I pulled the throttle chamber and upper half of manifold (was pulling the injectors) and got a look inside the four runners. The center two are not too bad, you can see metal. Outer ones have a thick layer of black dirt in them, though, which I'm guessing is carbon build-up. Like to the point where their diameter is smaller now. I can literally peel this stuff off. I've cleaned the upper manifold and throttle body, since they're off the car, but lower ones I'm not sure if it's safe to spray them with some carb cleaner on the car (it'll be a lot of carb cleaner) or should I pull the intake manifold off the motor and clean it then? Is it PITA to pull or is it reasonable, provided the motor stays in? I've no experience with this.

Thanks.

 

Lower manifold is pretty easy with the rest of the intake already off. I would order a lower gasket from Mazdatrix. The other gaskets can usually be reused, but the lower one often leaks.

Have you found this? Info on cleaning the intake parts as well as fixes for idle issues and adjustments.

These pictures may help also.

http://intertron.com/ron/seengine.html

 

i would pull 'em just to be able to clean them better and that way you're not draining all the carbon build-up that you're cleaning from the manifold into the combustion chamber and onto the rotors/apex seals. normally if the build up is not that bad you could clean it without removing it with the engine running, this should be done periodically as a maintence type thing, but once it is so caked up with carbon like you're saying i would pull it to get it clean. the removal is not that hard, i would take a look at the FSM (factory service manual) it should be able to point you in the right direction and keep you on track. http://rx7.foxed.ca/ is the link to the manuals...you should be able to pull this off with limited experience, however EFI usually will generally have more peripheral items to deal with, just label everthing you know you might forget about espeically vacuum lines as the electrical conecctors usually have only one place to go (the opposite matching connector) but vacuum lines can go anywhere.

 

I've found that making tape and different colored sharpies works the best, for me at least. Just make each connector/line a unique pattern/color and reconnect them as such.

I guess you could do numbers too, but thats boring.

 

it's better clean it off the engine. if you've already removed the upper parts of the manifold, then most of the work is done. besides, you can get some Seafoam into the motor to soak while you do the manifold.

 

Right on. Thanks. Will do that then. I don't really trust FSM to gauge the amount of work, because it makes everything look quick and easy, even the hard pita stuff. Heh.