Getting Started - Nikki issue and electrical
 

ok so im getting started on my 85. Now that I am finally able to post on the big boy pages, here is what ive come up with so far.

I have a Nikki carb, and a Mr. Gasket 42S fuel pump... Im getting gas to the carb, and the car starts with gas poured down carb. wont start on its own. I purchased this carb as a "rebuilt" off of ebay and it hasnt worked yet. im willing to tear it apart for troubleshooting. but dont know what i should be looking for. I have the FSM and it hasnt helped much.

Also cant seem to get the headlamps to turn on. i managed to get the tail lights and running lights to light up, but the headlights still do not work. nor do the hazards or the horn, or the flashers. (could be related?)

priority would be the carb issue.. id like to at least get it running and driving so i can feel good about the car and start building it up.

also, what is this thing in the last picture? it looks like it conects to a vacuum line somewhere and bolts to somthing, but it has a mitsubishi logo on the other side.. and there is no place for it to go.

here is a link to my original thread, for more info and reference
https://www.rx7club.com/showthread.p...1#post11118782

Headlights work now... it was a fuseable link under the hood on the drivers side. made myself a new on and ta-da! :nod:

turn signals still dont work, and i dont know where to begin on the carb... some one chime in at any time :egrin: lol

sounds like float are stuck. get a rebuild kit, look at the manual and start learning it is soo much fun.. enjoy

I would double check your fuel pressure to make sure its not too high before tearing into the carb. Also a few taps on the tops of the banjo bolts with a small hammer (light taps) may be enough to unstick the floats if by chance they are stuck, so try that as well.

As for your light problem, you said you made a fuseable link? How did you do this and manage to get the same amperage point at which it blows? The fuseable links are precisely calibrated wires made to burn off if too much amperage is drawn through them. Failing to maintain the same burn off amperage could result in electrical fires and burned up wiring if there was a problem that caused the fuseable link to blow in the first place.

the fuseable link that was there was just old and crudded on the conectors.. so i clipped the connectors and replaced them and re installed the link, and the lights turned on. ive had them on for 30 min or so and highs work as well.

as for the flashers and blinkers, im not getting power to the hazard switch so i think its somthing in the "CPU" or "cluster switch" in the dash.

i cant seem to figure out how to get the guage cluster out, searching through the FSM now.

ive found this for dash removal...
https://www.rx7club.com/showthread.p...board+%2884-85

do i really have to take all of this off to get to the cpu? surely not...

UPDATE: found the cpu/flasher relay.... there are 2 wires comming off the back or the cpu, and i get power on this connector. however, the wires going elsewhere do not produce any power with ignition on and hazards/blinker on...

i think i need one of these,
http://www.ebay.com/itm/Mazda-Rx7-FL...758#vi-content

I can get it started on its own now, and keep it running by feathering the gas, does not rev up and shuts off as soon as i release the gas pedal.

i have located and aquired a carb rebuild kit... suprizingly the local autozone had one.

im gonna remove the carb in a moment... it would be nice to have some support on this. anyone have a good step by step that is easy to follow... the FSM carb section is like 400 pages long... lol...

any support at this point would be awesome!

well its off... here we go, the instructions that came with the kit are easier to read than the ones that are in the FSM.... so, im gonna start here i think.

pic

all cleaned up and ready for re-assembly...this seems pretty straight forward.... the original needles and seats have some corosion on them and im curious if this is what was causing the issue. blew b12 through everything else no problem.

alright.. got it all back togerther.... had to do some more cleaning... i found that the bowl jets were clogged completely up just like the needle seats. so i took them out and cleaned them up... the kit didnt come with new ones but B12 is a hell of a tool.

ok so its ready to go back in the car tomorrow, im done for the night.

step one.. throw that mr.gasket fuel pump in the trash, and if you dont unscrew the filter from the pump its to shallow to build pressure and will starve the car... not sure what else it wrong but start there.

Ive owned one and used it just long enough to pass up the return policy and be stuck with this POS.

thank you... i will be taking ur advise!

and after reading your other thread, put more than 2 gallon ish in the tank, and if i was you i would check the pickup filter in the tank and make sure its clear. if the car sat for a period of time.

I had a problem similar to this when I first got mine. It ended up that the tank, fuel lines, filter, pump, and carb were full of dirt/ rust and she was starved for gas. I had to replace the pump and filter, drop the tank and clean it out, blow out the lines with compressed air, and rebuild the carb.

I think that most of my problem is related to the clogged jets in the carb bowls, and the floats being set wrong. and the tiny ass fuel filter on the end of the pump... im gonna re-install the carb, and remove this filter and see what happens.

that will at least give me a better idea

ok, so ive re-installed the "rebuilt" carb, and now i cant get the float bowls to fill up????

this is a step back from where i was :(

Also im missing some cables.. i have 2 linkages that dont have cables for them. if i close up all the vaccum holes the car should run? i have some "extra" vaccum ports.


im just wanting the car to run for now... so im just needing the bare essentials to get it to purr... all of the "fluff" is gonna go... just raw rx-7 to remain.

i tried again this morning, sprayed a little b12 in the carb and it fired right up, however the car died once the b12 was gone.

what would keep my floats from filling up? i measured the floats to have the same drop that the rebuild kit instructed. now im just out of options and really confused. Can anyone lend some support?

maybe we can change gears... I have an edelbrock 1406 currently installed on my boat. this carb is un-modified and was purchased from oriellies.

now, im needing to get a diferent carb for my boat... and i found this thread
https://www.rx7club.com/showthread.p...=12a+edelbrock


so i know its possible to run an eddy on the 12a.... the question is how? i need a step by step. the thread has a LOT of conflicting advise.

this would be a cost effective alternative.. seeing as how i bought the wrong carb for my boat and dont have another use for it, except possibly in this car with a RB intake mani.

Any suggestions? or am i still on my own?:scratch:

anybody know of a more active forum? or is this it? im getting annoyed by the lack of interest.

So heres the deal. You have a system that requires all the components to work properly to work.
It has tank, pump, filter, lines, hoses, carb, needles, jets etc. You need to work your way
forward so that your not trying to solve the problem with too many unknowns.

So ...

1. Make sure your flow and pressure are adequate at the carb. Do this by disconnecting the
fuel hose at the carb and timing how much it pumps into a measured bucket in say 30 seconds.
It should pump out about 2 quarts (assuming 30 gph for stock). Also the pressure
should be less than 3 psi. Measure that with a reliable fuel guage if possible.

2. Make sure the return works from the nikki. If thats clogged it will prevent flow.

3. Now hook your known good flowing fuel line and return to the carb and turn the key. Make sure
theres gas filling the bowls to the half way mark. Adjust floats accordingly. A light tap on the
top of the carb cover might loosen a stuck needle valve.

4. Now that your bowls fill lets check to see if the accel pump pumps a show when the gas
is pressed. Just look down the primaries to verify this. If it doesn't pump anything you may
have a blockage somewhere. Take apart the carb and clean it out some more.

5. The idle circuit is bit tougher. If all is well it should be getting some gas but not too much.
You can look down the primaries to see if its getting some gas at idle. Vaccum leaks are the
biggest cause of problems here. Use some propane around the carb to detect them.

Thats what im talking about! thank you!... i will take these steps when i get home and go from there! thanks again for the awesome, clear, avise.

Most people here check in maybe once a day, in the evenings after work.

Update: I am getting fuel in the bowls now... the floats are just adjusted wrong i guess... i set them up for 2" of float drop like the instructions said to do... but this was not allowing the needles to open at all.. so i took it down a little more than 2 inches and now my front bowl is full, and my back bowl is 1/3 full... so more tweaking i guess is in order.


car tries to start on its own.

Measuring drop with gasket in place, yes?

Both bowls are getting 1/2 full... now, when i hit the accelerator nothing comes out the holes... what do i do now? and yes i am measuring with the gasket in place.... i measured again in mm this time... and bent the mounting arms of the float to be level with the base of the float... and then adjusted with mm as per the FSM and its dead on 1/2 full on both sides.

Next step sounds like your accelerator pump circuit is gummed up, or the linkage for it is disconnected.

This thing here:
http://img.photobucket.com/albums/v2...emoval/720.jpg

Connects like this:
http://img.photobucket.com/albums/v2...emoval/721.jpg

Has several components in it's circuit, including jets, air bleeds, and two check balls and two weights. When they get gummed up, the pump won't pump gas out the jets.
http://img.photobucket.com/albums/v2...emoval/712.jpg
http://img.photobucket.com/albums/v2...emoval/715.jpg

Well, thats good progress, you've made it to step 4. Like DD says, something is either not
pumping or theres a clog. Did you put the AP diaphram in correctly? It will go in wrong with no
problem and you get no pumping action. The metal knob on the diaphram has to be facing out
so the arm, when it moves, contacts it and pushes diaphram in. The spring then goes on the other
side to make the diaphram push back out to fill up again.

thank you for the awesome reply once again!... the diagram that you have is way easier to read than the one that i have.. .and i think i can see what i did wrong, ill check it out when i get home.

That diagram is from the Mazda Carburetor Manual for 1979-1985, which along with many other valuable references is downloadable from the link in this thread (which is stickied at the top of the forum):

https://www.rx7club.com/1st-generation-specific-1979-1985-18/download-copy-your-year-fsm-click-thread-get-link-894736/

The one-page instructions that come with a carb kit can't hold a candle to the factory references. Especially after you've had some time to mark them up yourself.

i have a FSM, its about 900 pages and in a binder.

however the pictures are hard to read, and its pretty old (came with the car)

so im downloading and making all new manuals right now :) thanks

ok... i got it pumping when i hit the accelerator... and it starts up and runs on its own with the CHOKE ON!.... untill i turn the car off, or let back in the choke..

as soon as i let the choke in the car dies, what next? is this all vaccuum related at this point?


also car smokes a bit but im just chalking that up to it not running in so long. smells like an old lawnmower.

any suggestions on where to go from here?

Its too lean probably, thats why it runs with the choke on. You need to adjust the air mixture.

i tried adjusting the screw at the base of the carb ( idle bypass) 1/4 turn at a time with no diference, could this be caused by possible bad exhaust system? clogged cat? or the vaccum hoses that are open in the rats nest? ive got other issues i dont quite know how to figure out yet lol...


i know i have other issues, however i think the car should at least be able to run on its own before needing to address them

Too lean can be caused by vacuum leaks - - like some of those missing rats nest connections can cause - - just as easily as by mis-adjusted mix screws. Any connection that you can hear/feel sucking air when it's running on-choke need to be capped.

ISSUE!... i still cant get the car to run, this is the same problem that i had when i took it to the mechanic after giving up.

the car will start and run if i turn the choke on and pump the crap out of the pedal.

everything is hooked up somewhere and im not hearing any leaking air, however as soon as i touch the choke at all it revs up a little and then dies.

I only have 1 mixture screw at the base of my carb, and no matter what i set it at i dont get any result, i cant find anything that sais what the # of turns this screw should have is.

the manual talks about an air adjust screw and an idle air mixture screw, however i simply only have the 1 mixture screw... on both my old original carb and the one that is on the car.

please help im getting frustrated and want to break somthing.

Depending on year, some of the carbs only have one screw in the left side. Others (mostly older manufacture) have two.

Sounds like step one for you is to definitively ident which carb you have - - which may or may not be the original one from your car.

If you take off your air cleaner and take pix of all four sides and the top, and post them, we can help ID the carb for you.

standby, im doing it right now

this is all i coulg get my camera into

top

If your carb is a proper 83-85, then the 79-85 Mazda Carb Manual I mentioned before covers it in huge detail, starting on printed page# 57 (page 104 in the PDF file).

The diagram on pg 61 (108) shows the location of the 'two screws'; one (Mixture Adjust Screw (MAS), part 111 on the diagram) on the left center of the throttle body, and the other (Throttle Adjust Screw (TAS) part 113), rearward from there, touching the throttle linkage.

These are the "Two screws" the instructions talk about.

On page 68 (114 in the PDF) , Part B, steps 1 and 2 tell you how far to open these screws for your initial settings: MAS you close lightly (just til it touches the seat) and then back out 3 turns; TAS you tighten until the spring bottoms out, then back off 6.5 turns.

Those are the factory intial settings, which are the best place to start adjusting from. If all else is right with the carb, the car should start and run with those settings.

The whole of part B, and the "Adjustments" section starting on page 71 (118) are all about making sure your carb is ready for installation and adjusted in such a way that the car will start and run well enough that you can fine-tune it.

It looks to be an 83-85 carb, but there are parts missing - - probably removed as part of the 'smog delete'? - -that may be making a difference. I'm not expert on the FB's, But I noticed that your vent solenoid has lost it's connection (being unable to open the vent will make a carb have troubles), A choke pull-off diaphragm is missing, The choke thermal assembly's gone, possibly other stuff.

Of those, the vent solenoid not openeing whenthe ignition's one is the only one I can think of that could contribute to your problem - - without bolw venting, you end up with a partial vacuum over the top of the gas in the bowls, and fuel can't flow properly.

Was the vent maybe modified to be always open? Or did the wire just get sheared off?

ok i adjusted the screws to the turns you specieied from the manual. and it wil start if fully choked, and run while choked... but dies when i release the choke even the slightest bit.... ive noticed when the car is off the bowls are slightly fuller than 1/2, but when running with the choke on the bowls are dead even at 1/2.

could this be a float adjustment still

is it possible for a vaccum to be hooked up "backwards" ? still causing a leak of some sort? i just have stuff hooked up where ever it will go for the moment to see if it will run.

i adjuststed the bowls ever so slightly, and now the levels are sitting at 1/4 and the car asks the same way (starts on choke, and idles higher)... but as soon as the choke is released the car dies...


it seems to me that there is somthing wrong inside the carb not allowing the fuel to be sucked out of the nipples down in the barrels. but ive taken everything apart and its all clean, i can see through the holes.

the only other thing i can think of is a vacuum hooked up wrong... i guess i need to do the rats nest removal steps and see what happens????

im at a loss... i dont see why it shouldnt run.

i think the vent has been bodified to be always open... they man i bought it from said it was "modified" for emmisions removal.

Logically, if opening the choke even slightly causes the car to stall, and the MAS & TAS are at the normal settings, then you are either getting too much air (like from a serious vacuum leak) or not enough fuel for the air you are getting.

General causes of not enough fuel, if bowl levels are OK (and they were, when at 1/2 window), are plugged passages or jets/bleeds in the primary circuits. That's where you should start investigating, would be my bet. Especially, make sure the idle slots and the passeges that feed them are flowing (by blowing comp. air or carb cleaner thru them) and make sure the jets and bleeds are not plugged, and the right ones are in the right holes (there's a chart in the book).

Unless you can find a vacuum leak.

i went through this same problem with a 7 i had, it was doing the same thing as yours the problem i found was a little peice of trash was stuck down in a passage way. it took forever to find it and when i did you could hardly even see it but after that it ran like a champ, i would bet that is what your problem is. good luck

Im giving up on this POS nikki, ive taken it all the way back off again, and cleaned it out -again, I can blow b12 through the channels and watch it come out through the holes. When i replace all the little pieces and spray b12 in the nipple. i can watch as b12 fills the bowl. re-installed carb, and no improvement, still wont run without the choke.

im in the market for a new intake mani, and carb set up. Also looking for full exhaust replacement. Any ideas? or know anyone that has this stuff they would be willing to sell for cheap? i need a carb ready to go... no more rebuilds, im done.