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-   -   Can anyone post a pic of a 94-95.5 coil harness plug? (https://www.miataturbo.net/general-miata-chat-9/can-anyone-post-pic-94-95-5-coil-harness-plug-95447/)

IcantDo55 12-15-2017 10:29 PM

Can anyone post a pic of a 94-95.5 coil harness plug?
 
1 Attachment(s)
Can anyone post a pic of a 94-95.5 coil harness plug?
Is this it? Or is is 4 wire like the 4 pin plug on the coils?
I'm chasing an issue.

shuiend 12-16-2017 08:03 AM

That is only 3 wire. 94-95.5 coil harness is 4 wire.

IcantDo55 12-16-2017 12:45 PM


Originally Posted by shuiend (Post 1457177)
That is only 3 wire. 94-95.5 coil harness is 4 wire.

Than how you explain this. Just got this all stock unmolested 95 that had a 4 pin coil pack. And that 3 wire plug plugged into it. It was built 3/95 so should be early 95 an a 4 wire configuration. Also there is no obd2 port under dash.

The issue is the car starts and runs for 2 seconds than dies. Dash shows no tach signal. I read that the 95 95.5 ECU shut down injectors in 2 seconds if it does not see a tach signal. So that sounds like my issue.
​​​​​Have tried....
2 CAS
2 ECMs
3 coils (2 4 pin and a 3 pin)
Fuel pressure is good and pump has been replaced.
Can be fed with eather and will run for ever on that.

IcantDo55 12-16-2017 12:51 PM

https://cimg8.ibsrv.net/gimg/www.mia...0d8b3185ce.jpg
Built 3/95
Should be obd1 right? Whats cut off in 1995?

curly 12-16-2017 01:08 PM

Quick search gave me this thread:

https://forum.miata.net/vb/showthread.php?t=251759

which says post vin 5130 (so yours) is obd2.

IcantDo55 12-16-2017 01:16 PM


Originally Posted by curly (Post 1457216)
Quick search gave me this thread:

https://forum.miata.net/vb/showthread.php?t=251759

which says post vin 5130 (so yours) is obd2.

Good find.
So who ever before me put wrong coil in it and wrong ECU......maybe.
Hope we on to something.this little issue getting old.
Time to search out a 3 pin coil and a 95.5 97 ECU.
Still does not explain why it has no OBD2 port.....

Braineack 12-16-2017 02:22 PM

96-97 harness is 3-plug.

looks like you have the wrong ECU:



Early 95 BPL9 sub part number BPL9 18 881
95 1/2 BPL9 sub part number BPL9 18 881B

Not much different and hard to tell the difference, but they are not interchangeable. The BPL9 is set up for the 4 wire coil system and gets it's tach signal from the coil packs. The BPL9 B is set up for the 3 wire coil packs and gets it's tach signal from the cam angle sensor.
but if the ecu is driving the tach, that's not the reason it's not running. the car should run without a tach.


read from post #8: https://forum.miata.net/vb/showthread.php?t=372862


I would use diagram here:

https://lh3.googleusercontent.com/Iu...=w1037-h417-no

and figure out every difference between the above and your actually wiring into the ECU -- then we can figure out how to make it work.

IcantDo55 12-16-2017 10:12 PM


Originally Posted by Braineack (Post 1457227)
96-97 harness is 3-plug.

looks like you have the wrong ECU:




but if the ecu is driving the tach, that's not the reason it's not running. the car should run without a tach.


read from post #8: https://forum.miata.net/vb/showthread.php?t=372862


I would use diagram here:

https://lh3.googleusercontent.com/Iu...=w1037-h417-no

and figure out every difference between the above and your actually wiring into the ECU -- then we can figure out how to make it work.


Well good find. Checked and I think I have what is referred to as the OBD 1 1/2 model. 3 wire coil and no OBD2 port. Strange. I checked and its the wrong ECU and the wrong coil.
So looks like I need a BPL9-18-881B, I got a 3 wire coil here already.
Owe ya another beer sir.

Braineack 12-17-2017 10:05 AM

im sure you could re-pin harness for the few wire differences.

IcantDo55 12-31-2017 12:18 PM

Well for all you on the edge of your seats and the future searchers......here is the answer.
The 3/95 is a late model build. It uses what some refer to as a "OBD 1.5" it has one O2 sensor and no OBD2 port yet uses the 3 pin coil pack and a specific ECU with a "B" at the end of model number.
BPL9 sub part number BPL9 18 881B
So swapped in right ECU and right coil pack and it fired right up.

Thanks for all the help.

Anyone looking to buy a RUNNING 95 with 70K on it all stock. Clean.

IcantDo55 12-31-2017 12:18 PM

Well for all you on the edge of your seats and the future searchers......here is the answer.
The 3/95 is a late model build. It uses what some refer to as a "OBD 1.5" it has one O2 sensor and no OBD2 port yet uses the 3 pin coil pack and a specific ECU with a "B" at the end of model number.
BPL9 sub part number BPL9 18 881B
So swapped in right ECU and right coil pack and it fired right up.

Thanks for all the help.

Anyone looking to buy a RUNNING 95 with 70K on it all stock. Clean.


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