Na8 cutting out... Fault codes?

Chicane8 · Postby **Chicane8** » Sat Jan 14, 2017 9:49 pm

Hi guys my little Na 8 has died..stalls and won't start. Cranks over but no go. Left for a day and then it ran around the corner and died again.
Towed home and now trying the LED trick to get error codes? Friend at work made me the LED but on the Internet info is unclear whether a 96 model can be read this way? Something about OBDii ??
The LED flashes but the sequence I'm getting is..
10 11 11 10 10 13 14 10 which doesn't seem to be right. I can't see a 13 code anywhere on charts.
I had a look under the dash for this other OBD2 reader port thing and couldn't see one.
Sorry this is the first time I've ever tried any electronic work, normally spanners only so I'm no Mr Tesla!!

93_Clubman · Postby **93_Clubman** » Sun Jan 15, 2017 10:06 am

From Aug 1995 the JDM NA8 had 16bit ECU & different coils fitted (as opposed to the previous 8 bit ECU). This appeared in the ADM in the 1996 NA8, however ADM didn't get OBDII until 2002 NB8B. Good question about whether the LED flash code test & flash codes of the 8 bit ECU applies to the 16 bit ECU - will have to do a bit of research.
For now, re NA8 cranking, but not starting see following: viewtopic.php?f=29&t=74005
Suggest first thing to do is check for air, fuel & spark to try to narrow it down.

Chicane8 · Postby **Chicane8** » Sun Jan 15, 2017 10:57 am

Yep thanks makes sense, will try to check the basics..will be interesting about the flash codes I suspect it may not work on the 96 model but if you find out give me a hoy
Thanks again

RS2000 · Postby **RS2000** » Sun Jan 15, 2017 11:02 am

Here's an obd-1 test procedure & codes from miata.net that I've used - but no fault 11 & 13 codes shown.
The first flash is an ignition pulse, not a fault, which can confuse readings.

https://www.miata.net/garage/Engine_Diagnostics.html

93_Clubman · Postby **93_Clubman** » Sun Jan 15, 2017 11:28 am

See Caffeine's opening post in following: viewtopic.php?t=67370
He has an early NB8B, so no OBDII port & used last digit from each number to get a 4 digit fault code, which would make your second set of numbers 0340. However, I'd clear your ECU codes by disconnecting the battery & then pumping the brake pedal a few times, then reconnecting battery & taking it for a run to fault codes again, as the earlier set of numbers may have been stored for a while & not apply. Btw, from memory (been years since I used this on my early NA8), no need to make an LED as one of our instrument lights flash as per: https://www.miata.net/garage/faultcodes.html

Chicane8 · Postby **Chicane8** » Sun Jan 15, 2017 3:45 pm

Thanks guys, I was allowing the first flash to go past before reading, so could that mean two codes of 0110 and 0340? If so is there a chart for four digit codes somewhere as I've only seen the two digit charts.
I had recently cleared the computer when I replaced an O2 sensor a week or two ago.. So the codes should be current. I can't really drive it as it won't start at all now?

Chicane8 · Postby **Chicane8** » Sun Jan 15, 2017 4:03 pm

I just found this article on the four digit codes..http://mevowners.proboards.com/thread/5 ... iagnostics
There is mention of a 0110 code for intake air temp
But there isn't a 0340 code so bit confusing...

Chicane8 · Postby **Chicane8** » Sun Jan 15, 2017 4:38 pm

Something else I forgot to mention was when you are turning over trying to start you can hear what sounds like relays clicking on or off from under the dash?

93_Clubman · Postby **93_Clubman** » Mon Jan 16, 2017 10:26 am

Chicane8 wrote:is there a chart for four digit codes somewhere

Yep, in Caffeine's thread above & it includes OBDII code 0340: viewtopic.php?t=67370
Relay clicking you're hearing is most likely the 'Fuel Inj' relay in the engine bay fuse box. It's sometimes also referred to as the main relay or 'EGI' relay on the NB8.

Chicane8 · Postby **Chicane8** » Mon Jan 16, 2017 6:01 pm

Ok that's helpful cheers, with regard to the relays are you saying that's normal maybe due to the no spark issue? Or do you mean the relay could be faulty as well?
Many thanks

93_Clubman · Postby **93_Clubman** » Mon Jan 16, 2017 7:15 pm

Hearing the 'Fuel Inj' relay in the engine bay fuse box click when you turn ignition to on is normal.
First mentioned of no spark, so sounds like you've been doing some testing.

Chicane8 · Postby **Chicane8** » Thu Jan 19, 2017 2:06 pm

Ok so I just replaced the CAS internals with a new part, and no change unfortunately...I was going by the 0430 code as a guide but it seems that isn't the problem. Not sure where to next? Apart from ECU or coil pack I'm out of ideas at the moment...

93_Clubman · Postby **93_Clubman** » Thu Jan 19, 2017 7:08 pm

93_Clubman wrote:For now, re NA8 cranking, but not starting see following: viewtopic.php?f=29&t=74005
Suggest first thing to do is check for air, fuel & spark to try to narrow it down.

chrons_rotary · Postby **chrons_rotary** » Fri Jan 20, 2017 7:14 am

I've had a similar problem before.
When it died, did the tacho and oil pressure gauge drop to zero, even though the engine was still running for a short while?
If so It could be your EFI relay in the engine bay.
Mine had died on me, even though I could hear it clicking, after pulling it apart I found that even though the coil was energized, the contacts were not closing all the way due to the housing being a little melted.
Relay from Mania was ~$35.