sicminded

hi,

purchased a 93 r1 about a month ago. it is vr, with only 37k original miles. it is completely stock, no mods what so ever, not even reliablility mods. it is not driven daily, it is my weekend car.

this last weekend i've noticed that my car is starting to idle low, about 400-500rpms. and bounces a little, +-100rpms. there were several occasions that it has drop to 100-200rpms and wants to die/stall. but never has yet (knock on wood). it recuperates to 400-500rpm idle in a few seconds. the engine does not have a hard time starting up tho, starts up fine.

doing a search i've found idle problems with moded cars and streetported engines, etc, but didnt find information on what i was exactly looking for. but reading other related idle problem threads, the only thing i can think of right now that might be the problem is spark plugs or sign of an engine needing a rebuild.

i hope that it is not a sign of an engine rebuild. i've been researching and searching this forum for 6 months before i bought my car, and was hoping to find one with low miles in hopes to avoid problems until 75k-100kmiles.

anyone have any thoughts? i will also be brining my car in to ricks rotary to have him take a look because i am also wanting to get the 30k mile major service done on it, if it hasn't been done already.

thanks for reading,
chris

Street King

You can either raise your idle, easy or there could be other possible malfuntioning parts.

You can tighten up your slack on your throttle cable.

You can check your dashpot(get a service manual) and make sure it's working correctly.

If you rev it and it comes down to a rough idle for a few seconds and then it straightens out, this is probably your dashpot.

You need a boost gauge to monitor your vaccum and make sure its 15 or more. It the vaccum is bouncy you are probably looking at a vaccum leak.

Tim Benton

iTrader: (1)

I thought the lowest rpm on the stock gauge is 500 so how can you tell if it is dropping to 100 or 200 rpms. If that's the lowest 2 lines you see, then your at 600 or 700 rpms.
Explain it a little better about the rpms if you don't mind.

Tim

sicminded

thanks for the quick advice,

streetking: as far as rasing the idle, i've read on one of the newbie sites that if your idle is bad (and something about if you already have a bad idle or completely stock or something) that raising your idle to fix it is a bad idea. going to re read what it exactly said, kinda forgetting now.

as far as dashpot im not exactly sure what that is, but the problem you were describing about revving and then dropping a little then straightens out, i am experience this occasionally. going to do a search on 'dashpot'.

i am planning to get a mechanical defi d-gauge boost gauge from jason from rx7store, its just that he has it backordered right now. its probably a good idea to check the vacuum as you've said which might be the problem. if so i should get silicone vacuum hoses right?

tim benton: i may be reading the rpm gauge wrong, but i just hopped in the car right now and checked. the lowest white bar (which i will refer to as 'mark') is located at 0. of course it never idles there because the tach goes to that mark only when you shut off your engine. when i was describing 400-500rpms i was referring to the 3rd and 4th mark from the 0rpm mark. when i was describing 100-200rpms i was referring the the 1st and 2nd mark. just to make sure you get what im saying; the 1st mark i'm describing is the 1st one after the zero mark. the zero rpm mark is not the 1st mark. and to make things more confusing i noticed on my friends 94 touring that he has less marks between the rpm numbers than mine. check out the link at my signature, i have a picture of my cluster.

just to think about it while i relooked at the rpm tach at my website, it idles at the 3rd mark mostly. ahhh, my head hurts.

thanks for the help guys,
chris

sicminded

oop signature

cpa7man

iTrader: (2)

Does the engine run a little rough other than the low idle? Is the exhaust note fluctuating like a miss in a piston engine?

sicminded

cpa7man:

the only times i remember it running a little rough is: when you first start the car when mazda has that start up built in where it revs 2.5-3krpm then calms down for the warm up, when it is calming down at the ~1-1.5krpm range it wiggles a bit. when it is idleing low it doesn't idle ruff, a little vibration, not that scary. and when it idles real low sometimes, like when it seems like it is going to die/stall before straightening out again, the engine is ruff.

as far as the engine note it is not bad. um i really haven't had much experience with a misfire in a piston car so i wouldnt really be able to compare it to that. the only thing i hear is a 'putt-putt' after a spirited drive and then parking, at full stop when i rev, when the rpm comes down it makes the sound. but i do not recall that happening recently at all, only once actually when i just got the car. the exhaust is pretty silent. only fluctuating when the rpms are changing, bouncing around.

thanks,
chris

BigIslandSevens

iTrader: (4)

maybe check your boost sensor vaccum line. i just bought one that idled similar to what you described. I plugged it back in and the idle picked up. hope it's that easy!

2-Rotor

First make sure you have had all the recalls done on that car including the upgraded ECU. Since you have an R1 most early R1's were affected by faulty ECM's. You can call the Mazda customer service # (should be in your owners manual) and give them your VIN and they will tell you if it has been done before. If the ECM hasnt been updated then you will get those symtoms especially with the A/C running or when driving and coming to a stop.


---Marc

GoodfellaFD3S

iTrader: (213)

It wouldn't hurt to check (driver's side firewall near the backside of the firewall; the hose plugs in from the underside), but I doubt that's his problem. When that vacuum line comes unplugged, the motor exhibits much more troubling symptoms......

How does the car drive otherwise? Boost good, pull strong?

Tim Benton

iTrader: (1)

as far as the accelerated warm up, start the car in gear and then let off the clutch. It will keep it from jumping up in Rev's and will stay around 1200 or until warmed up. The links to the pics weren't working but none the less I didn't know that the rx-7 had differing face guages in our year model so if I was wrong about that..sorry. Mines like this using your system. First white line is 0, then blank space, next white line is 500 then the hashes start up to 1000.

Not getting an error codes? Jumper the diagnostic and see if the check engine flashes any stored codes. Reaching for straws with that one but ya never know.

Tim

Street King

Be sure it's not in gear when you let the clutch out either.

Tim Benton

iTrader: (1)

tru dat man. Wife might not like it when if the car's halfway in the house.

Tim

dhahlen

iTrader: (5)

My car is idling a bit lower than normal, and the boost gauge should read 15in Hg when idling correct? Well it's bouncing around 10-11inHg and idle is a bit low. ANy ideas?

sicminded

thanks for the replies.

BigIslandSevens: i will try to check for the boost sensor vacuum line. not mechanically inclined and this is my first fd. so i will do my best in this area, heh.

2-Rotor: going to call the number since i still do have the car manual, will check on the recall. i did ask the seller if he did the recalls, but i wasn't aware that the ecu is can be another recall. the seller did mention two recalls that he performed, can't remember what he said now.

GoodfellaFD3S: like i said to BigIslandSevens i will do my best to check the boost snesor vacuum line. even though you described pretty well where the location is, i'm still unfamiliar. would probably leave this area alone since i'm not too familiar with it. so many different things can be wrong. looks like i will just go ahead and bring it to ricks rotary.

the car drives good tho. a little hesitation in the 2.5-3.5k when boostin, probably the common hesitation in some fds. pulls nice tho. then again i can't compare it to any other fds because this my first. but i can feel the turbo kick in cuz this isn't my first turbo car. the only other thing i can think of is when i boost, when i have the windows down, i can here clicking sounds, like two pieces of metal hitting each other. they are not popping sounds, and not loud, i can only here it when the windows are down. have to get that check out as well... heh =\

Tim Benton: thanks for the tip on the start up. website works now because attbi went to comcast today. new site in my signature. they changed all the urls and all. no error codes as in no check engine lights, dont know if there are error codes still stored on it.

thanks for the help all. i hope it is something simple as you guys have mentioned. the only thing going on in my head with this idle problem is an engine rebuild, which i hope its not. i will still probably end up bringing it to ricks, but i am making a list of suggestions/preditions from the feedback i'm getting and will be mentioning it to him.

chris

2-Rotor

Chris here is a link stating all the technical service bulletins for the 1993 model year. The ECU upgrade is mentioned in there along with the symtoms you have previously described. Here is the link: http://www.rx7.org/public/3RD.html

Off the top of my head another big recall that you should get done if you have not already is the fuel line recall. It is mentioned in the link as well.

Another big one is the coolant recall. I will see if i can post the 1-800 # as well.

sicminded

2-Rotor: thanks for the link. guess i will be reading up on it tonite, or when i get a chance, and of course mention it to rick. thanks for the help.

took the car out tonite and it seemed like it is idleing a little better tonite. maybe because it is 60 degrees outside with a cool breeze going on. also maybe because when i was checking out the dashpot. i didn't adjust it at all, just was pressing on it and checking it.

when checking the dashpot i found this plug, was just curious what this is for?



another strange thing i noticed:

i will be referring to this picture to help out what i'm tryin to say.

as you can see i took this picture tonite. good idle, but then again it was a cool 60 degree breeze outside, and my tampering with the dashpot (seems to be working btw).

went out for a ~20 minute drive and only once at a stop light where i reved it dropped down to mark 2 before recuperating back to a little below mark 4 (which the picture is showing). other than this one instance when i rev it would go to mark 3 then recuperate to ~a little below mark 4. not bad...

last friday on a much hotter day, coming home, parked, when i rev it would drop down as low as mark 1 then recuperate. but my idle would be mark 3. now i think that is not normal.

the weirdest thing- tonite when i took this picture i noticed that when i turn off the lights it would idle at mark 3! but when i turn on the parking lights, or headlights, it would idle at ~ alittle below mark 4! why is it when the lights are on it idles higher, in which my case is better? i did this maybe 7 times. lights on mark 4, lights off mark 3, lights on mark 4, lights off mark 3. heh weird.

thanks for looking,
chris

2-Rotor

Chris the car will idle 100 rpm higher with the parking/headlights on because there is more load on the electrical system so it speeds the idle up to increase the charging rate for the demand being used. Your cooling fans will come on a lot sooner if you have the parking lights on as well.

2-Rotor

The plug above the brake booster looks like the connector for cruise control which you do not have because you have an R1.

sicminded

2-Rotor: thanks for the help. didnt know those things.

referring back to the picture i am idleing in mark 4 because my lights were on. but the way it is now, without lights being on, i idle at mark 3. which is not normal right? i ask because i dont want to make a big deal about it if a good working fd does idle at mark 3. what do you guys idle at?

chris

sicminded

bump

referring to the picture a few posts above where do you guys idle at? mark 1, mark 2, mark 3,..?

btw when i was testing my car out the cool night last night. damn this car is fast,.... my first fd.. heh.

chris

2-Rotor

Chris my idle is a little bit above 4 with the parking/headlights on. Headlights/parking lights off it goes a little bit above 3.

Just for the hell of it check to see what your air filter looks like. That might restrict some air flow also make sure all of your intercooler connecter clamps are tight coming off the turbos going to the throttle body.