuming it is a rebuilt engine (miles=?)because of how well it runs and the whole front "water pump housing"? is bulldozer orange. My rotor housings aren't painted though.
thanks for all the info.!

trochoid

iTrader: (6)

SEs tend to run a bit rich at idle to begin with, but I would vote for the injectors leaking since you aren't getting smoke when backing off at high rpms. Timing, leaky injectors,, exhaust leaks and the coaster/aav can all contribute to the backfiring exhaust. Even well tuned ones with no other problems can do it once the cats are gone and the exhaust is gutted.

thekyl

I would suggest DLIDFS it might curb the problem all together. On my SE I did this mod and it greatly helped reduce backfire on my gutted leaking broken stock exhaust. Its commen because its not building the backpressure that its used too. The anti afterburn is thinking that the exhaust has too much oxygen and needs more fuel so it turns up the injectors. Hench the smoke and the backfire. That would be my guess.



Most avid car performance shops recomend if your going to significantly change the cars stock configuration you must make sure you upgrade it on a scale accros the whole engine. Cant significanly modify how well it breaths without telling the car that it breaths better (i.e. timing, ECU adjustment, ignition upgrade, etc...)