More MS un-fun.
#1
More MS un-fun.
http://www.msefi.com/forums/viewtopic.php?t=20871
So, does a miata FP relay have continuous 12V on the coil side?
If so, will this be sufficient to keep this from happening again?
So, does a miata FP relay have continuous 12V on the coil side?
If so, will this be sufficient to keep this from happening again?
Originally Posted by kingofl337
1.6L Fuel Pump Relay
I also had to add a relay to switch the relay for the fuel pump. The megasquirt fires the fuel pump by shorting pin 37 to ground. But, Mazda uses 12v to switch the relay for the fuel pump on the 1.6L. So I spliced into the MAF cable there is one plain black wire in the harness. This is the wire that needs 12v to switch the OEM relay on the 1.6L.
I used an automotive relay to convert the megasquirt fuel pump output to 12v.
Pin 87 was the black - fuel pump relay wire that needs 12v.
Pin 30 and 86 need to be connected to +12v
Pin 85 was connected to PIN37 on the megasquirt.
I also had to add a relay to switch the relay for the fuel pump. The megasquirt fires the fuel pump by shorting pin 37 to ground. But, Mazda uses 12v to switch the relay for the fuel pump on the 1.6L. So I spliced into the MAF cable there is one plain black wire in the harness. This is the wire that needs 12v to switch the OEM relay on the 1.6L.
I used an automotive relay to convert the megasquirt fuel pump output to 12v.
Pin 87 was the black - fuel pump relay wire that needs 12v.
Pin 30 and 86 need to be connected to +12v
Pin 85 was connected to PIN37 on the megasquirt.
#2
Originally Posted by Al Hounos
http://www.msefi.com/forums/viewtopic.php?t=20871
So, does a miata FP relay have continuous 12V on the coil side?
If so, will this be sufficient to keep this from happening again?
So, does a miata FP relay have continuous 12V on the coil side?
If so, will this be sufficient to keep this from happening again?
Do it the easy way. Remove the kickpanel under the steering column and find the circuit opening relay. It has 5 wires coming out of it; blue/black, white/red, violet, black, and light green. Connect MS pin 37 to the light green wire and you're done. This is the same wire as the lt green wire at the MAF and diagnostic port, check for continuity if you're unsure.
The above is based on the 1990 wiring diagrams, since you don't have your year listed.
Last edited by mschlang; 07-24-2006 at 05:32 PM.
#3
It's a 1992. I was under the impression that the stock ECU supplied 12v to the FP, therefore, a ground will not work as a trigger, that's why the relay. In the same post that I quoted, he describes exactly what you do, but only for 1.8 miatas.
https://www.miataturbo.net/forums/showthread.php?t=2217
https://www.miataturbo.net/forums/showthread.php?t=2217
#4
Originally Posted by Al Hounos
It's a 1992. I was under the impression that the stock ECU supplied 12v to the FP, therefore, a ground will not work as a trigger, that's why the relay.
http://www.madracki.com/miata/images/wiring/92diag.pdf
specifically C4 and A22. When the COR is grounded by light green, wht/red is connected to blu/red, giving the FP 12v. At A22, you can see that the FP has 2 wires, blu/red and black.
Check out C7. Here you can see that the AFM turns on the FP by grounding light green to ground. Same thing as a paperclip in the diagnostic port.
Originally Posted by Al Hounos
In the same post that I quoted, he describes exactly what you do, but only for 1.8 miatas.
https://www.miataturbo.net/forums/showthread.php?t=2217
https://www.miataturbo.net/forums/showthread.php?t=2217
Wiring diagrams are you friend
#6
I am glad I waited to hook this up. I was reading the same thread that Al was about the 1.6 FP. When it said find the black wire in the MAF harness and connect it to 12V, I tried that and tripped the breaker. So I temporarily connected the light green wire to ground so that it runs when my key is on. I don't mind wiring a relay, but I just haven't had time. I hadn't made the connection yet that MS pin 37 sends out a ground to fire the pump. That's good news, I will wire that up tonight!
BTW, what does COR stand for?
BTW, what does COR stand for?
#8
Originally Posted by Fulltilt
I am glad I waited to hook this up. I was reading the same thread that Al was about the 1.6 FP. When it said find the black wire in the MAF harness and connect it to 12V, I tried that and tripped the breaker. So I temporarily connected the light green wire to ground so that it runs when my key is on. I don't mind wiring a relay, but I just haven't had time. I hadn't made the connection yet that MS pin 37 sends out a ground to fire the pump. That's good news, I will wire that up tonight!
BTW, what does COR stand for?
BTW, what does COR stand for?
The black wire at the airflow meter is a ground. The problem with leaving the jumper in at the diagnostic connector is that in case of an accident, the FP will continue to run as long as the key is on. Hopefully nothing's burning
#16
Elite Member
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Join Date: Jul 2006
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Hi Al, thanks for reminding me (on miata.net) about this forum. Ive spent a few hours lurking to try to get what I can out of it b4 I start posting noob questions. I would have PM'd you, but it wont let me until I get to 10 posts. I also would like to know if you would be alright with talking to me on the phone sometime for a bit to clear stuff a bit since there is soooo much reading to digest and frustratingly little information.
For those who dont know of me, I am working on squirting a 90' 1.6. I am rebuilding the engine right now and I have a BEGi 1.6 turbo kit equivalant to FM1. I'm really excited to get working on this, but its a bit overwhelming.
Anyway, Ill be hanging around here quite a bit for the next couple months or more
For those who dont know of me, I am working on squirting a 90' 1.6. I am rebuilding the engine right now and I have a BEGi 1.6 turbo kit equivalant to FM1. I'm really excited to get working on this, but its a bit overwhelming.
Anyway, Ill be hanging around here quite a bit for the next couple months or more
#17
I really don't know all that much, but you can learn from what I learned the hard way. Just search for threads I've posted in this forum. the two big things that really held me up should be solved for you. they were the spark side of the resistor confusion, and the low impedance injector interference. You should be able to get your MS running in half the time I did.
have you found the instructions on diyautotune?
have you found the instructions on diyautotune?
#18
My fuel pump runs from MS now. Strange though, when it's cold, the FP runs constantly when the key is on and the engine is not, but when it is warmed up and I turn the key on, it runs for two seconds then turns off like it should. Don't know what that is about, but it's better than key on FP on 100% of the time. Anyone else experience this?
#19
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Join Date: Jul 2006
Location: Central California
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I have found the diyautotune instructions, picked away at parts of the megamanual, and read lots and lots of threads. I am getting a better understanding of things the more i read. I just figure it takes some time. Thanks for the help so far
#20
Originally Posted by Fulltilt
My fuel pump runs from MS now. Strange though, when it's cold, the FP runs constantly when the key is on and the engine is not, but when it is warmed up and I turn the key on, it runs for two seconds then turns off like it should. Don't know what that is about, but it's better than key on FP on 100% of the time. Anyone else experience this?
Did you clean the bottom of your board? The MS should turn you fuel pump on
for 2 seconds and then shut off all the time.