Chased

Having trouble getting my miata going again after a head gasket replacement. I verified mechanical timing 3 times. It turns for a little and sounds like it going to catch but doesnt start. I used my timing gun and found out I got no spark on cylinder 1 and 3. Replaced ignition coil, wires, plugs, crank sensor, and cam sensor. I tried loading a few different tunes and the car behaves the same. Still no luck starting. Any and all help appreciated thanks.

Matt Cramer

Why is your MAP sensor reading 150 kPa?

Chased

Thank you sir

I removed the emissions equipment because I didnt think megasquirt used that map sensor. I reinstalled the emissions tonight and took another log. This is on a base map because im afraid one of the old maps might of fried my coilsmap. In despiration I messed up my old maps so much I figure it would be better to start over. I did remember to calibrate coolant, tps ect.

I still need to find out why its reading 150 kpa because I took another log tonight and it still reads high.

That map sensor thats reading 150 kpa is the one attached to the emissions equipment right?

Matt Cramer

That should be the MAP sensor inside the MegaSquirt, unless you are running a MicroSquirt or MS3-Pro. You first need to calibrate the MAP sensor under Tools -> Calibrate MAP / Baro to get it to read right.

Chased

Ok thank you
I have the diy pnp. I calibrated the sensor to my current local kpa. I have no idea how, but when I went to test spark after the map sensor calibration I got spark on all 4 cylinders. Worried I might have a bad connection somewhere.
Anyway went ahead to set ignition timing and she almost started. It seemed like it wasnt spot on until my trigger angle was -27. Going to lower the cranking pulse width tomorrow and hopefully ill be set.

Matt Cramer

Can you also post your MSQ?

Chased

Maybe the timing light didnt fire because the engine was flooded? Anyway I lowered and raised my cranking pulse width but still no start. I left the values where it sounded promising. My car cranks at 180-200 rpm, sounds like it did before but is that a little slow? I have been keeping the car on a battery tender for the last month or so. Right after I built the diiy pnp 6 months ago it fired right up on a base map.

Thanks for your time,
MSQ attached

Matt Cramer

If you can't get the trigger angle set in the -20 to +20 degree range, set Ignition Input Capture to Falling Edge.

Chased

Thanks,
So yesterday I played around with falling edge with various values from -30 to +30. The car sounded like it wanted to start again but it still wouldnt start. Today I was able to have my gf crank the car so I can look at the crank with a timing light instead of adjusting values blindly and sure enough I had no spark on cyl 1 again. Heres the crazy part. I only had spark on cylinder 4. And each time that cylinder would fire the car would knock like it wanted to start. I even checked the timing light on another car and it worked perfect.

Matt Cramer

What sort of coils are you using?

Chased

Its a factory replacement for a 99 miata.
I just got back in town I figure ill try the old coil tomorrow to see if I still only get spark on cyl 4. I guess I could resistance test them both also, as I am hesitant to buy another.