Forsythe93

Ok so i've got a 1980 sa22c with a 12a that refuses to come to a stop and not kill the engine. it usually happens down a hill such as my driveway. ill come up to it in first then when i reach the hill, i pop it in neutral and let the cars momentum take me down. As i reach the bottom, I take my foot off the gas peddle and brake. the rpms drop and the engine dies just as if i had stalled.

Another of my many problems is that the car is very sporadic at ide. When i wrote the title to this post about 10 minutes ago the car was refusing to idle. It started fine, and with the choke out was idling steady at 3000 but when the choke popped in, the car kept dying unless i had my foot on the gas. Just now i went out to see something and i started the car and it had no problem staying alive. granted its idling at 1300 and is not at all steady. i'd say that the rpms fluctuate + or - about 200rpm. what is going on???

in a last post my trailing plugs weren't firing; as near as i can tell they still arent. based on what some people said i figured that they only fired at certain times.

ive replaced the spark plugs, fuel filter, spark wires, and tested my ignitor and coils....i just bought a carb rebuild kit and im planning on doing that next weekend after i remove my rats nest. hopefully that will clear up some issues.
Im also going to go buy a timing light later on...any threads with tips on how to adjust the timing?

challer2000

check your wires, I had a wire from a coil that just came a little loose and the 7 would stall at stops. But your high idle problem sounds like a vacuum leak.

Forsythe93

all wires are new and tested, i recently put in silicon vacuum hoses so unless the leak is from a bad gasket, which is very possible then i dunno...also could the timing being off have anything to do with these?

Speeder165

iTrader: (7)

Might want to check the hose ~3/4" size or so, on the passenger side near the firewall. I think it hooks into the intake manifold & runs near the exhaust manifold. I have known of 2 cars which had quarter sized holes in them & the cars wouldn`t idle worth crap!!!! Seems like after heat & time, the things just crack & continue getting worse until they are a safety hazard to drive. Haven`t had a 12A in a very long time so I am sorry I can`t be more specific. Feel that large hose with your fingers. Squeeze the thing. If it has a hole in it, You will know pretty quickly. Hint..It is usually where you can`t see it.

Sgt Fox

iTrader: (3)

I think you are referring to the soft line for the brake booster.

Forsythe93

is that the hose thats about 8'' long and look kinda like a question mark?

RustyRacer

Yea that's the one he's referring to. I had the same problem with my idle, check out the FAQ thread there is something about adjusting the idle, I believe Sterling wrote it up and it works great.

Also, have you replaced the coils? not that it has to do with the idle issue, its just good if youre putting new stuff in to make sure you get as much newer stuff in to complement your upgrades.

Forsythe93

ok ill check the hose and get back to you also ill look into getting some new coils, i checked them and they seemed to be fine but i might as well replace everything now and not do it later, its just that im trying to stay on a budget. which would be more important to replace, the coils or the ignitors. also would replacing the entire distributor help?

where can i find the timing mark for a timing light and is adjusting the timing the same as with other engines?....(just loosening the distributor nut and twisting it?)

OneRotor

iTrader: (3)

The hose they're referring to is the one that runs to Anti-Afterburn Valve #2. Run your hand down the hose and feel the bottom of it (the part that sits directly above the exhaust manifold), an that is where the hole should be.

74RX4

iTrader: (10)

This hose.
https://www.rx7club.com/1st-generation-specific-1979-1985-18/hose-question-750125/

OneRotor

iTrader: (3)

Yep. My FB did this when I first bought it. Fixed it, and have put 16,000 miles on it since then.

Forsythe93

yeah guys i dont have that hose, its just not there, and as near as i can tell i have no #2 anti-afterburn valve either. could it be because i have an SA and the hose in question only comes on an fb?(if that makes any sense)....ill take some pictures and post so you guys can do your magic

RustyRacer

I have an SA as well, how about you take a picture and post it so we can tell what you have and don't have.

OneRotor

iTrader: (3)

agreed.

Kentetsu

You might also want to read up on how to tune the idle on the carb. Sterling did a great writeup on this, posted at his website. Check it out:

http://sterlingmetalworks.com/tuning_the_nikki.htm




.

DivinDriver

iTrader: (15)

On an SA, the "question mark" hose runs the brake booster. You should have one, or something taking it's place. - otherwise you have no brake boost.

Looks like this:



Connects the vacuum tap on the rear of the intake manifold to the brake booster hard line. heat from the exhaust causes them to slowly harden, then crack and leak, on the bottom. Very common problem for vacuum leaks.

crazeyawesome

dayum that engine bay is sexy :-p

Twilightoptics

iTrader: (1)

Will the car idle normally when not coasting?

Mine's doing the same thing and I've discovered my brake booster is leaking causing a vacuum leak. It will happen even up to a stop sign flat. If I let the idle return before pressing the brake, the idle will stabilize. If I left off the gas and go to brake before the rpms drop down, it'll try and die or die every time. Idle will drop quite a bit just idling in the drive, and pressing on the brake.

Couple pumps and the rpms will drop each time to a point where the engine wont run.


I clamped the booster line off, and hit the brakes and confirmed it's leak.

Might check that out.




Definitely need the carb tune set well too though.

Kentetsu

You might want to confirm that the inline check valve is functioning correctly before you assume that it is the brake booster that is the problem. A sticking check valve can cause those same symptoms, and its a hell of a lot easier to repair (spray with lube and shake it around until it rattles) or replace.

Twilightoptics

iTrader: (1)

Didn't realize there was a check valve in there. I'll have to take a look tomorrow. Is it inline or on the booster itself?

Kentetsu

It is in the vacuum line, usually right by the hood latch. Looks just like a simple connector to join two llines together.

Twilightoptics

iTrader: (1)

Heh I'll have to go look again when the snow melts. I looked at it the other day and IIRC it's just two soft lines one from the booster to the hardline across the firewall, and the other soft line from the manifold banjo to the firewall hardline. And I don't recall seeing anything in the hardline that runs along the firewall.

Twilightoptics

iTrader: (1)

Definitely no check valve. The line across the firewall is 100% hardline. Then just soft line hose at the ends.

DivinDriver

iTrader: (15)

Check valve goes in the softline that connects the hardline to the booster.

Right about here:

ztfdrake61

Does anyone know a good place to buy the question mark hose for the brake booster? If i can't find one i'll just use some fuel hose of the same size.

Also on a side note, does anyone know where to get the coolant hose that is U shaped that goes from the oil cooler to the engine block? I have searched but only found the other hoses in the coolant system still for sale.

Thanks guys