any time I start my 1979 rx7 I get alot of what appears to be oil smoke comming out the exhust, not a little smoke but alot. the smoke gradually dimimishes as the engin warms up util there is no smoke. where do I need to start looking? It did not do this when I test drove it. Only have put on about 100miles since purchase. Help

 

i believe bluish smoke is oil and white "sweet" smelling smoke is coolant. that being said, it can possibly be just condensation from early morning starts which is totally normal. the condensation smoke is usually white...

are you experiencing other symptoms?

 

Oil burning upon cold startup is very common for rotary engines especially with some miles on them. Possibly your oil seals are going out... which isn't really a big deal at all. One trick is to start using heavier oil. If it's rotary it should take 20w50 at the minimum really.

 

time for a rebuild

 

The Problem has highly diminished since I did a complete tune up. The smoke is more white than blue but has no sweet smell. I think I will try the 10w-50 weight. It currently is 10w30. The masda was quick before but since the tune up WOW!
Wally

 

Carb could be leaking fuel into engine after shutdown, when you start up in the morning an over rich condition may exist causing the whitish smoke

 

^^^ Pull the air cleaner off after shutdown, then watch for a few minutes to see if fuel begins leaking into the barrels of the carb.

Use 20/50 oil (I like Lucas Brand) and consider using a quart of Lucas heavy duty oil stabilizer. I "got by" for 40,000 miles by doing those two things.




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Thanks for the great advice, I forgot to mention that I added a full can of sea foam to the tank, That might have caused the problem I just filled the tank since I put it in and will watch what happens. I will switch to castrol 20w50 but should i get a blend or straight crude oil? I think Lucus is the best but didn't know if it was ok with the rotory. Thanks for the help. Wally

 

Stick with dino oil, no need for the added cost of synthetic. Lucas is great if you can find it.

Also, the Seafoam didn't cause these issues. If you try to suck it in through a vacuum line it can cause problems, but I've never heard of an issue from tanking it.





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Well even though when put in the tank Seafoam generally doesn't cause the bellows of smoke that it would if it were sucked into the intake manifold... IT still wouldn't hurt to burn through that gas of tank and get some clean gas in, you never know it may help with the smoking a little.

 

Thanks again I will keep al updated as the next two weeks go by. Wally

 

I did look into the carb throat after an overnight inactivity and found about 1/4in of gas laying in the secondary side of the carb. I have to guess that the primary side also had some in it but due to the fack that they are held open slightly the gas leaked into the manifold. I prerformed the test on the selonoid and all was well there. Any other place to look that you can think of?

 

Fuel pump and pressure. Check the basics. May be your flooding the engine with too much fuel? When running it hot/hard and depress clutch/idle does it backfire?

 

Read this: http://www.nellump.net/peri/epi/firs...odedCarbs.html

 

Good read Kentetsu!

 

Drew I have been checking things and found that in a cold start if I just push the gas pedal but not all the way I get no smoke at startup, so I do think that the gas leaking over night or after a long period of sitting is a result of the gas leaking into the carb throats is part of the problem. I noticed that it doesent happen if I dont allow the secondaries to kick in. When driving and I kick in the secondaries things go south. Alot of smoke and a backfire when shifting. I do get small backfire whitout kicking on the secondaires but suspect that at that time the secondaries are at the verge of actavating or leaking fuel into the carb throat. Your thoughts please? Thanks Wally

 

bummer