83 Mazda Rx7

[dickita15]

An old trick for checking for vacuum leaks is to let the car idle and spray carb cleaner on various lines and connections. When you spray the area with a leak the idle speed will change as the cleaner is sucked in.

[Scott Nutter]

Brandon,
The spark advance is adjusted by rotating the distributor, that is where you loosen the 10mm nut at the base of the distributor. Hook up the timing light to the front leading plug and check the front bottom pulley while twisting the distributor. I believe this has the aftermarket small pulley that I have marked as per the Yaw instructions (years ago). I don't remember what the markings are, I'll try to find the old documentation. It is quite possible that the distibutor is off by one tooth, because I'm sure it has been removed in the past.

[kbailey]

Congrats on the license and the car! I had the pleasure of running with your dad out at Nelson Ledges last year...well I was in the same run group, can't really say I was running with him

Anyway my 83 street car had a rusty tank. It got to the point I had to change the filter every 2 months. (The stock filters are really small). As people have already warned you: make sure you have good fuel levels in the bowls even if you have already checked it before.

What is the lowest RPM it will run?

I would start by setting the idle mixture screw to the initial position. Do you have a Mazda manual or Haynes? After that adjust the throttle stop.

There are about 4 miles of vacuum lines in the emissions systems. A small crack can easily mess you up. If you so start replacing them be very, very careful removing them from the plastic solenoids. Those plastic valve bodies are 26 years old and very brittle now. I slit my hoses with a razor before pulling them off and replacing them. (well after I broke half of them I started slitting the hoses).

There are also several big valves on the outside of the carb that work with the air control valve. Checking them is time consuming, but pretty straight forward. I am not a huge fan of the Haynes books, but they are pretty good at describing how to check that whole mess out.

If all the emissions stuff checks out, then check the timing and vacuum advance.

If it still does not work then it could be carb rebuild time. I messed two up before I got it right.

Moron move #1: do not wait for your mom to leave the house and then put the carb body and horn in the dishwasher to clean them! While it cleans them very, very well, the dish washer detergent is corrosive to the aluminum and pits the sealing surfaces.
(okay, hope everyone had a good laugh and no one peed their pants...)

Moron move #2: there are some very small balls inside the carb. I can't remember exactly where, but they are very easy lose when disassembling a dirty old carb. Work on a big clean surface, take pictures and make sure you can find small parts that you drop.

Good Luck!

[tom_sprecher]

IIRC, the balls are in the accelerator pump circuit and act as check valves to make sure gas refills the pump diaphram instead of air.

Unless your state requires emission inspections on older cars (25 yr cutoff here in GA) I'd get rid of all that crap and be done with it.

[Brandon.Nutter]

Well thank you all for the help/ideas. They all helped in my never ending struggle with the 26 year old beast of mine. As of now it runs great. Takes a little bit to warm up and idle, but it does. The only problems now are a missing brake pad clip, the driver rear brake pad clunks up and down when going down the road. And the exhaust is still a bit on the loud side, the neighbors only complain twice a week now...haha just kidding. But again, thank you all for your help and knowledge.