H_ATASSI

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.

curly

iTrader: (25)

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.

H_ATASSI

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!

curly

iTrader: (25)

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

H_ATASSI

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!

H_ATASSI

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!

curly

iTrader: (25)

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

H_ATASSI

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?

curly

iTrader: (25)

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

H_ATASSI

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!

cpierr03

+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.

H_ATASSI

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!

curly

iTrader: (25)

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.

H_ATASSI

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!

H_ATASSI

I swapped in a brand new Optima 34/78 Battery into the car fully charged on a battery tender. I cranked the motor over with the injectors all unplugged and a timing light on the ignition coil for cylinder number one. The timing read at just a little shy of 10 degree advanced. Tried to start the car with the new battery and still the same issue (seems like it is fighting itself, as shown in the YouTube video I had sent earlier in our email chain). I had asked a few tuners to take a look at my video, current tune, and datalog and they advised me to try and change my Crank Advance from 13 degrees to anywhere near or around 0 degrees. Before I did that, with the new battery I tested each individual cylinder's ability to produce spark. I removed the spark plugs from the cylinder head and grounded them on my valve cover. Testing each ignition coil in the CAN-BUS test modes option in TunerStudio I was able to get a constant and strong spark from each coil. Along with that I tested the fuel injectors and was able to get a strong click from each injector. So far at this point I know that I have a strong battery in the car, I definitely have a strong spark in the car, my fuel injectors are working, and I have a strong and constant fuel pressure of 43 psi. Moving on I once again moved the valve cover and assessed my mechanical timing between the crankshaft and camshafts and it is 100% spot on and confirmed by a number of people to ensure I had multiple eyes on it. I compression tested the brand new motor to ensure it was healthy and everything came out great especially for brand new rings and being fairly cold and never heat cycled. Now that I have checked everything and it all seems to be well in spec, I changed my cranking advance value to 0 degrees in TunerStudio and with a lot of struggling it seemed to barely fire over on one or maybe two cylinders while the rest either were not firing at all or were creating a very very loud backfire. Unfortunately I was not datalogging that exact event but I ended up turning it all off and trying it again but to my luck it would no longer fire over but I could definitely hear it trying to. It no longer would suddenly stop and fire against the starter. Attached below is a video of me cranking the motor over at 0 degrees advanced, along with the current tune on the car, and a YouTube video link to my published video of the car trying to start. If the battery for being brand new seems a little low, I took the datalog after trying to crank it over for numerous amounts of times, but the battery voltage never seemed to drop anywhere below 9-9.5 volts. Please let me know what you think my next step should be, I am fairly certain that the issue is related to timing or ignition. FYI I pulled the out plugs from trying to originally fire it over and the first two spark plugs were covered in black soot, the last two seemed much cleaner (especially the fourth which seemed to look like a normal spark plug from a running car with not too many miles on it). Thanks again for all your help.

YOUTUBE VIDEO LINK TO NEW VIDEO:

You Tube

curly

iTrader: (25)

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

cpierr03

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

H_ATASSI

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?

curly

iTrader: (25)

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.

H_ATASSI

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!