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The problem did not go away, after I clean the MAF.
PLEASE HELP!!!!

I recorded the issue here. Happens 1st time start in every day when cold. Then it works ok for rest of the day, until next morning cold start.
The engine does fire up and goes to a high 1500 RPM, then dips quickly to 4-500 and then stall. 2nd time will usually succeed, but with the needle fluctuate a couple of time before settling in.

https://www.youtube.com/watch?v=aNig5Sgo2yM

https://www.youtube.com/watch?v=H8ZkGxbOqDI

Hi Tom,
Maybe have a look at your Idle Air Control Valve. There are a few threads on cleaning this out. Mine was pretty gummed up and I had similar issues. I took mine off and flushed it out with carburettor cleaner, let it dry and then reinstalled.

It's function is to allow air to bypass the throttle plate to adjust/control idle, and i believe it can play havoc with idle if it's not moving freely.

The American wrote:Hi Tom,
Maybe have a look at your Idle Air Control Valve. There are a few threads on cleaning this out. Mine was pretty gummed up and I had similar issues. I took mine off and flushed it out with carburettor cleaner, let it dry and then reinstalled.

It's function is to allow air to bypass the throttle plate to adjust/control idle, and i believe it can play havoc with idle if it's not moving freely.

Thank you. I will try to clean this sometimes this week. So I just search Idle Air Control Valve, I should find instructions? Because I don't know where it is and how to yet just yet. The fun of DIY and learning.

Hi Tom,

on your car should should find it attached to the underside/front of the throttle body - google IACV Mx5 NB which will give you a picture to know what you're looking for. It's not hard to remove - a few bolts and a plug.

My SP had the same symptoms and I could never solve it. After my battery failed and I replaced it, I haven't had the problem since.

Thank you for all the help and advice. I cleaned and checked every possible sensor and valves. Took it to MX5 PLUS for checking also. But still here.

Been suggested it could be a tune issue and common with aftermarket car (well SP is aftermarket to an extent). They told me that timk's car here, usually needs 4 times turning the key before starting. So it is normal.

I am visiting Chiptorque this week for a tune and I have been advised to ask Lachlan to check for possible solution.

Given BULLITT's experience above, have you checked & cleaned the battery terminals and earth?

^+1 re check & clean of battery terminals & earth strap connections, & test (& replacement if necessary) of battery.
Also FWIW, years ago there was also a poor batch of Fuel Inj / EFI / EGI relays (big green relay in the engine bay fuse box of the NB8B) fitted to the MX5 of the day, which caused a cold start problem requiring repeated starting attempts.

My car was mis-firing intermittently. 2 cylinders not firing. Apparently the coils were too old and breaking down.

I bought new no-name brand coils (COPS) and leads from a guy on eBay.

Best $100 I've spent.

Much better than spending $800 to get someone else to do it.

They may not last as long as Mazda originals, but at least I've done a $100 fix and know what caused the problem.

I got the part number from Arlington Mazda website.

Here's the eBay item (no affiliation) - http://www.ebay.com.au/itm/201477878269 ... EBIDX%3AIT

Cheers!

Thank you guys for all the input. The battery terminal cleaning did not help.
The car definitely is not misfiring, by the sound from engine bay and exhaust. But I might check the coil anyway.

I realized the 2001+ NB8B does not have standard ignition wires like the earlier cars, but lots of little wires on top. Any idea how they work, if any different?

Its just SPs. They are much like an aftermarket ECU equipped car except you cant take them back and get them tuned up when they need it.

Id say its normal and just ignore it.

Dann