BUILT 96' MS3PRO FIRST START-UP [WON'T START]
 

I have a turbo'd 1996 Mazda Miata with a built bottom end motor with 1 mm oversized pistons and a bunch of other minor supporting mods (ARP studs, Cometic Head Gasket, etc.). I am running MS3Pro PNP on the car and the only real difference I have added is that I am running LS2 Ignition Coils fully sequential and I have each signal wire from each ignition coil run straight to the options port on MS3Pro PNP. I loaded the base map and set up all the parameters on the tune and car, the vehicle cranks over and sputters and fires but it never runs on its own. I have fuel pressure, the fuel injectors click, the ignition coils fire, the spark plugs have spark, the motor has compression and pulls vacuum when cranking, the ignition timing is set to 8-12 degrees advances which is very close to the needed 10 degrees (I cannot tell exactly what it is at because it is difficulty to see from just cranking), the mechanical timing of the Crank and Cams is perfect and has been checked over numerous times. It seems like everything individually is working perfect when tested and I asked DIYAUTOTUNE to take a look at my tune and they said everything checked out, sent out my ECU back to them to be tested and everything checked out. The car will crank and sputter but sometimes it will fire and then completely stop cranking (like it fired against the starter) then continue to crank again afterwards. I have no idea what the issue is at this point, I was hoping somebody could help me find the issue. Attached below is my tune on the car.

Attach a log too of it cranking/sputtering.

For now though, try 7 degrees cranking advance, and change your required fuel to 4 or 5, see if that makes a difference. Can't help much until you post a tune, but that's something to try. More fuel and less advance.

Thank you so much for the advice, I will post a datalog tomorrow morning as soon as I can, my battery for drained through the process of cranking over and over so tomorrow when it is charged I will attach it for sure!

Yeah, they won't inject fuel below 8 or 9 volts, so that's something we could see in the log.

My battery never dipped below 11.6 volts but in test mode I could audibly hear each separate fuel injector clicking and each individual LS2 ignition coil firing also. I have had this nearly exact set-up work perfectly with little modification on an MS2PNP but I went to forged internals and MS3Pro PNP and now I am running into these issues sadly!

I have attached a datalog of the car trying to crank over (mind you that my TPS and Oil Temperature Sensor have not been calibrated but I have tried cranking without touching the throttle, modulating the throttle, and wide open throttle with no prevail). I have also sent over an updated tune of the car to make sure it is the most current tune. Along with these two, I have a link to a YouTube video of the car cranking so you can see and hear exactly what is going on.

YOUTUBE VIDEO LINK:
Thank you so much for helping me out it means a lot!

That's kick back, set your cranking advance to 0 and try again, I bet it'll fire up.

I am currently in Southern Illinois for college and the car is sitting in Chicago. I'll drive back first thing tomorrow morning and set the cranking advance to 0. Just a quick question thought as I am not too familiar with the cranking advance, when I was cranking the motor it was reading at 8-10 degrees advanced on the timing light. Does that have any relation to this?

13 is pretty close to 8-10, my guess is it’s not a very accurate way to sync timing

So tomorrow I should go to ignition/wheel decoding settings menu and change my cranking advance from 13 to zero and see if that works? Thanks again for all your help!

+1 on starter kick back, I wouldn't be surprised if your base timing is advanced a bit too if you're getting kickback from 13 degrees of crank advance.

So is the issue essentially that spark is happening way too early to a point where it is fighting the starter motor trying to crank the motor over? Thank you so much for the feedback guys, I seriously appreciate it!

Yeah I’ve always thought of it as trying to fire in reverse, but I might be wrong. Regardless, decreasing cranking advanced seems to help, I’ve even gone negative, but have since found lowering the timing table helps.

Curly and Cpierr03 thank you again for all the help, I will let you know how it works with decreasing the cranking advance and also taking a look at the timing table!

You just need to tune the car. Sounds like it needs more fuel, maybe more air, and still less cranking advance.

You should also really double check your mechanical timing - make sure the crank and cam gears are properly lined up. 0 or retarded crank advance sounds a bit odd to me

Mechanical timing between the Crank and Cams has been checked multiple times by a number of people and it is spot on (Crank Pulley set to TDC, Cylinder #1 is at it's highest point, Cam Gear ticks all line up, 19 belt teeth between each cam gear, and all exhaust and intake lobes face in the complete opposite direction). Everything seems to check out I am just very confused, I just want to at least get it running and driving a little bit so I can break in the new motor before I take it over to a shop to get dyno tuned. Do you guys think my best bet would be to just trailer it over to a shop and have them sort it out since it seems like everything mechanically and electronically is sorted, just needs a clean up on the tuning?

No, I would get it running first. Increase your required fuel by .1-1.0, in steps, to see
if that helps. If not, try adding some throttle to see if it starts.

I’ve definitely tried modulating the throttle a lot (might not show up on the data-logs because I have not yet calibrated my TPS yet). Even with playing with the throttle I haven’t had any prevail. I will definitely try increasing the fueling by 0.1-1.0 to see if it helps out at all. Thank you both for all your help!