JCs84

I have spent hours reading and searching archives and find many opinions and helpful advice, but here is my deal:

I recently purchased a 1984 GSL with a 12A in near mint condition inside and out for $450 as a first car for my son. The previous owner indicated that it ran earlier this year but began starving for fuel and does not currently run. I hoped a quick fuel pump replacement might fix it. He also said that it had a carb overhaul, but I notice the mixture screw is bent, and the fuel is way high in the site window. I have manuals (that suck) and some carb overhaul books, but I'm too anxious to read them through. I have maintenance records back to the late 80s which indicate it had 89k mi in 1987, but only has 110k now, so it has set.

I have a good bit of mechanical experience, even complete rebuilds of american muscle cars and some Ford 4X4s, but never a rotary. going through the top side I can only find one damaged item; a three way solenoid with a broken vac port...anyone have extras for sale, or better yet do we really need the conglomeration of air pump and emissions tubing? I hate to start tearing it all apart as it appears to be all stock and in good shape.

Where i am: I replaced the fuel pump and drained the tank and lines. I can get it to fire a bit but not run on its own. The car has no exhaust on it. I figure I better start from scratch by presetting the timing and working up, maybe even a carb rebuild.

Any ideas or tips on presetting the timing, carb, etc., in trying to get her to run?

boostedHULK

iTrader: (1)

you didn't mention, although i would assume you changed at the same time, the fuel filter. always seems to be crap in the tank, and the filters are cheap, so i'd do that. When i first picked up my 7, judging by the way it ran, you'd think it had some serious issues, but all i did was put in some fresh plugs, points, wires, fuel filter and an air freshener and it ran like a champ.

lascelles

the conglomeration is call a rats nest.

Everyone but Ray Green thinks it is un-needed
There is a great link in the FAQ section on removing
also there is a link to The FSM (factory service manual).

The carb rebuild is easy and (40$ Autozone.com) once you get it out. Sterling is the resident Guru
It will run rich until the float level is set so address that first.

Change plugs NGK only

and read all the FAQ section it will save you lots of pain

JCs84

Yes, replaced the filter with the pump and flushed the tank and lines. I have good fuel flow at about 4 psi, and good return to the tank (now).

I also pulled the plugs, which were Autolight and nothing like the old NGK I tested each of the old NGK plugs (which were in the storage box), grounding them out of the block to ensure spark and they are all good, so I asume the coil packs are good as well.

I confirmed the firing order and tried it again, adjusting the timing each way a bit. This did not make any difference.

RXDad

iTrader: (2)

Rebuilt carb with fuel level high in window equals wrong float drop settings or fuel inlet needle is not closing. Check float drop and readjust per the FSM. Fuel level should be in the center of the window. Search the forum for e-copies of the mazda FSM. When trying to start, look down the carb and see if you get dribbling gas or a fine spray.

RXDad

DavidMyers53

If you rebuild the carb, note that the bolt in the middle of the carb that holds the air filter on also holds the top and bottom parts of the carb together. Take LOTS of pictures and pay particular attention to the throttle linkage- it's a bear to get back together correctly.

The air (bowl) vent solenoid can also go bad and cause strange problems, usually flooding, though. It's under the fuel inlet/outlet lines. FSM tells how to test it and posts on the forum tell how to disable it.

I added a clear secondary fuel filter at the carb so I could be sure it was getting gas. My tank had so much gunk in it after sitting for 13 years that I had to marine clean/metal etch/POR15 it. Before I did that, it would kill the filter at the pump in 1/4 mile or less.

Also, there's a coil for leading plugs and trailing plugs. There are igniters on the distributor for leading and trailing coils. Igniters go bad, and you may only have leading OR trailing ignition. Car may not start or may start and have little power. I replaced mine with GM HEI igniters (also did DLIDFIS ignition- there's a FAQ for this) which cost $17 rather than big $$ for used ones.

Lots of luck!
- David

JCs84

Thanks to all for the input. I have not had time to work on it lately.

David, can you provide more direction on what you did with your tank? with the car down, it may be a good move to do the same as there is/was a lot of junk in it when flushed several times.

also, I do not see ignighters on the dist (have not looked either). Wires go from the coils to the cap and from the cap to the plugs. I do have spark at all 4 plugs though.

I am currently trying to find out if, in Missouri, I can legally get rid of the rats nest and strip down the carb and whether I have to put a cat back on the exhaust. If not, all of the little **** may go regardless of stock or not.

t_g_farrell

iTrader: (1)

Hey, I graduated from Rolla back in 83.

Haven't lived in Mizery since 84, so i can't tell you anything about the laws there.

Like RXDad says get the carby float levels right and make sure its all good and clean and setup correctly. Download the FSM for the 84 model year and use it to make sure the carb is adjusted right. One of those vacuum switches out could cause you problems. If you can, rip out all the emissions, theres how to in the archives. If you can't you'll need to fix that solenoid.

Also, when a rotary gets flooded its almost impossible to start unless it sits for hours between tries or you remove the plugs, clean em up with carb cleaner and while they are out spin the motor to get all the fuel out. Do this with fuel pump disabled and the igition disabled or you'll have a big fire hazard. Then put the plugs back in and try it out.

Good luck, they're a lot of fun to work on.

DavidMyers53

RE: Gas tank clean up:

I had the tank "boiled out" at a radiator shop, which caused as many problems as it solved-- it got the gunk out but left a lot of rust in the tank. While it was there, though, I had the fuel pickup and return lines replaced. The original pickup line had a wire screen on the end (that was messed up) which would have been a problem later. I bought a kit off the Internet ($65-70) that had Marine Clean, Metal Etch, and POR 15 sealer in it. It was a 2 day process to clean and prep the tank for thge POR 15 sealer (which would have sealed the screen on the original pickup line). While I had the tank off, I primed and painted the outside with Rustoleum (gloss rather than flat so it doesn't hold dust). I also used compressed air on the fuel lines to be sure they were clean, replaced the fuel pump and filter, and the rubber lines that run back to the tank. This is a great time to replace the fuel gauge sending unit if it needs it. Something else you might want to do is be sure the charcoal cannister inlet isn't stopped up and that the line to it is clear (there's a post on this somewhere). This can cause problems with the fuel system-- can't remember exactly what, but mine needed it.

I did this 2 summers ago and haven't had to change the fuel filter since.

Good luck!
- David

DavidMyers53

Also, on the igniters-- trust me-- they're there. Look on the front and passenger side of the distributor. Small, black, oblong things. They provide a high-powered input to the coils.

- David

speedracer_not

https://www.rx7club.com/1st-generation-specific-1979-1985-18/dizzy-ignition-guys-can-i-splice-these-wires-780833/ for nice pictures of ignitors

trochoid

iTrader: (6)

Since MO still has vehicle inspections, we are supposed to have a cat. Find a friendly inspector. Cats and air pump are the first thing I remove and replace with headers.

When carbs are rebuilt, the needle and seats are replaced, they always hang up until they wear in a bit. You can pull them back out and burnish the sides of the needles. Check the float levels and hope that who ever rebuilt the carb didn't touch them as they rarely need adjusted.

If you haven't found it yet, the following link will give you the online manuals.

http://www.wankel.net/~krwright/cars/rx7/manuals.html

JCs84

Thanks again to all. Relative to the igniters, if I have spark are the igniters good or do I still need to test them?

I can't find a FSM specific to 84 at the link, will 85 work?

I will try the rank rehab if I have to pull the tank. The gauge is not working but I have seen some posts that indicate the plug/connection above the drivers rear wheel is a tpyical problem area.

RXDad - relative to the fuel, initially had a dribble, but now have more of a stream, not a fine spray. I think this weekend I am going to strip all of the emmissions and unneeded items off as posted....I'm sure to have more questions.