MP3 turbo Idle problems.

[1sty]

Alright I have been battling this damn idle issue for severa months now. It all started after my turbo install.

Basicly the cars idle when the clutch is pressed in even while driving slow can fall to almost 0 RPM. If I am going 60 and I press and hold the clutch the RPMs will fall to 0 then return up to 800. If I accelerate then immedatly press in the clutch, the car will stall then a second later restart itself. Also the idle is the worst when the head lights are on. When switched on they can drop the idle to about 200 RPM.

So far I have confirmed there are no intake leaks by spraying choke cleaner on all joints, welds and connections after the maf and all over the intercooler to ensure no leaks. I have released the idle screw so far that it is all but come out.
THe VAC on the car is 20-21 PSI is great according to both Flyin miata and BEGI and rules out the possibility of a vacuum leak.
The idle fuel pressure is 35 PSI which is within range.

HELP!!!!!!!!!!!!!!

 

[promp3]

I would say check your sensors, take it to you dealer and see if its throwing a code, check your maf is pointing the right direction and double check everything, good luck!!

 

[70]

I don't know what to tell you. Mine seems to be doing fine. We backed the idle screw out I think 1/2~1 turn and everything is fine.

I have had the "Miata" drop happen a few times for whatever reason, but no issues. It doesn't happen ona regular basis, so I'm not even sure why that happened. Are all your connections good when you put in the "device"?

 

[1sty]

The MAF is definitly in the right direction, with the turbo kit it can't possibly go backwards.

The cars idle was all over well before the voltage clamp went in. The voltage clamp had no effect on idle. I have checked it several times, after the mistake was found by FM, it should be good.

The only thing that helped was backing out the idle scre about 40 turns. Another few and it will probably come off all together. This helped for about 2 weeks then the car started to overide it and the idle point went lower and lower and the dips got worse again.

The idle is all but back to where it was before I adjusted the idle screw.

 

[LinuxRacr]

I am accually starting to have this issue as well. I backed out the screw once, and it fixed it. I wonder if reseting the ECU would help?

 

[1sty]

Actualy, I think resetting the ECU makes the car more aware of the idle pint and it recalibrates it self to lower it.

After moving out the screw all was fine until I had to do some audio work and disconnected the battery. After that, the idle droop came back in a hurry. I din't hold the brake in or anything but I figured it probably reset itself.

 

[1sty]

If anyone has the shop manual can you tell me if the IAC valve is ontop of the throttle body with the grey clip.

I was told if that was unplugged then the car should stall and if it didn't then it was dead. I pulled the grey clip and nothing happened. It just kept going. I also checked the impedance of the valve and of the grey clip. The grey clip was 11.49 volts dc and the valve was 9.0 volts dc.
I had let the engine warm for about 10 minutes before doing anything but it is 30 degrees out so I don't know if that was long enouhg.

I just need to know if that is the valve before I remove it from the car.

 

[Stou]

Here's some info from the shop manual:

 

[Stou]

Maybe this can help you:

 

[1sty]

Well I took the cylinder part of the IAC valve off and it was covered with black seposites.

I didn't take the peice off the trottle body but I did notice it also had alot of black deposites.

After reinstilation and computer reset the car would not even idle at first and just stalled. I had to hold the gas down and let it rev for 5 minutes then it was able to hold itself. It still idles low and will al but stall if the lights are turned on.

I also check the charging voltage and its at 15 volts, aftermarket alternator, so that OK too.

Thanks Stou

 

[WShade]

Make sure you BOV is working properly. My car was acting the same way when my BOV was sticking. Just a thought

 

[LinuxRacr]

Make sure you BOV is working properly. My car was acting the same way when my BOV was sticking. Just a thought

Yeah, I had to get my BOV replaced too. One of the side ports came out, and was leaking. Another tech told me that one way to fix the idle was to completely remove the screw, clean it, but before doing so set the ten connector to ground to put everything in neutral.

 

[chdesign]

Black deposits could mean oil!!!!!!! Check your turbine wheel to see if it is black anywhere. If so then your crankcase is throwing oil back through and its pushing it through the system and could be clogging things now granted this is not a large amount of oil just what your crankcase spuse out one way to fix it is get a breather filter or to get a catch can.

 

[FuNwaGoN]

Well man I feel for you. I am having all kinds of idle issues as well, as you know. I still can't get the stupid damn dealer to tell me what this switch is that they called me about that is supposed to fix my idle. I have left several messages asking what it is and all they keep saying is bring it in so we can install it. I told them no way in hell are they ever touching my car again. On a related note, I called and spoke to Mazda Consumer Compliance and to Mazda Corporate Customer Service and neither person was able to locate anything about a switch that is out to fix any idle problem on the P5. They said the only fix that is out for the P5 right now is to solve the knocking noise on cold starts. My problems aren't quite as bad as yours but they have gotten that bad before(meaning stalling and cutting out) Now I just get a 2-3 second bog and my lights dim. I know that it may be a long time to wait but the Mazda Corp. Tech is coming to try and fix my car on the 28th. I will post what he finds out then. As far as I am concerned and this is what I told Mazda, He is the only one that will even touch my car. We will see. BTW I have already had the IAC valve replaced in my car and that did not totally solve the problem. Although it was worse before they fixed it. Wish I could help more.

 

[1sty]

Yeah, I had to get my BOV replaced too. One of the side ports came out, and was leaking. Another tech told me that one way to fix the idle was to completely remove the screw, clean it, but before doing so set the ten connector to ground to put everything in neutral.

How do I set the ten pin to ground?

 

[LinuxRacr]

How do I set the ten pin to ground?

Not sure. Not even sure it applys to this car. I will have to research..

 

[1sty]

OK I retested the impedance of the IAC it reads out to 8.6 omha.
I disconnected it and removed it from the car and let it warm up for a half hour.
Now on to check for shorts.
Does anyone know which pin of the ECU is supposed to go to which pin in the harness? The shop manual says to check for shorts and open circuits but if I have the right connections and there are now other resistive element in the path then I should get short circuits.

 

[1sty]

I just rang the wires form the IAC harness to the ECU. I had the brown wire ring directly (.3 ohms) to pin 54 and the grey wire rang directly (.3 ohms) to pin 83.
Neither wire rang to each other or ground.

I assume with this the IAC must either be dead or is working fine and something else must be to blame?

 

[1sty]

After removing, cleaning and reinstalling the MAF and IAC and a computer reset I started the car and to my amazement it actualy started and idled fine. I then removed the hire clip for the IAC and the idle crashed and I quickly replaced it and went for a drive. It acted no differently then it did before. It will still crash if you use the clutch quickly at high speeds and dip severely at lower speeds. After the drive I again removed the IAC cwiring clip and this time the idle did not fall a bit.

So I am back to where I was.

Just two more tid nits. IF I cover the MAF with my hand the car stalls, fast so there are no intake leaks. If I blow into the MAF the car also stall, I have no idea what this means but I figured it couldn't hurt to mention.

 

[70]

Keep us informed...Hopefully they can figure out what the problem is.