Hi everybody,
I have been having a problem that I've been trying to sort out for a few weeks now and am finally admitting that I am stuck and have no idea what's wrong. I have a 1991 Miata with a 2002 VVT engine in it. I rebuilt the engine myself with new pistons, rings and ARP head studs and had each cylinder bored out and honed. The engine is all in the car, wired up, but won't start. It cranks freely and sounds healthy, but I have no spark at any cylinder.

If anyone has any thoughts on why my car might not be starting, I am all ears. Build specifications are below, and Tunerstudio settings are below that.

Build info:
-1991 Miata
-2002 VVT engine (newly rebuilt)
-NA6 5 Speed transmission
-DW600 injectors
-DW200 Fuel Pump
-Speeduino NA6 PnP board w/ Arduino 2560 Mega
-New NGK spark plugs
-New stock ignition coils (2 COP's + 2 wires)
-Cam sensor + crank sensor in place of the NA6 CAS
---Cam and crank sensor are wired according to TheCarPassionChannel's guide on wiring those into the NA6 CAS harness. I have quadruple checked and they are wired correctly. Cam and crank sensor both have 11.7v at the power wire on the connector and 4.7v each at the signal wire when the key is in the "on" position (not cranking). Each of the two plugs is grounded to both the head and the stock ECU ground.

Speeduino settings:
-Base Map for '01-'05 (non MSM)
-Ignition
---Load source ---> MAP
---Wasted Spark
---Crank Advance Angle ---> 10 degrees
---Spark outputs trigger ---> Going Low
---Locked Timing ---> Off
---Use new ignition mode ---> On (https://wiki.speeduino.com/en/decoders/Miata_99)

-Trigger Setup
---Pattern ---> Miata 99-05
---Trigger Angle ---> 10 ATDC
---Trigger Edge ---> Falling (for both primary and secondary sensor)
---Trigger Filter ---> Weak
---Re-sync every cycle ---> Yes

More info:
-Fix crank timing with trigger ---> On (https://wiki.speeduino.com/en/decoders/Miata_99)
-If I crank the engine and pull the spark plugs afterwards, they are wet. So I do have fuel.
-My spark plug tester doesn't register spark at all, no matter what plug I am trying to retrieve spark from
-My VVT solenoid is not plugged into anything at the moment. I have yet to sort out the wiring for it, so I am leaving it unplugged for the time being (until I can start the car)
-I originally had the positive and negative wires flipped on both of my coil plugs. After noticing my coils were getting hot, I fixed the issue. I thought then that maybe I fried my coils by doing that, so I replaced them with new ones.
-I'm reusing the cam sensor that came with the engine
-New crank sensor
-When I crank the engine, Tunerstudio registers that the engine is cranking and that it has sync as well

Again, the issue is no spark. Does anyone have any ideas for me?

 

Check the gap between crank sensor and wheel

 

Since it registers it is cranking, do a composite log and inspect the crank versus cam signals. Post a screenshot of that log here.

Use tunerstudio to do a spark test, if you can.

 

The sensor is gapped to .025 inches, still nothing

 

When I try to perform a composite log, crank and cam signals don't appear in the log. While logging, I can see that the logger registers rpm, pulsewidth, throttle manipulation, and a few other variables, but the tooth logger does not register. In fact, when I try to open the log that I had just taken, Tunerstudio says "Data set empty, can't load it"

Also, my version of Tunerstudio does not have the option for test modes. Perhaps that is just a feature of the "Ultra" version of Tunerstudio, but I only have Tunerstudio MS

 

Buy the $60 version and stop being a cheap ***. The man built a good set of programs and updates them with new functionality for free all the time. Warm up enrichment autotune, VE autotune, and MegaLog Viewer are all included. We'll help you if you invest in the basic tools.

 

In addition to what @sixshooter said, make sure your battery is fully charged. If you're cranking and then leaving the ignition on for a while while you search and fiddle, you're going to get bad results. BTDT. If you don't have a charger, now's a great time to buy one. You'll have many new friends who want to borrow it all the time.

And spend the money on Tuner Studio.

 

I do own a battery charger and have been using it a lot as of late. Any time I have tried to turn over the engine, the battery has been fully charged
Attached is my composite tooth logger screenshot that I just went and got.

Note the error message bottom left

 

Excellent.

Great. Now turn off logging for everything except the crank and cam signals and take another log. I think I see them there, but I can't be sure. If they're there, they don't look like they should.

 

That is to say, based on that image and my poor eyesight, your IAT and CLT look like they're getting readings from the same toothed wheel...

 

Hello did you ever get this resolved?

I am having the same problem. I have a 1990 NA with a 2004 VVT motor controlled by the 89-93 PNP Speeduino.

I have the crank and cam angle sensors from the VVT motor wired in and can see RPM in TunerStudio. However, my tooth and composite logger show nothing except the bar on the left with RPM, air temp, etc.
I can smell fuel after cranking and when I take the spark plugs out they are wet, so I am getting fuel.

I am still attempting to use the stock 1.6 coil pack and wires. But, I am thinking about wiring in the 04 coil packs using the information here: https://www.miataturbo.net/engine-pe...athread-80469/

Let me know if you figured out what your issue was or if you would be willing to share your tune file.

Thank you!