So after I magically fixed my idle problem about 2 months ago, it started to idle horrible again. I tried almost every thing to get it fixed but with no success. so I'm just going to take it to mazda or someone else to have them fix it because its driving me crazy.

And will mazda charge up the *** to fix this kind of problem? (I'm pretty sure they will)

 

Your better off finding a rotary shop rather than going to mazda. Even if you have to drive further.

 

What fixed the problem the first time? I replaced everything on mine and the idle was still horrible. Then I checked all the connections and the terminals in the TPS connector were so corroded they weren't making a good contact. I took it apart and cleaned them and its been working great ever since.

 

maybe someone here can help you diagnose if you post a detailed description of what kind of motor you have, mods if any, and what you're experiencing and whet you've tried to 'magically fix it'.
or have you already posted all this somewhere...maybe link it to here since this thread is higher on the recent list.
whats going on, what have you done?
i would suggest not taking it to mazda if its rotary related...i read somewhere that they are more likely to try and convince you to have them just replace the engine because, also from what i read, mazda never trained anyone to work on rotaries because of this whole thing where in japan most people buy a newer car than go through the extreme stipulations and regulations they have to follow in order to pass their inspections.
so i think chatchie is giving good advice if it does happen to be rotary related...if not, then any mechanics shop could probably help you out...or if you got a few tools and a brain im sure you could fix it yourself...try doing what i described above and go from there my friend...good luck.
btw, im sure mazda would charge alot more than a smaller shop if its not rotary related....the only thing i personally think mazda is good for is using them to get hold of those hard to find brand new oem parts you may need.

 

I posted it somewhere but can't find it again. But basically when there car is warmed up it starts to idle bad. (800 to 500) what I did which "magically" fixed was mess with tps and then the next day it didnt idle bad anymore.

I also have s5 n/a with straight pipe.

 

I had the same problem just this past week. I checked all my vaccum lines and then found found the half my intake was off and needed a new clamp to connect the upper halves. I took it to my local rotary shop and they adjusted the tps and the thermo wax because it was constricting air flow to the engine.
Do hope this helps.

 

So the only thing you've messed with is the tps? There's a whole mess of things that can effect idle all of which are easily dealt with on your own.

 

it is best to adjust the tps after the engine is warm. i think it is 1 volt from one of the green(?) connectors, i had a bouncing idle till i adjusted it to 1 volt. i also had a idle and running issue with my TII engine with the turbo being louder, turns out one of the plugs came off the charge pipe. i also found my coolant leak that day.

 

The green three(3) pin connector on the left side of the engine bay under the intake is the one you're talking about correct?

 

Well I had my buddy who knows his buddy who works at mazda that is certified to work on rotarys, and he said its not the TPS or any vacuums. He said it is probably something simple. He also mentioned that its not as bad as most peoples idle.

so were else can i check for bad idle

 

i believe so jar2, it has been a long time since i did that.

what exacty does the car do? adjusting the TPS is simple. most of the time a bad idle is do to vaccum leak, tps, thermowax issues. when you say 800 to 500 do you mean it bounces? from 500 to 800 to 500 to 800 etc? if it does it is the tps and tremowax fighting with each other.

 

This is the exact same issue I was having. Just as raksj04 said, its most likely the thermowax and tps workin against each other with a combination of a vacum leak or two. I just had my tps adjusted so it idled higher and wouldn't die anymore because the thermowax was constricting most of the air flow so it idled around the same range and then it died oiut on me in neutral. Use a test lamp and check adjust the tps and it'll fix, but the car will idle high after that.

 

OP, do you have the FSM? also...the friend of a friend thats a 'certified' rotary mech, this is two part question dealing with him. 1) did he adjust anything for you or did he just check it out, and 2) where does he get 'certified'?
I was thinking about your problem...got a couple ideas of things you can easily check yourself, especially if you have the FSM...
i would remove youre thermowax and go through the check procedure thats documented in the FSM. also while your into that...might as well go thru the procedure of checking your water temp sensor.
what about electrical load.? 500 to 800 idle doesnt sound too bad as long as its not stalling but 750 is perfect. i'd say try taking off your BACV and cleaning it out with carb cleaner or somthing real similar that is an evaporitive. you can also test to see if its working properly via FSM and a multi meter....that allen screw on the front of it could need adjustment...i adjust mine from time to time when im adjusting my tps. it helps smooth things out. the BACV is essentially the same as an electrical load control valve. it helps to smoothen your idle when electrical things are running...i know when i have my headlights on and come to a stop my brake lights activate and my idle drops a little and this could be combated with a much better battery and good electrical lines.... thanks aaron cake.
you could also check your boost sensor....see if its workin properly.
also when is the last time you adjusted you CAS and timing.?
if you do happen to have the FSM, my suggestion is to run through all the 'emissions checking procedure' is section 4.
this probably doesnt relate to this but, remind me again as i have an s4...does the
s5 have aux ports actuated by backpressure from the exhaust?
thanks and ggod luck

 

Certified rotary mechanic, eh? Is he certified to work on 25 year old rotary's? There isn't much of a difference between a renesis and a s4 or s5 13b in the basic mechanics of the engine, but the electrical system and idle system is a whole different story.

I would never. never. never ever never ever never ever ever take my car to a mazda dealership. Talk about getting ripped off, and getting little to no work done, or worse coming out with the thing screwed up even more than it was when you went in.

The guy says its something simple? Have you ever adjusted the TPS? its pretty freaking simple. and considering that when you last messed with the TPS the problem magically went away, that is the first place i would look.

 

the 'certified' mech said it was PROBABLY something simple, which leads me to believe its just as likely he thinks it something not so simple...my guess is this mechanic is going to make efforts to overcharge you and not let you watch what he does or explain anything.
he may even go so far as to say you should just get a new engine and drop it in. then charge you 7-9 thousand $'s to do it....and chances are its not going to be a nice rebuilt fresh engine...for that much money you could have a really pimp motor and a lot of change left over.
i hope this goes well for the OP(original poster)
i highly suggest if you dont have the FSM(factory service manual), you should get one before you think its ok to take it in to mazda...after a quick read thru of that thing, im sure you will find that you could do everything you need to that car with the proper tools. the FSM is free...you could get it saved on disc for free, and you could print it at home with a couple ink cartridges and a book of paper. thats what i did, all and all cost me $30.
let us know whats goin on OP. good luck

 

if he thinks the TPS wouldn't be your root cause why do you think it is a good idea to let him charge you top dollar to work on your car?

like everyone already said, he may be certified to work on rotaries but that does NOT mean he is knowledgeable to work on 25 year old RX7s. sure he may know the basics of the renesis but that means nothing in the big picture. he can't plug in an OBD3 handheld to look up live info or to get codes or do any real diagnostic work on the car. the only thing he is right about is the fact that it is something simple, but that still can be hours upon hours of diagnostics and hundreds of your dollars before he finds out what the "simple issue" is.

of course if it's that frustruating and you have enough money, i'm sure they can eventually figure it out.

i have worked on these cars for 10 years and NOTHING IS EVER AS SIMPLE AS YOU'D THINK. almost every car has a mind of it's own and they all have unique issues that take time to figure out. one car may like a 1volt TPS setting where another hates it and prefers a 1.6volt setting for idle.

 

i have the same problem, ive replaced all the intake gaskets, vac lines, inj seals, and then tested for vac leaks to find none, ive adjusted my TPS like 100 times, adjusted the thermowax/fast idle cam like 100 times, cleaned out my BAC and tested it, bypassed the fuel pump relay, but it still lopes at idle. i noticed when i turn on the AC the idle smooths out .
but im gonna replace the AFM to see if that helps.

 

datz, i would think about replacing the BACV before you replace the AFM. reason being that when you turn your AC on, you say your idle smooths. that, i think, would be a direct result of your electrical load valve not working properly, which is what your BACV performs. i could be wrong but i think thats what it sounds like.
when i cleaned my BACV, i noticed that it was quite clogged. i blew air through the outlet nozzle on the back side of the BACV and noticed no air was passing through. thereafter i sprayed a good amount of carb cleaner through there and pressurized it via blowing through it with my mouth(tastes like ****, DO NOT swallow that stuff) it unclogged and the more i put carb cleaner through and blew through the more it unclogged....
i would suggest taking off your BACV and checking if air passes through that little nozzle. also if you have a multi meter theres a section in the FSM that will walk you through testing the BACV...there is also a allen screw on the front side that could need adjusted. be careful when installing...i ended up breaking the threaded bolt of my dynamic chamber by torquing the nut to tight.
also datz, if you have the FSM, theres a section that shows you how to test your AFM its really simple and takes about 10 mins if you have a multi meter.
good luck and let us know how it goes....same for the OP.

after i cleaned my BACV, adjusted the screw on the front, and then adjusted my TPS and thermowax...it started to idle real well.

 

also guys, check your water thermo sensor...its the plug on the back of your water jacket under your altenator on the back side. there is a coolant line right near that sensor that goes directly to your BACV...might want to check the sensor via FSM and take the coolant line off to see if its clogged...mine was clogged pretty bad which didnt allow any flow to the BACV in the first place....follow that line through the BACV and you'll notice(on the s4 anyway) that theres another line that runs top back side of your throttle body and to your thermo wax then down to the rear iron...check all those lines and see that they are not clogged....chances are they got some nasty black **** in there and rusted nozzles...take care of that stuff and hopefully that helps you guys out.

 

hey thanks alot, i expected the BAC but people keep tellin me its the AFM.
but its been a couple months since i tested those things so i will again and clean out the coolant lines and BAC. and test water thermo sensor, its just a bitch to get to!
and i'll take your word on not swallowing the carb cleaner!

 

it is a bitch, i usually just take off the entire UIM...if you do, dont forget to de-pressurize the feul line...not sure if youve done it before, so ...start the car, get in the hatch under the speaker cover and tower carpet a little and it should be there, just disconnect it and let the car stall....there are other ways to do this though.
let us know how it goes and if you found the problem...i notice ppl dont do follow ups and post what they did to fix it too often.

 

you should look you the MSDS for carb cleaner in case you indigent it. my brother decided to siphon gas from his snowmobile with a garden hose. shallowed a bit of gas. he is ok.

 

i cleaned out the BAC (it was pretty dirty) and tested it, and made sure the harnees connector to the BAC is getting correct voltage at right times. (key to on and there was ~10.5v, and key on and AC on ther was 0v, sound correct?)
tested pressure sensor it was good.
tested AFM it was bad.
but i havent got to the water thermosensor yet. and i have taken the UIM off to replace gaskets and vac lines, but if i take it off again can i reuse the UIM to LIM gasket or would i have to get a new one?

 

oops, been a while since i looked at this thread.
well, im not 100percent sure of that...dont feel like diggin out the fsm right now but the specs are in there. also, ive taken my AC out.
id say if you can take a second look at the AFM, its easy to get those prongs mixed up(at least for me it was, did it twice just to make sure).
anyhow, if all those things tested good and the afm didnt...sounds like you found your problem my friend.
most of the time i replace the plenum gasket there 1) because theyre cheap and 2) i dont want any problems associated with my air intake.
its a good idea to have a few of those laying around anyway.

 

it tested good but still lopes.
so new BAC is next, and testing the fuel pump, and regulator according to FSM