Got it. That clarified things. To recap….Car starts. Reasonable compression 80-90 psi. Even pulses on the compression gauge, each pulse kinda the same with no missing or low pulses. Has to be held at 2000 rpm or more or stalls.

The rearmost cable is accelerator. In effect tightening the cable is the same as a light foot on the accelerator. I suggested disconnecting all the cables (accel, start assist, choke etc) and seeing if that changed idle speed wondering if one of the cables was too tight. But now I understand the issue is slightly different… car will drop below 2k if accelerator cable disconnected but would stall, so issue is not cables.

This puts the next step outside of my knowledge as my car has not had a stalling at lower rpm issue. Anyone else wiser than me suggest the next step? If looking for a vacuum leak is suggested, I do have a nifty home made smoke machine trick for tracking leaks.

Good news is that you should be able to fix this without engine rebuild, given the compression numbers provided.

 

I turned the idle speed screw so its holding the throttle high instead of the janky throttle cable thing that it was, and I retraced all the vacuum. some was wrong, And I may have hooked cruise control up wrong since it doesnt have a place on the diagram.

 

Here is videos of both tests

 

Pulses on gauge look nice and even.

I don’t have cruise so not knowledgeable on how it hooks up.

Wild *** guess…. Could your failure to idle below 2k have anything to die with what looked like fuel leaking below the carb? Bad gasket in the carb or intake manifold causing fuel leak / vaccum leak? Anyone more expert than me care to weigh in?

 

It really could be that, I'm just afraid if I take it off it will have another issue afterwards and I won't be able to start it.

 

Checking for vacuum leak in carb. Go to just after the 5 minute mark. Will at least will let you know if there is indeed a leak. (And symptom being addressed in this video is hard start and will not idle). If you don’t have access to a smoke maker, let me know.

You Tube

 

https://www.google.com/url?sa=t&sour...VtRc_ouDDyxar-

this helped me

 

how'd it go?

 

I do not have access to a smoke maker, and I will be for sure using that wiring diagram in the near future, just hoping its not too different for an 81 vs an 83. Im starting to think more and more this is a gasket or carburetor related issue as everything is pointing to it or fuel delivery

 

Here is the video showing how to make a smoke machine. Use this video to make the smoke machine, and use the RAD Potential video posted a couple of posts above to show you how to use it.

You Tube

 

Alright, thanks!

 

Just finished another project I had going on the side, so now I'm back to trying to make that smoke machine

 

Was actually just thinking about this last night, wondering if you had triumphed. Let us know how it goes.

 

I still havent made that smoke machine, but deciced to at least try to get my side markers working while I was waiting on parts. After looking further, the rear two were disconnected and one front is missing and another just wont work. There is frayed and split wiring nearwhere it would connect, and looking even closer I found alot of wires by my starter disconnected. Decided to get pitcures of my radio wiring while I was at it. Anything anyone recognises or can point me in the right direction as to where on a wiring diagram to look? Ive got a few diagrams just cant really make sense of all my wiring vs the diagram

 

Images are not loading, will reupload soon

 

Speaker Wire

Dangling wires by starter

Everything by the radio

Connected side marker?

Closer picture of radio wiring

Closer picture of radio wiring

Missing side marker inside fender

Lack of side marker connector and frayed/split wires

One connector missing something to go to

 

Stil no clues on the wiring yet, and still looking into radio stuff. Any help is greatly appreciated.

 

For wiring diagram go to foxed.ca, click on RX-7 Manuals on the top line, then click on First Generation under Mazda RX-7 Manuals and Books, then click on 1981 Wiring Diagram. Like you, I am not skilled at reading wiring diagrams. However that wiring diagram on Foxed is easier than most as has 3d schematics and an index of symbols.

Once I get a break in the rain, forecast says tomorrow, I will take a look at my car and see if I can answer any of your particular 'what goes where' wiring problems. For example I do remember that like you my loom had a couple of mystery plugs on the passenger side of the carb that had no where to plug in. I will see if yours matches mine and report back asap. I'll also take a look underneath at the starter and see where that blue wire with the O ring goes to.

Not much help on the radio though. Mine's aftermarket. I would suggest an affordable multimeter I use an Innova 3320 that you can get for $32 Amazon. I am a very basic user... but it can really help. For example you can use the 'continuity' setting to work out which of those cables are speaker cables and where they go. You probably already know this but just in case.... Remove a speaker grill and attach one probe to one of the wires that feed the speaker, then touch the other end to each of the possible speaker wires in the dash. When the meter goes BEEP thats the wire that feeds the speaker. Label it then move to the next speaker wire and repeat for all four speakers. That should reduce the number of unidentified wires behind that radio hole, and you can then use the meter to work out which wire is ground and which is power.

On the side markers do you have one thats still working and complete? If so, look at the wiring behind it and you should be able to see if any of the wires and plugs that you see there are missing on the other markers and simply copy what you see if you need to replace anything. You could also use your new multimeter to check that the wires that feed the markers are receiving power. Also find one bulb that you know works and switch it to a dead marker and you will know if its simply a dead bulb or bad wiring. If one marker in particular stumps you, let me know which and I will remove mine and send pics of what it should look like.

 

Thank you, I honestly didn't think of using a Multimeter to trace the wires for some reason and I was gonna end up visually following them, much more work for me. I will use the Multimeter to find out as much as I can, but as for the side markers one is all there but won't power on, as the other has no electrical internals and I can't find its connector. I've already remedied the rear ones after finding their connections. I've been using the foxed wiring diagrams and the radio helps, but the other wires I have 0 clue what they even go to so tracing them is difficult. Might try and figure out my interior lights and fix my defroster and headliner if I figure the wiring out. Thanks a ton

 

It stopped raining!

Here is the wiring connector that sends power to the right front marker light.




Here is the black connector in passenger side of carb that has no where to connect. Black wire with yellow stripe. Car runs great so maybe for an accessory I don’t have. My car is the base model.




I as unable to locate a blue wire with a ring connector near the starter. Maybe hidden way up in there…. Car is on the ground and is lowered so I can’t get all them way under there. Maybe start a new thread something like ‘anyone know where this goes?’ and a photo.

Hope this helps.

 

Thanks, my harness by my blinker is so decrepit that it looks nothing like yours, bul i will try and find where they should go. I think the rotted one with no wire is that side marker connector, and its plugged into that one with the blue wire that is just out of view in your photo. What would that be?

 

To add to the confusion that second white plug of mine with the blue wire isn’t plugged into anything. All my lights work, and the wiring looks original so maybe another accessory I don’t have because base car?
Here is what should be happening in that area.

 

Maybe we have the same type then, I just repaired the harness so now it looks like yours. I have no clue why those 2 were plugged in together or what that could do to it, but they are now not.