zmarko

And before you guys ask, YES I searched. lol. None of the found threads had a problem like mine (so it seems).

Anyway, here's what the car is doing. This happens during normal driving. What happens is when I come to a stop at a stop light, I will press the clutch in, and put it in gear. Only with the car IN GEAR with the clutch pressed, the car's idle hunts and once in a while will stall. This happens during normal operating temps (not sure about non-normal operating temps cause I don't drive the car until it's warmed up properly). The car idles fine sitting at a light with the car in neutral without the clutch depressed, and also in neutral with the clutch depressed. The only time the idle "hunts" and sometimes stalls, is if it's IN GEAR with the clutch depressed.


Any ideas? I was thinking possibly an ECU problem, or a clutch issue, but am really not sure about any of this. Just seems weird that it only happens when it's in gear.



Mods in sig.

EFS.O

Is the ac on when it is happening?If yes,then its the ecu.There is a TSB about that....

Str8Down

Tell me more about this ECU prob. My car hunts like crazy with the AC on.

EFS.O

From http://www.rx7.org/public/3RD.html :

12. ENGINE STALLS DURING WARM-UP / IDLE FLUCTUATION
Service bulletin #032/92, Category F, issued 12/23/92
Applies to 1993 RX-7 5-spd models with VIN of JM1FD3312P0208703 or
lower produced through July 2, 1992. Applies to 1993 RX-7
automatics with VIN of JM1FD331XP0210513 or lower produced through
September. 30, 1992.

Some 1993 RX-7 vehicles may experience stalling during
deceleration with the throttle released approaching a stop. This
occurs during initial warm-up and, sometimes after the car has
reached operating temperature. Also, when idling with the A/C on,
engine speed decreases as the A/C compressor engages
and idle fluctuation may occur. The ECU has been modified as a
countermeasure. The modified ECU is designed to:
1. Make air/fuel ratio adjustments to maintain stable idle at all
temperatures
2. Turn off the A/C compressor when the clutch pedal is depressed
or when the accelerator pedal is released.

(WARNING from DZ: The following parts may have been superseded by
a more recent TSB. Have your Mazda dealer check their own TSB
list which should be more up to date.)

Replace ECU under warranty with following part:
N3A1 18 881R ECU (Federal 5-speed)
N3A2 18 881R ECU (Federal Automatic Transmission)
N3A3 18 881R ECU (California 5-speed)
N3A4 18 881R ECU (California Automatic Transmission)
----------------------------------------------------------


This is exactly what's happening with my car.Not sure about your's thought...

Str8Down

Hmmm, I have a 94

tkuwaha

iTrader: (18)

Faulty clutch switch(located right above the clutch pedal) caused hunting idle on my car. I took it apart and cleaned the contacts inside. Maybe worth taking a look at.

zmarko

At first I thought the problem was happening with either the AC on or off. But while driving today, it appears that it does only happen with the AC on. I'm going to contact Mazda today about the TSB. Excuse my ignorance here, but is a TSB a recall? Thanks for the info, I really appreciate it.

rynberg

clutch switch

If your idle is low and hunting with the A/C on whether you are in gear or not, your Idle Speed Control solenoid may be bad.

txturbogs

You just solved my problem. My idle drops and the engine stalls when I turn the AC on, never when idling with the AC in off position.

zmarko

Well, I just got back from Mazda, went down there to see if there were any open recalls on my car. There is one on the brake vacuum hose line, but she said not on the ECU. So either it's A) not a recall and it's just merely a TSB, or B) them not wanting to cover it as a recall when it really is.

Anyone know if it actually is a recall? Thanks for all the help.

rynberg

It's not a recall, you can't get it fixed for free.

zmarko

OK, cool. Not a huge deal, just wanted to make sure I didn't pay for something that I didn't have to.

spurvo

question for you zmarko: is your idle hunting with any electrical loads on, like the lights, or the blower fan above 2? Or will it hunt when you put it in gear without loads? I'm having the same symptoms, but ONLY when I have an electrical load on. I have a ost on it in the advanced section, but wanted to ***** a little here if'n I can

tcb100

clutch switch and real cheap (under $10?) and 5 minutes to install.

zmarko

I'll head out and try that today. I always have my parking lights on, as the previous owner had the A/F gauge hooked up to only work when the lights are on (haven't had a chance to re-wire yet). I'll try it both with the lights and A/C off as well and see what I come up with.

zmarko

If it's the clutch switch, wouldn't it do it anytime the clutch is depressed? Not only when the car is actually in gear?