I have an 89 rx-7 gtus n/a . Originaly the problem was intermitant but is becoming more and more frequent. The car starts and runs great with the exception of air in the oil metering lines. Big gaps of air are causing the car to bog out. when it bogs out it is usualy in stop and go traffic but now it is random and more frequent. I changed the oil meter pump with a used one that worked before. I am hesitant to just buy a new one from mazda because I'm not positive the pump is bad.

I have heard of eliminating the oil pump and using pre-mix but not sure how to do so. any comments would be appreciated.

Thanks

 

a little air in the lines isn't necessarily going to make you motor bog down, it is going to increase internal wear because there will be less oil injected. if it is serious enough to be a vacuum leak, then it may have some effect on idle and running.

you can premix on top of your metering pump or in it's stead. to remove the OMP, you have to buy or fab a block off plate and plug the fittings on the intake mani and rotor housings (four in total) with the appropriate sized fasteners. on series 5 engines (as yours is) they are electronically controlled and removing these takes some extra steps to stop your car from going into limp mode.

 

oh, and i would guess that you probably just have cracked lines or loose/poorly sealed fittings... on the other hand, premixing is superior.

 

Yes, it's likely just cracked lines. The little bits of air in the line should not make a difference unless the engine is constantly sucking air through them (ie. vacuum leak). Just replace the lines since they are probably dumping oil all over your engine bay.

 

IT takes a lot more air than is present in those lines to cause the engine to run differently.

Small pockets of air between the oil in the lines is fairly normal, from what I see. As long as it continues to flow, you are probably okay.

You may have a vacuum leak elsewhere, or quite possibly a weak low compression engine (90 or below).