Hi, I'm helping my brother in law get his 1990 1.6L turbo Miata running on his new MSPNP2. I had the car running fine last year on my DIYPNP. Now I can only get it to fire consistently on 3 cylinders. I've swapped igniters, coils, plugs ,wires, uploaded the latest firmware and still get in consistent spark on cylinder 3. Cylinders 1,2, and 4 have great spark. The only other change besides the new ecu is hes now running my old injectors.... they worked fine for me last year. I've checked and cleaned the engine grounds and am lost as to what to do next. Attached is a video of the symptoms showing cylinder 3 compared to cylinder 1 (getting good spark). Also attached is the tune we are currently running.
Thanks,
Mike

 

spark 3 is fired from the same coil, at the same time, as #2.

if everything is good for #2, then swap the plug leads from the 2 and 3 and see if the problem moves to #2.

if so, then it's the plug wire.

 

Plug wires and plugs are brand new, old and new set did this... Two bad sets of wires?

 

Is this using the stock coil or a different setup?

 

Yes, start swapping parts between #2 and #3, if the problem doesn't eventually move to cylinder 2, I'd then swap pistons and bores from #3 to #2. Cause you might not have compression if everything else checks out.

Although I just watched your video. Decent test, and bad compression or not, it wouldn't make the timing light do that. I agree with Braineack, it's either plug wire, or coil. If #2 looks with the above test, it's not wiring or MS.

 

is both #2 and #3 exhibiting the irregular flashing on your timing light?

 

Stock coil and igniter, Ive swapped on a different coil and igniter with the same issues and i put new plug wires on it, Ill swap plug wires when i get home and see if it changes anything. Ill swap wires between 2 and 3 when i get home. Only Cylinder 3 fires intermittently.

 

#2 and #3 are identical paired. so any problem with #3 should also be happening with #2.

switch the position of 2 and 3 on the coilpack itself, and see if #2 now has the issue, could be something messed up with the coil.

 

This is what i thought also which is why i swapped coil packs with a spare i had. Ill swap wires tonight and report back. I guess its possible that both coil packs are messed up, they have been sitting for a while.
Thanks,
Mike