Hello.
I have an Allegro Mazda(Colombia)year 2000,(protege in US)ZM series motor, 1600CC DOHC 36000Kms. When i stop in a trafic ligth or in idle speed de RMP fluctuates between 750 and 550RPM and when i begin to run the car (mechanic gear box)i have to do it slowly because the car hesitates, no problems running, an it seems to get worse when i have the A/C on, the computer scanner does not shows any fault code. I got a new set of spark plugs, wires, replace one coil (distributor less ignition system)put a new air filter, adjust the idle speed with the computer interface,clean the MAF sensor, clean the butterfly valve (intake) i also checked out the fuel filter, air intake hose and air hoses to the sensors for vacuum leaks an so on. The problem continues. I think my idle control valve is one of the step motor type i am not sure, but belive me i am going crazy. Can anyone help me ? because my dealer (the only one in my city) seems to know less than i am.

Regards
LUIS

i did some research on your problem. from what i found out it is the idle silenoid valve. if im not mistaken you either have to replace or clean it. it tends to gather carbon build up. anyways it is worth the try

i agree!! it's the iac"idle air control valve"
or the egr.....i am thinking iac! hook up a scan tool again...and watch you iac data...it the step's or counts are jumping around then you know the iac is having troble geting the idle right...so that could be carbon build up.

The fuel cut off solenoid may be faulty and not allowing the car to idle.

Your carby may be full of shit. Try to clean it out.

Sucking air from the manifold get a spray can of CRC or WD 40 or similar spray around the inlet manifold if revs increase its sucking air. replace the gasket.

all i can tink of.

I'm having a similar problem, but my car starts from cold at 1,500 rpm then comes down to around 900 rpm. The only problem is it takes about 30 minutes to come down and it's not easy to drive with high rpm.

Any advice welcome.

I HAVE A 93 MX3 AND THE IDLE WAS ERACTIC ALSO... IT WASN'T UNTIL I GOT ON THIS MESSAGE BOARD THAT I TRIED TO FIGURE IT OUT FOR MYSELF i HAVE BEEN TO MAZDA DEALERS AND OTHER GARAGES AND THEY ALL SUCK!!! AFTER SPENDING THOUSANDS OF DOLLARS AND MANY DAYS WITHOUT MY CAR...ALL I DID WAS TRY THE INTERNET AND LOW AND BEHOLD I FOUND THIS SIGHT. I THOUGHT I WOULD SPEND A MEASLY $50 BUCKS ON SPARK PLUG WIRES... IT WORKS !!!! MY IDLE IS GREAT NOW AND I CAN EVEN TURN ALL ACCESORIES ON AT THE SAME TIME.... YES FINALLY... SO I SAY TO YOU SPEND $50 AND TRY IT YOU HAVE ABSOLUTLEY NOTHING TO LOSE....


MAXINE

I have a friend who just had simular case, but his was the condenser fan motor-it quit. AC on, the car would almost die at idle, and do fine sometimes. Hope this helps