8713b-re

hi i just bought a rx7 my first one and i have some questions first one is when i first start my rx7 it smokes blue grey smoke and does that when i rev it a little but when it warms up it stops smoking unless i rev it to 7ooo rpms then it smokes a little and back fires .
2 i was told to remove the opm and pre mix my oil and gas and it would not smoke also when i bought it the guy told me that before him the guy put a 255 walbro fuel pump when i got it he couldnt get it to run i got it to run in 2 hours and like i said when i drive it for ahwile it doesnt smoke so any help would be appreciated i am building this car for drift so any other tip and tricks would be greatly appreciated thank u

Aaron Cake

iTrader: (1)

It helps a lot of you post in English. It is very, very difficult to understand what you are writing. Take a little bit of time (this isn't chat) and make your post clear.

Now, generally a puff of smoke on startup and high RPMs indicates that the engine is wearing out. The oil o-rings are starting to wear. The good thing is that the engine could run like this for a very long time if you can put up with the puffs of smoke.

Don't remove your metering oil pump and go premix.

What model RX-7 do you have? If, for example, it is an NA, then that Walbro pump isn't helping and probably what is causing the smoke.

Kentetsu

If this motor has a carb, then that fuel pump is probably overpowering it. The stock carb only requires 4psi to work, so you might have to get a fuel pressure regulator, or replace the pump altogether.

Next time you change the oil, replace one quart of oil with Lucas heavy duty oil stabilizer. That helped a lot with my last motor, which had very bad oil control rings.

Good luck...







.

8713b-re

Well my rx7 is a 87 rx7 13b n/a

Evil Aviator

It sounds to me like the engine oil seals are worn, and you can't fix this without rebuilding the engine (usually $800 to $5,000). You can check the engine's compression with a standard compression tester if you remove the schrader valve or if you have a tester with a button that releases the valve. If the compression is low, the engine may last a year or two before catastrophic failure, but rebuilding it prior to failure ensures more reusable parts. If you plan on driving it with low compression, you can try adding one bottle of Motor Honey to the oil filler and see if that helps reduce the smoke.

If you suspect an overfuel problem due to the Walbro pump, then check the fuel injection pressure as per 4A-68 in the factory service manual.

Rotary_Junkie

lmao sorry but this is funny. Oil injected!!! rotarys are going to smoke no matter what. especially if you have a custom exhaust i have never premixed except for one time and it did nothing. 200,000 miles and still running strong so if you dont want to premix dont worry cuz it wont change a thing.

Aaron Cake

iTrader: (1)

Sorry, that's wrong. A rotary engine will not inherently smoke unless something is worn.

PurePontiacPower

ur engine maybe has half a year. that's exactly how a friend of mines behaved. the smoke started to show up all the time and was real bad if you stepped on it on the highway. it was in the driveway, I got a backfire playing with his engine and that was the end of that rotary engine. start saving up your money NOW.

MazdaFix

I have owned a few Rx7s and they will puff a little blue/white smoke right after you start them up cold. The smoke should be gone with in a minuet or two. If this smoke persists when fully warmed up under exceleration you probably have a problem. The smoke during startup is because of the oil injection/ rich fuel mixture provided by mazda during cold start up.

oldRXfan1&3

I have a 91 and I let it sit for a few days, 5 to exact. When I went to start it it did smoke... alot ... but did not after it got warmed up. Is this an issue?

misterstyx69

iTrader: (142)

The Walbro 255 In the tank is not helping ya at all.
.The smoke sound like Fuel.
If unburnt fuel is in the engine at start up then it would Come out as Grey/blue smoke On start up.
My car is "slighltly Untuned",and I get a fair amount of smoke on start up.After the car has warmed up though.all smoke is gone and I can drive around all day without any problems.
if you are having start up problems,and the car doesn't want to start,then I would be looking at changing your Fuel pump out(since it is overkill for an N/a anyways) and Getting your injectors cleaned.

Jeb

Mine is a s4 and it smokes for a second on start up and revs up and down till it warms up then it runs strong

datz

this is my opinion
do you guys think Mazda would spend that much money on research, development, marketing, shipping over seas ect if the car was gonna smoke no matter what??
come on, i dont think so.

littlebit421

I had an 88 se that smoked when i started it, only when it was cold didnt matter what time of the day or year but ONLY when it was cold. Then after about 10 or15 seconds it would stop smoking period.

MazdaFix

You got a point but a lot of the cars do. Might have to do with oil injection or to much fuel on cold start?

I do know that some smoke right after you start up cold is not necessarily a problem or a sign that your motor is going to blow.