joejoepop

Ok, any miata and or MS experts please chime in.

I've got only plug 1 and 4 firing, and 1 is much brighter than 4. The other coils are producing no spark at all. Tried swapping out the coil pack, no change. So, this car was previously running great. What are the potential culprits here. I believe the ecu does not send individual signals to each coil pack seperately, is this correct? It seems to be the case by looking at the pinout. Does the ignitor send seperate signals to the two packs? Could the CAS have packed it in, or is there a specific wiring issue that seems likely?

Any help trying to diagnose is greatly appreciated.

90 miata, running mspnp2 ecu, variable TPS (Bosch,) GM air temp sensor.

Braineack

iTrader: (62)

was it working previously and now only 1 of the coils is firing?

or are you saying

you just installed a MSPNP2 and now only 1 of the coils is firing?

joejoepop

Nope, it was running fine with the megasquirt MSPNP2, until something must have malfuntioned or died. What I am trying to understand is what could make this happen. Could the megasquirt malfunction in such a way as to only fire one coil, and one of those plugs is firing much better than the other, or could this be ignitor, or CAS?
The timing was set carefully, and everything was functioning great, then something has simply gone wrong and I am asking for help in the diagnosis, as i n, what units could malfunction to cause this?

joejoepop

In the end, it was the igniter, and I went through a couple of them before I abandoned that system all together and went with the trackspeed engineering coil on plug kit, which eliminates the whole igniter and stock coil system.
Ignition