Just spent 2hrs in archives, carb question...please???
 

I'm trying here guys so don't flame me...I've spent 2 hours in archives and 1mg Xanax later here I am.
RX7 Doctor has been helping me try to figure out why my car won't idle w/out the choke on(we did eliminate the coolant system problem). I spent all day(and the entire last week/weekend) eliminating possibilities...like vacuum, ect)again working on this problem and I'm awaiting THE DOC to PM/e-mail me back and I'm sure he will because he's been soo generous so far. My hats off to him!
But today I noticed that my secondary throats(4 barrel)aren't opening. I can't drive the car because I have no tires(ha...ha), so isn't the secondaries supposed to open when you punch the throttle or does it have to be under some kind of load and if so how does the car determine this? Or do I have a secondary linkage, valve motor, valve, vacuum, ECW, AACP, EWS,FTE,FFT,GGHTYYJJKIUU problem somewhere(excuse me for the exaggeration of abbreviations but reading the archives I get stressed trying to follow all the lingo).
So as the car was idling(w/choke on,duh)I take a screw-driver push open the secondaries and BUOOWWWAAA!! and noticed plenty of fuel flow there...why won't these open when I push my gas pedal? Because I hardly know what all this krap is bolted all over the stock carb(85' GS all stock).

P.S. I felt I needed to explain all this instead of just asking "Why won't my secondaries open" because I would get told to go do some research...I say this humbly w/no attitude whatsoever.
Thanks for any/all info.

Stock secondaries are vacuum operated and won't open unless under load.

Well being on this forum I have learned what the "White page of death" is...DANG! Gets me all the time.
So secondaries are vacuum operated. So I'll only know if they operate/function when I get it rolling?
Man what does RTFM! RTFFAQ! mean? I'm having heart failure over all the abbrev's...ha look I just abbreviated abbreviation teehee,oh boy I'm an idiot...
I still don't know what all the valves ect are all over the carb...I was suppose to have a shop manual 2 weeks ago but I guess that's not happening...I'm going to order a shop manual tonight!!! I've heard Haynes, and Chilton, and Mazda...I guess any will do for now. If I don't make some progress soon I'm going to shit myself...on purpose...out of..anger

do the mech secondaries mod to see if they are stuck or not.

Do you mean this;
OE Carburetor Modifications
by Sean Dunlop
seand@multiline.com.au
and Nick Reilly
njr@ts.roke.co.uk
Sean's suggestions:
Try modifying the spring that regulates your vaccuum secondaries on the carby. This model responds well to cutting the spring down by 2/3 or even try driving with it totally removed. This allows your vacuum secondaries to kick in much lower in the RPM's, and is a very noticable modification. Recommended for all 4-barrel Nikki carbies.
OK - Remove the air filter for easy access. Looking at the carby from the right side of the engine, find the vacuum bellows which operate the secondary butterflies on the carby. Remove the four corner screws and gently but firmly separate the cap from the fixed section. Inside is a spring and a rubber bellows connected to the vacuum secondaries by a metal rod. This mechanism operates the secondaries via a vacuum signal received from the airflow inside the carby. The spring dampens the secondaries response to the vacuum signal. By reducing the spring size you can bring the secondaries on quicker and lower in the revs.
For 7's with stock exhaust try 2/3 or 1/2 cut spring and with exhaust mods try 1/3 or no spring at all. Also recommend a replacement air filter element with a performance oiled foam or K&N. Also, try using a hole cutter and drill 1-3/4" holes around the outside face of airfilter housing.
Also, if you have a solenoid fitted to the vacuum bellows then disconnect the single wire connected to it. This will ensure that the vacuum signal does not become interupted.
These mods are the basics of extracting the most out of a factory S1 [1st gen]:
 Exhaust- Free flowing
 Carby- Cut or remove spring and solenoid wire.
 Airfilter- Performance foam/K&N
 Ignition- Upgrade to 82 or later electronic + coils ; Try 2.5 - 7.5 degrees more advance, leave the L-T gap the same.

nah, as in using like a bread tie wire around a linkage in the carb


want me to find a pic of it?

check and see if your acc pump is leaking gas :) it is probley a bad acc pump. and it wont let your car idle.. that what was wrong with my nikki FTW woot

cheers PaTricK

I would REALLY apreciate that.

just installed an accelerator pump last week, it was bad. i have it sitting right next to me right now...it was/is hard as a rock.
No leaking from new pump now and funtioning properly...so it seems.

when it dies.. dose it stumble or just fall off and die nice and peaceful like you turned it off?

The secondaries are not going to address your current situation. Still waiting for you to resend the pics.

Do a search, Noob.

JUST KIDDING!! :icon16:

Yeah, your secondaries are fine--- you'll feel them open up under acceleration load, usually above 3500rpm when the pedal is matted.

As for your idle issue, I'm wondering if it's maybe mixture-related or vacuum leak related. If the mixture screw has been tampered with and is set way too lean it will idle high (ie: above 750 rpm) if at all. Vacuum leaks have the same effect as too lean a mixture since they dilute the air/fuel ratio. A combination of both an over-lean mixture setting plus vacuum leaks could cause the car to not idle at all.

About the choke: As you know, its purpose is to restrict air flow to a cold engine so that the air/fuel mixture will be rich enough to idle properly until the engine reaches operating temp. (at the expense of fuel consumption while closed of course).

This feature could also come in handy if vacuum leaks and/or a too-lean idle mixture setting is causing the air/fuel mix to be inconsistent and too high for the engine to stay lit when the throttle is at idle. This is because by choking off some of the intake air the choke would restore an air/fuel ratio that would allow the engine to idle.

One other thing that could have happened is the idle speed adjust screw could also have been set too low. I say this because as you adjust the idle mixture counter-clockwise to richen the mixture the idle rpm increases. To bring the idle speed back down to its normal setting of 750 rpm the idle adjust screw is turned counter-clockwise (outward) to allow the throttle plate to close a little more and achieve the proper idle rpm.

But if this idle speed adjust screw were already turned outward to the point that the throttle plate was closing almost all the way, and then a previous owner turned the idle mix toward lean (clockwise), the result would be an engine that dies when you let off the throttle. Ditto if a new vacuum leak were introduced with that same adle speed adjust setting.

So the idle speed and idle mixture must be adjusted together, alternating from one to the other to get the correct mixture and idle rpm.

In your case it may be best to set the idle mixture first (so the car will at least idle without the choke on, allowing you to further diagnose and correct the problem) and then go from there.

To do this, turn the idle mixture all the way in (clockwise). (But not too aggressively--- when it reaches the end of its travel any further twist on the screwdriver will wreck the threads in the carb and make further adjustments inaccurate and inconsistent). Once you've turned the mixture screw in as far as it will go, turn it back out exactly three-and-a-half turns. You now have a point of reference from which to work. BTW, the 3-1/2 turns is in the proper range for the idle mixture setting under normal conditions.

Now start the car and warm it up to operating temp. Then take your foot off the gas. Will it idle on its own? If so, the mixture setting was the culprit. If not, try turning the idle mix outward in 1/2-turn increments until it does.

Once you've gotten the car to idle (even if, or rather, likely--- it's idling rough) it's time to check for vacuum leaks. To do this, get a spray bottle of brake fluid or even soapy water and begin spraying around the carb and all hoses associated with it. Spray in one area at a time, listening for the engine's idle to momentarily smooth out. (The spray momentarily closes any small leaks, giving away their locations).

Also thoroughly inspect any hoses that are near the exhaust manifold heat shield. I've had gaping holes develop in these due to years of heat exposure. Even one of these large holes will fuck up the idle big time, and the spray trick won't work on them either.

Once you're confident that you've fixed all the vacuum leaks it's time to revisit the mixture and idle adjust settings. Is the idle mixture turned outward considerably farther than 3-1/2 turns to get the proper idle rpm? If so, turn the idle speed adjust screw clockwise (inward) all the way, and then back outward again 3-1/2 turns. If the car will not idle at this setting, turn the idle speed-adjust screw inward until the engine idles at 750 rpm. You are now done. Congratulations.

One more thing: In case you don't already know, both of these adjustment screws are located on the left-hand side of the carb, The most obvious one screws downward at an angle into the carb's base at a point mid way between the forward and aft edges of the carb. The idle speed adjust screw on the other hand is a bitch to find but it's there. This screw is located a couple inches aft of where the mixture screw is and almost behind the aft edge of the carb. It can be adjusted with the same long skinny common screwdriver used to adjust the mixture.

Jeezus thanks, I'll look over that thread to get familiar w/the secondaries, ect.

81gsl12a when it dies it's just like you turned off the key.

rx7doctor I just got your PM, I know that analizing the secondaries aren't gonna fix low idle/dying problem, I'm just trying to learn alot in a little time that's why I didn't burden you w/this matter. But I was thinking that if the secondaries open by vacuum and the car seems to shut off when I take the choke off and has been said by many including yourself that vacuum may still be the issue. But if it's not the hoses(because I replaced them all)then maybe it's a valve or something, I dunno. What I do know now is that the secondaries don't open anyway unless under a load(so I did learn something here). Remember that the car sat for a few years and everything that I've touched has had to be lubed to free it up(whether it was the elect gas lid, rear hatch, door hinges, door handle linkage, PB blasted the carb linkage because when you pressed the gas pedal it stayed to the floor, valves that wouldn't move even though I didn't know their function, ect, ect, that's why I need a new choke cable, it was even froze up...just wondering if something else could be frozen/rusted/stuck). The pictures I have are basic pics of the carb and engine, may not be what you need to see but then again they may...I'll try to send them to you in an attachment by e-mail. I was gonna take more detailed pics today but kept my nose in that car until dark and didn't get a chance.
Should receive attachments momentarily.
Thanks, and how did you like that book I wrote you yesterday? lol

I have read and re-read this info...I've copied and pasted and saved it.
On the other hand...this car has been in the family forever...it's just sat for the last few years(72000 miles)and the air/fuel and idle screws have never been tampered with since new. I did pull the carb off last week and clean all jets(2 were plugged w/krap), put new needles and seats, float heights were good and replaced gaskets then re-installed. Never messed w/adjustments. Now this.hmmm. i know you may be questioning my carb rebuilding ability, well since I've spent about a week trying to eliminate this problem you're not the only one questioning! I've rebuilt 100's of small 2 & 4 stroke carbs from 40cc to 450cc but I can't help but to play-back the rebuild in my mind but I'm coming up empty handed, I was so meticulous about it. At this point I don't know anymore.
rx7doctor recommended alot of things that I've done and he's probably writing me a new check list as we speak. I have replaced ever hose I can find even the afterburn hose. I will get all the suggestions I can, paste them together, print them out and start again tomorrow(8 hrs straight today)...I think I'll get up earlier tomorrow :balls:

I found this in the archives... diaphram motor? venturi/valve body gasket installed upside-down? Can anyone confirm and elaborate on this? I mean I don't see anything on the front of my carb...especially not a motor and I hope I didn't put a gasket upside down,lol...not funny.

"The secondaries are opened by the large diaphram motor on the front side of the carb. They are permitted to open when you depress the throttle all the way down, a cam on the primaries will disengage the spring that aggressively holds the secondaries closed, and the vac motor can take over.
you know your secondaries arent opening when the engine wont post 4500rpm in gear.. any gear.
disconnect the vac motor and be sure its not ripped, siezed, properly connected etc. if the carb was rebuilt by a moron (or myself at 4am) then its possible the venturi/valve body gasket was installed upside-down. to check that take off the vac motor and spray a little carb cleaner into the port in the side of the carb where the motor breathes through.. if cleaner comes out from the bottom of the carb, the gasket is fubar, if not, check something else.
the throttle cable could also be loose.... not enough push means not enough go."

The book is fine. The more info the better. Sometimes it takes me a day or so to compile all the info received and come to a conclusion. I'm sure your problem will be solved. I was also wondering why you have a inline fuel pressure regulator on your stock carb?

I put the fuel regulator because I had to replace the fuel pump but wasn't going to pay $140 for a Mazda, so I bought an autozone fuel pump. the 2-3 lb fuel pump was $25 more than the 4-6 lb fuel pump but they looked identical...hmmm. I bought the cheaper one. Anyway, as i got to reading on here I seen that people were saying that the stock fuel pump was like 2-3 lbs or something and that the stock carb likes 2-3 lbs so I put a regulator...looks cool huh? huh??? lol

personally I would think just like any carb that it wouldn't matter but I'm a noob whata U expect? :)

Just some ideas to throw at you:

1. Idle circuit clogged with more crud like you found in the jets
2. Did you replace the little ball bearings in the accelorator pump when you had the carb apart?
3. Low compression in motor due to longterm sitting (run a search on Seafoam)
4. Leading ignition is out, and you are only running on trailing?
5. Ignition timing is off?
6. Fuel pressure set too low
7. Check the level of fuel in the float bowls through the little windows. Should be at the halfway mark.

Good luck man. I know how frustrating carb issues can be. You might even want to consider getting another used carb and giving that a try. But keep in mind, there are other things that are unrelated to the carb, that can resemble a carb issue.

Also, don't over tighten the throttle cable or you can damage the carb. The proper way to set it is to start out with lots of slack in it, then wedge a 2x4 on the gas pedal to hold it all the way to the floor. Then go back to the carb and tighten the throttle cable only to the point that the linkage is fully engaged (no more slack).

Hope this helps....

Sounds to me like the carb is leaning out real bad when you let the choke off. Will it stay running if you use the gas pedal to keep the RPM's up when you let the choke off? Seems like a major vacuum leak that affects both rotors. I've had a case where the rear rotor stopped firing due to an extreme vacuum leak affecting that rotor, then I've had a case with my current setup where the front rotor wouldn't fire for the same reason. I suggest you change out the intake gasket and carb base gasket. While your in there replace the coolant o-rings. A vacuum leak will cause the air/fuel ratio to lean out and if bad enough the engine won't idle.

READ THE FUCKING MANUAL

READ THE FUCKING FREQUENTLY ASKED QUESTIONS

Oh and before you ask, FTRP = FUCK THE REPOST POLICE.

A good possibility. Gas evaporating inside a carb does evil things.

[QUOTE=Kentetsu]Just some ideas to throw at you:

1. Idle circuit clogged with more crud like you found in the jets
2. Did you replace the little ball bearings in the accelorator pump when you had the carb apart?
3. Low compression in motor due to longterm sitting (run a search on Seafoam)
4. Leading ignition is out, and you are only running on trailing?
5. Ignition timing is off?
6. Fuel pressure set too low
7. Check the level of fuel in the float bowls through the little windows. Should be at the halfway mark.

Good luck man. I know how frustrating carb issues can be. You might even want to consider getting another used carb and giving that a try. But keep in mind, there are other things that are unrelated to the carb, that can resemble a carb issue.

Also, don't over tighten the throttle cable or you can damage the carb. The proper way to set it is to start out with lots of slack in it, then wedge a 2x4 on the gas pedal to hold it all the way to the floor. Then go back to the carb and tighten the throttle cable only to the point that the linkage is fully engaged (no more slack).

Hope this helps....[/QUOTE

Copied, pasted, printed, i'll check these things too, thanks for the throttle cable thing too, makes sense. Already did the seafoam thing, no I didn't replace ball-bearing. Everyone keeps saying the idle circuit...umm where is that exactly?

Yes it will stay running w/choke off if I keep the RPM's above 1300-1500.
I've changed the carb base and base-plate gaskets but not the intake gasket...dang that would suck.
yes been looking for a vacuum leak for over a week straight 8-10 hours a day, changed all hoses/lines. Yes leaning-out is exactly what it's doing, when I open the butterfly just a little while it's running it starts dying, open it too far and instant death.
Thanks i will keep all this in mind, in fact there are a few more things I have to check(the stuff you guys just posted) plus whatever rx7doctor has for me this afternoon/tonight and then I think I'm gonna pull it all off, carb, base, intake, every damn thing.
Hey if the leading ignitor was bad it wouldn't run at idle at all would it? whether choke was on or off right? wrong? i dunno.

You're insane

2 thing s I noticed briefly reading through this thread. The intake gasket, did you take the intake off and reuse the old gasket? That's a nono. Carb gasket, yes they come with the kit, no you don't use them. The carb spacer is it's own gasket.

He did not take the manifold off.

If the car dies when you open the butterfly on the secondaries, I'd say you are correct in the "leaning out" theory. Maybe try removing the fuel pressure regulator, just to see what happens?

Also, are you sure that you put the jets back in their proper locations (two different sizes, and its been done before)?

This probably has nothing to do with the jets. The idle circuit is its own and doesn't rely on the jet size. Also, its not likely this is ignition related as it probalby wouldn't run at all if it was. Forgive me if I sound like a smartass, but I've had very similar problems to this on both the original 12A with nikki carb and my new engine. Its got to be either a bad vacuum leak or a clogged idle circuit.

One thing you can try is richening the idle mixture with the idle mix screw. Its the screw with a spring around it mounted at a 45* angle on the carb body. It will be on the drivers side toward the back of the carb if I remember correctly. If you turn the screw counter clockwise, it will richen the idle mixture, if you turn it clockwise it will lean out. If the car will run without the choke with this screw turned further out counterclockwise, its a definate that your leaning out. It could still be clogged idle circuit passages or a bad vacuum leak though.

EDIT: That screw is actually in the carb base (just below the main body) and in the center. Its on the drivers side though. Wow its been a while since I even looked at a Nikki. I personally hate it, much to complicated.

No the car dies when I open the choke butterfly on the primary...as if you were turning the choke off but I was doing it manually standing over the car to see just how touchy it was...but I'm about to tell you all a story that might get me..umm..laughed at :anger:

If you have found the issue, and got it corrected, or at least know how to correct it, how 'bout we just laugh with you, not at you?

Well I've tried numerous times to find out where the idle circuit is and where it runs, ect...I know it's my own fault for being impatient and not having that damn shop manual that I was suppose to have 2 weeks ago.
rx7 doctor is right I have not removed the intake manifild. I removed the nikki w/the 10mm bolts and then I *cough* removed the spacer plate w/the 12mm nuts which left the studs sticking up. I realized after prying it up that it was sealed pretty damn good and maybe should've just left it alone but I didn't wanna rebuild the carb then install it again just to find out later that the gasket under the spacer plate was leaking or something...U know fix while it's already apart(even if it's not broke)...getting to my point; Since the carb kit came w/a base/spacer plate gasket that, dimension-wise, was what went between the spacer plate and intake, the old gasket was so hard that removing it was not gonna happen w/out gasket remover and probably getting shit in the intake so I slid the gasket on the studs, put the spacer-plate on, bolted it down, put the carb gasket on(between the spacer plate and carb), put the carb on, tightened everything down, hooked everything up.
Well today I yanked all the shit back off and when I removed the spacer plate(completely removed it this time...didn't just lift it up like last time)I noticed a few very small holes coming out of the bottom of the spacer and going into the intake(never got an answer on this but I'm assuming this is part of the idle circuit? Anyway, I can only assume that this would cause some sort of problem w/air/fuel flow/mixture? Have I found my problem? My F*#@ up? Maybe. But I know this, if that is my problem why don't they send the proper gasket? And also since I need a gasket there now should I use one of these nicely fitting gaskets and dril some small holes in it for these holes coming from the spacerplate to the intake? Because if I put nothing I'm afraid as hard as the old gasket it that I won't have a seal.
You have permission to bust my balls!

Long answer made short. The "Spacer" is the factory gasket, you don't want to know what they cost. If you use the thin paper gaskets, by all means, do make the tiny holes in them. Both the spacer to intake, and spacer to carb hole are important.
Unfortunately, this is not related to the idle circuit. That is internal carb passages for the fuel flow at idle.

Oh, and inspect the spacer very well. A cracked spacer can and will cause massive vacuum leaks.

What is the "internal carb passages for fuel flow at idle"? you mean the holes from spacer to intake are the internal carb passages for fuel flow at idle?

Sorry, I wasn't very clear about that part. The idle circuit is inside the carb. It handles the fuel flow during the idle condition. One part of the idle curcuit is the idle mixture screw, which regulates how much fuel is allowed thru this small maze of passages. It doesn't take much crud to completely block these passages, as they are rather small.

I see, well when I rebuilt the carb I removed all jets one at a time so that they would be put back in their proper place, I used carb-cleaner and compressed air and left no stone unturned ...except for the spacer gasket thing, ha...ha.
I think this is my problem and I'm going to fix it now, if it's not the problem then after I get it back together I'm gonna blow a gasket of my own.

Has anyone out there made their own gasket for this spacer-plate gasket? I have some 20thou" gasket material that's way better stuff than the carbkit gaskets which are also .020" I believe. i don't wanna pay Mazda price but I don't want to have to take this carb off again either... for a while anyway.

I don't remember (been way too long) if there is anything to remove in the idle circuit, other than the mixture screw. It can be rather easy to miss one or more of these passages during the cleaning and blowing out process.
Before re-installing the spacer, inspect it real well. Even the smallest crack in it, can cause vacuum leak night mares.
As for making gaskets for the spacer, I haven't done it. Some of those tiny holes are essential, while others are just for emmision stuff.

10-4 goodbuddy. I'll go inspect and I'll be back asap for any other feedback. thanks

The rebuild kits for the carbs are universal for all years. I have yet to use an included carb to intake gasket from the kit on a 1st gen carb rebuild. The spacer is it's own gasket. Inspect it well, you may have compromised the seal when you pried on it. If it's damaged, post a wtb in the for sale section for a newer one. I do know that some of the gaskets have the vac ports that match the spacer. If the spacer is compromised, I would use one of the gaskets only as a last resort until you can locate a good one. Do not use gasket sealer when mounting the spacer or gasket, it will plug the vac ports.

Make sure that you don't install the spacer and/or gasket in a position that is either flipped over or upside down...

No kidding... You're saying just place the spacer onto the manifold dry and then mount the carb? Will this still seal properly? I mounted the one on my wife's '85 using a very thin coat of silicone. Hard to tell if this had any negative effects on vacuum leaks because I haven't yet gotten around to replacing all of her old and brittle hoses...

I just replied to a message from Trochoid and I'll paste it here for you...funny that you mention the upside-down gasket...I mean it is reeaally funny, hardy har...har, Not!


I just got back in, carb is installed again...I took the carb back apart for good measure and guess what? The good news is yes all jets/ect are free of clog still but the bad news, which is now good news is that I found out that I happen to put the top carb gasket in upside freaking down..I'm more mechanically inclined than this..uh on dirtbikes.
I feel so stupid anyway I put a new one in the right way...it freakin fits both ways but it doesn't have that little 90 degree/"L" shaped piece on one side....duhhhhhhhhhhhhhhhhhhhhhhhhhhhhh!

So this finding PLUS the gasket plugging the holes on the bottom of the spacer-plate together was hopefully my problem.
My plugs are fouled from the sea foam treatment, gotta go to autozone first thing in A.M. to pick up the rest of my brake parts and I'll pick up a new set of plugs, I know I can clean them but I'm so sure it will crank and run properly now(I hope) that I might as well get new ones, they have Bosch but I'll order some NGK later, cause that's all I will run in my race bikes, might as well have them in my traffic violating car.
I probably won't be able to sleep tonight!
Oh and you know I'll be letting you guys know if I'm still having problems!
Thanks

What no comments? C'mon somebody wants to say something.
I can feel you laughing.

Correct, no sealer. Another reason not to use a sealer is if you need to take it apart at a later date, it may tear up the gasket that's bonded to the phenolic spacer from the factory. The FI setups have the same type of spacer and I have yet to find one that has had any type of sealer from the factory, carb or FI.

The seafoam shouldn't have fouled your plugs, you can actually clean them in the stuff. Gas and oil will foul them though, and they usually end up that way after flooding. I use a drill with a wire brush to clean mine, then hose them down with brake cleaner afterwards.

Glad you found the problem (hopefully). Now get ready to zoom zoom! :)