Technical Questions - New Owner

[Acree]

I just bought a 1991 NA with 155k original miles on it from a forum member here.

There are a couple of basic things I am not too sure about with this car. I also own a 2006 Mistubishi Evo. Here is a link to my dyno thread. We made 615 hp, and will be back soon to push for 660+. This is on a mustang dyno, which would read 10-13% higher on a dynojet.

http://forums.evolutionm.net/evo-dyn...-589ftlbs.html

On that car the stock ECU is fully flashable. There are endless tables that control every engine parameter imaginable. Seeing as my Miata is 15 years older, I'm sure things aren't so simple.

How is idle controlled? Is it simply an idle air adjustment screw on the throttle body?
Can the idle be raised when the AC is on? When the AC kicks on at idle, it currently drops down to 550 rpm which makes it incredibly rough. I need to raise is to at least 800 rpm.
Where can I find miscellaneous parts? I need a new driver side interior door handle, and door handle surround. I need a new rear caliper and a few seals for miscellaneous pieces in the motor. Where do you guys recommend purchasing parts here locally?

I know I will have more questions in the coming weeks, and will post them in this thread. Any input is appreciated!

-Acree

[sammm]

Basic stuff like idle, etc is here...tons of good info.
http://www.miata.net/garage/

Create a WTB thread in the classifieds if you're looking for parts. Mazda-Nissan Heaven in Mansfield is another option.

[trickyrix]

What sammm said, and I'll throw in my $0.02:

For new dealer-only parts, I like Town North Mazda. Haven't been in a while, but Brian is the guy I normally deal with. They're really good about price-matching as long as you throw out something reasonable.

If you can stand to wait, Rosenthal Mazda is a great place to deal with.

Depending on where you're located, Track Dog Racing (trackdog) and Miata Solutions (Rogue) are you go-to repair/performance shops.

On the other hand, these guys will steal your money and feed you one of these.

So there's your local Miata primer... Enjoy!

[Acree]

Where would I be able to buy a brand new HVAC label? I'm talking about the part of the HVAC controls that actually has the writing on it. Mine is incredibly faded.

-Acree

[trickyrix]

I'd check the dealer first.

[jeff_man]

How is idle controlled?Is it simply an idle air adjustment screw on the throttle body?

yes, there is a philips head screw in the throttle body and a throttle stop allen screw, you do a combination of both. will have to adjust them with car fully warmed up then drive it as any adjustment will not show tell after to have driven the car a block or so stop and go.

Can the idle be raised when the AC is on? When the AC kicks on at idle, it currently drops down to 550 rpm which makes it incredibly rough. I need to raise is to at least 800 rpm.

after market ecu or mess with the same idle screws some more.

Where can I find miscellaneous parts? I need a new driver side interior door handle, and door handle surround. I need a new rear caliper and a few seals for miscellaneous pieces in the motor. Where do you guys recommend purchasing parts here locally?

any local shop or mazda salvage will over charge. look for part part out post on different miata forums or you pick it junk yards.

[sammm]

yes, there is a philips head screw in the throttle body and a throttle stop allen screw, you do a combination of both. will have to adjust them with car fully warmed up then drive it as any adjustment will not show tell after to have driven the car a block or so stop and go.

after market ecu or mess with the same idle screws some more.

NA is different than NB.

[Acree]

Had my first crack at getting dirty on the NA today. I had to replace the o-ring on the Cam Angle Sensor. It took about 30 minutes. If I had to do it over again, it would take 10. :P-Acree

[jeff_man]

NA is different than NB.

pretty sure the 97 sitting in my garage has the same screws in about the same places as my 99. throttle bodies are different design and look but same functionality yet i name never messed with the idle on the 97. maybe NA pre 94 are different?

[sammm]

pretty sure the 97 sitting in my garage has the same screws in about the same places as my 99. throttle bodies are different design and look but same functionality yet i name never messed with the idle on the 97. maybe NA pre 94 are different?

Not sure about that, but I was talking about jumping TEN/GND with a paper clip or something when setting the idle. Didn't see you mention that part. I didn't think you could adjust idles on NB at all, didn't know you have a '97 too.

[Electro]

Yep, ambient idle is what you are dealing with. Sammm is on the right track with the TEN/GND. http://www.miata.net/garage/KnowYourCar/S7_Idle.html Beyond that, aftermarket ECU can deal with this easier.

[jeff_man]

Not sure about that, but I was talking about jumping TEN/GND with a paper clip or something when setting the idle. Didn't see you mention that part. I didn't think you could adjust idles on NB at all, didn't know you have a '97 too.

your right, i just never messed with the jumper as i did it by letting more or less air in. having non stock ecus made me forget about the jumper trick. i don't own a 97, there's just one in my garage

[johnwag]

your right, i just never messed with the jumper as i did it by letting more or less air in. having non stock ecus made me forget about the jumper trick. i don't own a 97, there's just one in my garage

when did you get a 97?

[jeff_man]

when did you get a 97?

i forget what year your dust magnet is a 94, 94 to 97 use the same tb. i was on the right thought path.

[Electro]

Acree - Depending on the color you need... I have a driver's armrest door handle and possibly the bucket too for the door handle. It is black and fits 90-97 NAs.

[Acree]

Black would be the color I need sir. Any chance you can email me a pic or two?

Regarding the idle drop, doing the ten-gnc connection didn't seem to do anything. I'm almost positive the ISC Valve is going out. I'm going to test the resistance across it tomorrow to see where it falls. It should be between 11 to 14 ohms. If it reads upwards of 2M ohms or higher, then it has a broken connection. I'll either try to open it up and fix it, or replace it.

On another note, I think I have a pretty bad freon leak. The air was cold as hell on Thursday, and luke warm yesterday.

-Acree

[Rob®]

I should have a spare ISC or two. I honestly don't know if either work, but we can work something out if your specs out of range.

[SirHustlerEsq]

Idle is controlled by a PWM solenoid.
Yes, it can be adjusted through most computers by shortening recovery and or triggering fast-idle (Megasquirt does it this way).

[Electro]

PM sent...

[Acree]

I should have a spare ISC or two. I honestly don't know if either work, but we can work something out if your specs out of range.

I checked it today and sure enough, it registered over 2M ohm. I will need a new ISCV. Please PM with pricing if you have one for sale.

-Acree