Idle impossible,solved??
 

Attachment 107777

I cannot make my car idle any lower than 2k. I have adjusted fuel and timing in large and small amounts with no big difference except in afr reading. I'm sure I have a few settings that are incorrect. AFR gauge and tunerstudio match. Attached is my current tune. Anyone interested I helping out a bit?

1995 1.8
WB MTX L
Header, 2-1/4" from header out,high flow cat
ghetto cold air
exhintake

Running in open loop currently

You need to post a log too.

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Here is a short log. I notice that I am getting an incorrect air temp. it says 68 deg. no matter what. I'm not too surprised, directions are somewhat conflicting on tapping into the maf wires. DIY says that I should have a yellow wire and a brown one, or something like that. then I found another write up saying black with red stripe and a ground. this looked like mine so I went with it. both directions had the connection in the same location though..

Log Fail. let me try this again..

Attachment 107828Attachment 107815

Still idling at 2K.
Still not sure why I am not getting an AIT reading. This one seems to be a default, considering that it was 45 deg F. when I took this sample.

-Tuner Noob

Edit- IAT tested bad, purchased a new one and it tested good. plugged it in, no real IAT reading that I believe. re tested and it is bad now. I wired into the maf per the megamanual instructions but something is definitely wrong. The larger red and black wires are the ones I spliced in.

I am having the same issue but on a 90. Any ideas on what the fix is for the high idle

Read the mega manual, figure out that some of it doesnt apply to the newest tunerstudio, Sift through 100's of threads and spend a few weekends banging your forehead against a keyboard. That's the route I'm taking.

Been looking through threads for awhile still have not resolve it. What I do know is I don't have any vacuum leaks and the ice is working.

Ok I can accept that none of the really good guys around here have any interest in another idle issue, especially since I have not made a good impression in the past. what I would really appreciate though, is for someone to look at my IAT wiring and at least help me figure out why I am burning out new sensors instantly.

Thanks

251 views and I cant even get any ridicule???

How did you test the IAT? DMM and pot of boiling water? You should have the correct wires (no. 2 and 3 as seen from wire side), although I have black/blue and red/black (which goes to 2P at the ECU connector, IAT).

I tested the resistance at room temp and get something like 3.5 k or something. Then after I plug it in and run the car, if I test it again I just get an OL. signal. Maybe this isn't the correct way to test? Either way, I never get an actual air temp. Is it my version of tuner studio? The only gauge I have says est. Air temp. What the F does that mean? Why is it an estimation and not actual? Right now the actual air temp IS the same as the estimated air temp, so at least I get to fiddle around with it.

Are you sure you have the IAT wired up properly? Did you test the wires for continuity and see if one is broken somewhere in the line?

Wait, what? Spliced in? Is the stock MAF still in the system and you have the IAT spliced into that circuit?

The IAT replaces that entire part of the system. It should be wired like this.

DIYPNP MegaSquirt installation for the Mazda Miata (scroll down to "Deleting the MAF")

If I'm seeing this correctly, you have two sensors conflicting on the same circuit.

No. The Maf is gone. Just instead of shoving wires into the plug, I soldered them into the wires on the back side. I have looked at that instruction many times. Like I said, they say to connect to wire colors that I do not have. So I just used the same locations. 3&4 I believe.

Well the wire is brand new and only 12" long before it goes to the factory harness for that maf. Not sure what I would be looking for as far as continuity. One should be ground and the other should be what? I'm assuming you are talking about the factory harness?

I would recommend pinning them out to ensure that "3 & 4" are in fact the sensor wires, especially if the colors are not what you expected to find.

General "good engineering practice" is to never assume that because a wire is in the correct location at one end, that it is in the correct location at the other.

The fact that the readings are wrong, and the sensors are failing tells me the sensor is wired wrong.

I feel like such a boner. It doesn't seem like it should be this difficult for me.

When I say continuity, I mean put your DMM on audible and touch one pin to where you have the sensor entering the factory harness, and the other to the appropriate pin on the MS. If you hear a beep, you are safe. If not, your wiring is wrong.

What is continuity?
You might be asking, "What is continuity?" But don't worry, it's quite simple! Continuity means, are two things electrically connected. So if two electronic parts are connected with a wire, they are continuous. If they are connected with cotton string, they are not: while they are connected, the cotton string is not conductive.

You can always use a resistance-tester (ohmmeter) to figure out if something is connected because the resistance of wires is very small, less than 100 ohms, usually. However, continuity testers usually have a piezo buzzer which beeps. This makes them very useful when you want to poke at a circuit and need to focus on where the probes are instead of staring at the meter display.

For some basic circuits you can just look to see where the wires go to determine continuity but it's always wise to use a multimeter. Sometimes wires break or you're tired and can't easily follow all the PCB traces. I use continuity check all the time!

What is it good for?
Continuity is one of the most important tests. Here are some things it is good for

Determine if your soldering is good. If your solder joint it is a cold solder connection it will appear connected but in actually it is not! This can be really frustrating if you are not experienced in visually detecting cold solder joints
Determine if a wire is broken in the middle. Power cords and headphone cables are notorious for breaking inside the shielding, it appears as if the cable is fine but inside the wires have been bent so much they eventually broke.
Making sure something isn't connected. Sometimes a solder joint will short two connections. Or maybe your PCB has mistakes on it and some traces were shorted by accident.
Reverse-engineering or verifying a design back to a schematic
Remember!
You can only test continuity when the device you're testing is not powered. Continuity works by poking a little voltage into the circuit and seeing how much current flows, its perfectly safe for your device but if its powered there is already voltage in the circuit, and you will get incorrect readings

Always test to make sure your meter is working before starting the test by brushing the two tips together, and verifying you hear the beep. Maybe the battery is low or its not in the right mode.

Continuity is non-directional, you can switch probes and it will be the same.

If you are testing two points in a circuit and there is a (big) capacitor between those points you may hear a quick beep and then quiet. That's because the voltage the meter is applying to the circuit is charging up the capacitor and during that time the meter 'thinks' its continuous (essentially)

Small resistors (under 100 ohms or so) and also all inductors will seem like short circuits to a multimeter because they are very much like wires.

Likewise, continuity doesn't mean "short" it just means very very low resistance. For example, if you have a circuit that draws an Amp from a 5V supply, it will appear to be a 5Ω resistor. If you measure that with your meter it will think its a short circuit, but really its just a high-drain circuit.

I am familiar with all of that except for your last paragraph. I did not know that a high draw would look like a short with an ohm meter.

Just checking. You never know someone's electrical experience over the internet.

It still sounds like the wiring is possibly incorrect, or shorting out somewhere.

The car runs great on the stock ecu. Could it if something was broken? This was a braineak built unit, I wouldn't thinking would have any strange wiring.

No no, totally cool of you and someone else that sees this, it might be a big help.

Every wire diagram I find for my ms, refers to a 37 pin connector. mine has two plugs that my factory harness uses. one has 27 (I think) the other one is small and I forget how many it has. are the diagrams combining to two?? this would be strange since they are four inches apart.

What I suggest is looking at the factory wiring diagram for the 95, and finding out which pin on the ECU harness corresponds to the colored wired on the plug where the IAT is spliced into, to verify that you are spliced into the correct wires.

If you don't have them already; this will help you verify exactly what wire on the connector goes to and is used for.

Miata Forumz - Mazda Miata Chat Forums

Going through your posts, picking it apart.

What is Est air temp? I've never seen that on Tunerstudio. Did you right click it and set the gauges to IAT?

Also, did you go to project properties/calibrate sensors/ and calibrate the IAT accordingly?

holy continuity! The pigtail made by the previous ms owner was the turd. I had a fancy delphi plug with the wires just jammed into it. No female wire teminals, just balled up exposed wire. Moving on to the idle adjustment now, should I skip the open loop and go straight for closed?

Thanks guys

Yes I calibrated it, as the gm default. searched through all the gauges, this is the closest thing I could find to intake temp.... est. intake temp sure seems fishy..

I just checked again. I definitely only have the choice of "est. intake air temp".

To help, the link that dieselmiata gave you, look at Pg 8-9 of the PDF file. On Pg 8 the left side is where your harness connects to the ECU (notice how you have 2 "blocks" of numbers 1A, 1B etc... 2A, 2B etc, this corresponds with your 2 connectors) so if you go from that point you can figure out what wire is where (and what colors to look for). Sometimes it helps to print both pages + tape them at the margin with the wires aligned so you can view the circuits. Sorry to be so basic if you know that.

Strange. I'll look at mine when I get home, can;t say I've ever seen EST IAT.

Ha! Its so basic I had never thought of doing that. Way easier than swiveling my head back and forth from the picture to the plug in front of me.

ok, Im getting an Est. air temp that I believe now. still idles like crap. If I use a spark and fuel table that makes sense to me, It idles at 1800K. if ii pull all of the timing out (down to 5degfor a block of cells) it comes down to 800 and sounds like poo poo. shakes really bad. If I remove all of the fuel, i get similar results. If i remove both of them, I end up with a map that looks like none I have ever seen around here. still in open loop, I am convinced that I need to figure this out before going to closed loop settings.

Stubling on a good write up on idle setting, I decided that I needed to start all over with a new base map. noob question- Why does a non turbo base map from diy have map readings to 240kpa????? isnt this a turbo type pressure? if so, how do I re set it going only to say 105KPA, without individually changing every cell? if I use the cell generator, after entering all of the info it requires, I get a whole map of zeros.
In the idle tune instructions, It says to unplug the iac controll and raise the idle back up by turning the idle screw about 1full turn..Ummm, I had to go like 8 turns. something must be wrong here..


Should I still in open loop, have my pwm working at full temp, or should it zero out somewhere before full temp?

Totally discouraged, another free weekend day spent fiddle fucking with a car that still runs like crap.

UPDATE! reloded a base map again, started from the beginning and it idles! seems to run ok but the tune looks really strange.. new tune tomorrow.