timmya2

sterling type of peoples! i need you help!

my car: automatic rx7 series 3 stock 12a

As some of you know i converted to a big weber 48IDA just to try it out.. and found out it doesnt work well with a stock12a.. so i decided to just buy a modded carby called "stubers" (similar to sterlings carby mods) and replace the weber with it. I originally had a normal nikki carby prior to the IDA, So i thought hey this shouldn't be hard as its the stock one anyways.

so we manage to put it on.. but the guy who put it on doesnt really know where the hoses and stuff connect to, he just knows how to put a carby on and the principal of how it works.. (he has a series 6 rx7 but isnt that good with nikki carbies) .. anyways we still managed to get it running (after a very long process of trial and error).

Now my problems..


the car would idle above 1k.. and and after i shut it off it would make a big POP noise on the exhaust..meaning its idling too high..

we were actually about to give up because everytime i would put it on D it would die.. but he covered this hole up.. which made it better.. ( just by covering that hole up!)

here are pics of that thing he covered up http://www.neverfailhosting.com/carby/carby.htm

now after we covered that thing up.. it ran fine..

but wouldnt rev up high when i put the pedal down all the way unlike my old old carby. its like its struggling.. im guessing it needs a tune up badly..

i would press the pedal.. but the needle doesnt go up at all..

it should be like reving hard to 5-6k until it changes gears automatically.. and keep on pulling hard..

but with this one.. its like nothing is happening.. it aint pulling hard at all! just raises the needle up slowly to 3k until it changes the gears.. its like a ***** honda running on 1 piston..


PLEASE HELP ME

Kentetsu

Linkage issue?

Sterling

I love the title of the photo..."Close up of that THING".

I dunno wtf it is.
I think it's the fromunda version of the air control valve for the air pump-precat bs thing.
It looks like you might need a block-off plate on the manni, no?

This is the thing...My guess is that you're running idle off the idle circuit, cause that's a rich circuit to begin with. This is actually more likely to cause the engine-off pop. But you have a vacuum leak.
Another guess is that when the manifold vacuum reaches a certain point, that valve begins to open and you suck in air from the gaping hole in the side of the manni.

It probably sounds like a big honking open rotoray engine with 10 psi compression, because you have the mec. sec.s opening, too.
You're just opening the engine to atmosphere, and the air isn't channelecd through the carb...you're getting no fuel.

Slap some duct tape over that gaping hole in your manni and see if there's a difference.
I'll bet if you block everything off proper your idle will be tunable.

It's actually difficult to rebuild a Nikki with a vacuum leak if the gaskets are in place, new, and the carb is tight on the throttle body.
85% it's a manifold issue.

BMS2004

umm not sure the setup or anything but did you block off the vacuum secondary pod? i see yours is no there. Check to make sure that the hole is plugged. Not really sure of the vacuum that it sees at certain rpms but the vacuum secondary pod doesn't move untill full throttle and under load and stuff. Which would makesense why it dies or doesn't do anything when you press the gas b/c it would suck air in there if its not plugged. Hope i'm on the right track.

Ron

Sterling

It looks like it's blocked with something.
But the circuit that runs from the vac. sec.s diaphragm snakes through the carb housing and ends up in the frontward primary venturi at the apex. There's a small orifice there.
Even if it was open, that shouldn't cause a vacuum leak (that you would ever notice).

timmya2

hmm pretty stumped on this one.. i guess ill just take it to a rotary specialist.. if only sterling lived here ..

timmya2

UPDATED pics of different angles showing holes that arent connected to anything

http://www.tzivonim.com/~mypics/carby/open-holes.htm

IanS

iTrader: (4)

First pic, that hose goes to the oil fill vent. Also T's off to something else. At least, that is where it goes with the rats nest off. You still have yours on though. Cant remember. I hope that helps some. The other things I am sure that stuff hooks up to the air pump/cat for emissions.

timmya2

is the air pump/cat the blue thing?

IanS

iTrader: (4)

ok, back up. It appears that you dont have an air pump so nevermind that. I would say plug all those holes circled except the one on the carb itself. With the carb hole, that needs a hose - run a hose from that spot to the oil fill neck tube. There should be a spot for a hose. I have a pic but it is way too big and resizing it isnt under the 100K limit.

timmya2

can u send it to my email agfacomp@gmail.com

IanS

iTrader: (4)

email sent

IanS

iTrader: (4)

email problem, pm sent

Rx7carl

Your return line has no restrictor in it. You need that for it to work properly. Its a little silver cannister, same size as the line. Go look at the rats nest tutorial for clues as what to block, you have vacuum leak issues with all those open ports. That carb does have mech secondaries right? Ive heard of Stuber, they have a website?

timmya2

http://www.users.tpg.com.au/sturach/stuber.htm

i think it does have mech secondaries

timmya2

just found out that this carby was for a 13b extended port.. so it has jets and **** to suit it.. if i keep it in this car it will be running way too rich and i wouldnt notice any performance gain, just fuel consunmption gain..

****

Rx7carl

Well ask him to excahnge it for the proper sized one for your engine.

timmya2

he doesnt.. i had a big argument with him

i guess its my loss

Rx7carl

Why did you buy the wrong one in the first place? And Im sure you can get it to run ok on your car dude. Truth is, the carb doesnt know what size engine its on. Unless its way oversized (which I doubt it is) it'll run on your car.

timmya2

well the ****** lied to me.. i posted up i needed a carb for the 12a! and he still insisted to sell me this, so i just assumed it was for a 12a..

anyways i had a talk with stuie (the creator of the stuber carbies ) and he wrote this message:

"i noltice the engine is a 12a runnning a thermal reactor and the StuBer is for a 13b EP.... if so the StuBer will not make any diff to the performance as it will run rich due to being jetted for a 13bEP and the thermal reactor being so restrictive.....

have fun!!!!!"

MosesX605

You can rejet the carb to suit your application, no problems there.

Sterling

The return line restrictor is INSIDE the banjo bolt that holds the pipe assempbly on, and consists of a hole drilled into the side of trhe banjo bolt.
The part in the hose is simply a check valve.

Rx7carl

I know the banjo has a small hole, but the FSM calls the silver thing a restrictor.

DrOliver8706

restrictor?

Kentetsu

Yeah, the restrictor..... ? That's what I always thought it was... But who am I to argue with Sterling (I'll let Carl do it instead)..