[curving_edge]

Hey to all again! I am still having a idle flux issue over the last couple of months. I have posted about this topic before and am appreciative of all your comments and suggestions BUT have yet to find a solution.

Things I have tried:
-popstoys' cleaning and readjusting of the 'ten pin'
-cleaning and disassembling the throttle body and upper intake plenum
-resetting the car (negative and positive battery cable)
-tune up with ngk plugs and factory wires
-air filter
-fuel filter

I have noticed while cold, the idle flux starts up while stopping or when reving the motor and letting the motor catch reg idle. I have also noticed even while warm, WHEN LIGHTS AND BLOWER MOTOR are on, the revs drop and re-pick up. When I turn the lights off and the power draw is less, the cars idle does not flux.

What do you think? Maybe not a IAC or TPS... maybe a battery or bad alternator?

Please advise me on what to do next....

-Curv

 

[Jspade]

The idle drop when you turn the lights on etc is normal. How much of an idle drop are you talking?

 

[curving_edge]

The idle drop when you turn the lights on etc is normal. How much of an idle drop are you talking?

When driving with lights on coming to a stop, it drops to 400-500 rpms. You can definitely feel the engine starve for a moment and then pick back up. While still and reving the motor up, same symtop occurs.

I was also told a bad crankshaft position sensor could be the problem. Its really weird how out miatae have the same idle flux but is caused by different issues...

Thanks for the input thus far...

 

[curving_edge]

Just replaced the alternater and battery last night. Also reconfigured the idle. Seems to be working better but while the lights on and etc... idle still dips, but not as bad...

Guess I am off to change the IAC! :fp:

edit: had autozone and oreillys test the sytem before replacement, and both said alt and batt were bad.

 

[curving_edge]

I will find a cure to this! But It is kind of weird. The Idle flux only hits hard when the lights and accesseries are on...

I dont understand why a extra power draw would casue the symptoms to get worse but hell, I am going to figure this out. I will report back when I get the IAC cleaned out. If that doesnt work, time to replace it!

What do you guys think of this remedy? Even though its based off the 1.6?

http://www.miata.net/garage/isc.html

 

[corkscrew]

I had the same problem when my idle was ~800 it would dip to about 200rpm. I adjusted it to about 1000rpm at idle and haven't had the problem since.

 

[cmiata]

Have you tried to see if any of your harness ground wires are corroded or not connected properly. On another car I owned (not a miata) I went through a similar issue. I was unable to locate exactly what was going on, but I replaced my battery ground, and added a cheap ground wire kit to my engine, not the kind that has a million wires running off the battery but the type that runs from different spots on your engine and various spots on your harness grounds to new locations. It worked well for my cars idle and I noticed improvement in my headlight brightness and engine response.

 

[curving_edge]

Hey to everyone.

You have probably known that I am one of the few who seek the truth about the idle flux bug. I would like to say; I have found a cure! (For me, that is.)

I have a base 2002 miata with 110k miles. Nothing special, just stock. I have tried cleaning the throttle body individually, cleaning the IAC, cleaning the TPS, cleaning the air intake plenum, plugs, wires, fuel filter, fuel additive, air filter, oil change, checking vacuum leaks, and finally connecting the TEN PIN to ground to adjust idle.

So I started probing miata.net and clubroadster.net for hours to no avail. And I mean HOURS! It was like a guilty obsession. But low and behold, I have fixed the idle dip issue by replacing the IDLE AIR CONTROLL VALVE.

Yes, it’s expensive.
Part - Part Number - Price
Idle Air Control: - BP4W20660 - $240.00
IAC Gasket: - BP2Y13W89 - $20.00

This is the fix for my 2002 Miata. This has been one of the best remedies that I can contribute to our forum. I really hope this helps anyone else trying to solve this issue.

God speed and post up some of your remedies that helped your idle flux issue.

-Curv

 

[meahtah]

^ Wow. good job op. That's awesome to hear. What were the symptoms and how do they differ from a failing O2 sensor?

 

[curving_edge]

^ Wow. good job op. That's awesome to hear. What were the symptoms and how do they differ from a failing O2 sensor?

O2 sensor fail would throw on the a CEL and give bad gas mileage. There might be other symptoms but I don't recall idle flux with that. Maybe like the crank sensor or cam sensor might cause an idle flux as well..?

But good luck and post up your remedy

-curv