needspartsnow

iTrader: (10)

Hey guys, I have a '83 GSL with 125k I'm working on. I'm new to FB's (and carbs) so I figured I would come seek help from the pros. I have a few different issues, so this might get lengthy as I try to break down each issue and give as much details as possible.

1. Ever since I bought the car it would have weird fluxuating idle and lots of back firing/after burn. Some times it would idle 800 no prob, other times it would stumble and pop while idling to where I'd have to pull the choke to keep it running. So I decided to do the Mazspeed.com emissions removal. The car seemed to run better after that but not quite %100 yet. I'm just concerned about the routing of a few hoses....
There are 2 capped nipples here, one under the middle of the carb and one on the dashpot looking thing on the upper right, can I just connect these two with some hose? I assume the nipple on top has something to do with releasing the choke?


Is my crankcase ventilation right? I have hose running from the oil fill tube then T'd to the large hole on the carb and then the large hole on the purge control valve.



2. While trying to figure out the idle, I came across a thread on how to tune the carb for idle. It says: use idle speed screw to get idle below 1000, then turn in the A/F mixture screw until the engine starts to stumble then turn it out a half turn.
So I started in on it and found my A/F mixture screw was waaaay out, like 8 turns out. I have read on here that you want about 3-3 1/2 turns out. I fooled around with this for quite a while. The car doesn't seem to like running with the screw turned in more than about 5 turns out. I can get it to idle pretty good on the leaner setting but when I shut the engine down and try to start it back up it will not start up again without either: A. pulling the choke (this is on a warm engine) or B. turning out the A/F screw to at least 6 turns out. What gives?

3. I got the car idling pretty good, no more stumbling or back fire. The car leaks a lot of oil. I didn't notice how much until all this idling in the garage. I lost about 3/4 of a quart in about an hour of idling. It's coming from the top of the motor, and pooling right at the "12a" on the front housing. I did a little reading about this, people said just JB weld it. I can see the oil coming out right between the front housing and iron. Will the JB weld work? I know the right way to fix it would be to take apart the engine, but that isn't an option right now. I just need this to work for another 3000 miles or so

4. After all this I go for a little test drive and the car has no *****. Super slow revving. I get it back into the garage, do some sanding inside the coils, scuffed up the points on the rotor and go back out. It's doing the same thing so I figure I've lost a rotor. I just kept driving around full throttle doing like 25 mph and it finally clears up a bit and the power is intermittently coming and going. Must be ignition related? I put in new plugs 700 miles ago, but they must have become fouled from all the tinkering with the carb? That's my best theory any way. What do you think?

I appreciate any help/thoughts! Thank you for looking.

aa35199

iTrader: (1)

I'm going to guess clogged carb jet not supplying fuel to one of the rotors, your symptoms sound very similar to an issue a had with my old FC where a crappy wiring connector to one of my fuel injectors caused it cut out randomly. Of course you could also try what I and many other 12a owners have done with old carbs and force feed the thing seafoam, through the barrels, and get a tiny funnel and feed your carb straight seafoam through the fuel inlet line, try to run the car off of it, let it sit for a while after its ordeal to give it a chance to dissolve any gunk.

t_g_farrell

iTrader: (1)

Verify the basics first. Make sure that the fuel pressure and volume is at spec. For a nikki the
pressure should be ~2.5 psi and at the carb it should fill a 1/2 gallon of fuel in about a minute.
Also change the fuel filter and make sure the lines are all clear.

Next the crankcase ventilation should be connected to manifold vacuum like the brake booster,
in fact teeing it there is great way to start. It should pull the fumes from the nipple on the
side of the oil fill tube. You should have a PCV valve between this and vacuum so you don't
always have a large vacuum leak. Also you can run the fuel tank vent line into the nipple
on the middle iron near the base of the oil fill tube unless you kept the charcoal canister.

On the carb make sure both float bowls are at the center of the windows. They are hard to
see so you may need a mirror. I suspect you need to pull the carb and do a good cleanup on
it and a refresh with a rebuild kit. It probably has some gunk clogging its pores somewhere.
You may be able to do as someone suggested and run a lot of seafoam thru the tank. Search
on seafoam treatment on here. Its fun to see howmuch smoke it generates. It may just clean
out the carb if you are lucky.

Jeff20B

iTrader: (13)

Your emergency return spring has activated caused by your poking around in limited space. Reset it and try reving again. It might rev faster.

needspartsnow

iTrader: (10)

Thanks guys, I'll have to do some more research and figure out exactly where everything is under the hood (emergency return spring? Haha). I'll go through the car this weekend and do everything that was suggested.
The car is running right now, it's just idling really goofy at the moment. every time I start it up the idle is at a different speed and it feels like the carb is untunable. Oh well, the backfiring and stumbling is gone, so I'll take that win.
I feel better now that the pictures have been looked over and there isn't anything blatantly wrong or misrouted, thanks for the confidence boost!