Valemiata

(Miata NA equipped with MS3pro PNP, LC-2 Wideband and GM IAT)

Hi guys! I decided to create a new post because I found the cause to the previous problem and it might help someone.
Today I finally had time to test the injectors and discovered that injector C (cylinder 4) does not inject fuel (thank you Curly for telling me to test injectors lol)

I tried doing some tests:
- The injector is working (also tested the resistance in ohms and it is equivalent to the others) the problem lies in the wiring.
- I tried to test the continuity from the car harness and discovered that my miata (na) has sequential injection as standard.

I found the wire (green) that leads to the injector connector and the continuity is there but by testing I discovered that no current is coming from the MS.

rereading the installation manual and reading a bit online I saw that there are actually two jumpers to move (for the OEM sequential injection) but it's not clear to me which ones and where to move them.

Would anyone be kind enough to explain this to me or at least tell me if that's the problem?

Thank you so much.

natewin

Please let us know what year car and which MS3

I believe all NA/NB 1.8 are wired for sequential fuel. There are some 1.6 that are too, if they are California emissions cars.

DIY Autotune has pretty good pictures on their site for jumpers. I can help if you post info.

Can also attach tune and more car specs if you want feedback there.

curly

iTrader: (25)

He's got a 1.6, but in Italy, so I'm guessing they're all "cali" spec over there, which is why I was trying to get him to test the injectors, I suspected it was running on a map assuming batch, when he was sequential.

For clarification valemiata, the Megasquirt does not power the injectors. The injectors are constantly powered on the white/red wire, if any of them don't have +12v, you have a broken splice internal to the harness, or a bad pin at the connector. The ECU pulses the ground, you won't be able to detect it with a multimeter unless it's a fancy one.

Answer natewin's questions and we can help you look at the jumpers.

Valemiata

First of all massive thanks to all the people who helped me solving this issue (in this thread and in the old one).

I succesfully set up the jumpers as the manual said (funny that i didn’t read that in the first place) and now it’s runnin like a damn clock!

now i can just get myself to tune this car and make it perfect!

i’m going to attach some photos of the job before and after (ignore the italian words lol)


Before

After