Help with building your Speeduino, installing it, getting it to run etc.
By SpeedyMiataVVT
#43146
Hi everyone,
I posted in this forum a few weeks ago with a no-spark issue that I have since solved. I'm now tackling a no-start issue, so I'm starting a new thread.
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, cranks freely, but won't start.

Attached is my current .msq file. It won't let me upload my datalog that I took when cranking, not sure what that's about.

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 NGK Plug wires
-Coil Pack+Ignitor from the '91 chassis
-2002 Cam sensor + crank sensor in place of the NA6 CAS

Speeduino settings:
-Base Map for '01-'05 (non MSM)
-Ignition
---Load source ---> MAP
---Wasted Spark
---Crank Advance Angle ---> 5 degrees
---Spark outputs trigger ---> Going Low
---Locked Timing ---> Off
---Use new ignition mode ---> Off (because I am using NA6 coil pack and igniter, not VVT COP's)

-Trigger Setup
---Pattern ---> Miata 99-05
---Trigger Angle ---> -10* ATDC (aka +10* BTDC)
---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.
-I do get occasional ignition events. I'll hear little pops and bangs as I'm cranking the engine.
-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'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
-Tachometer works

Any help would be greatly appreciated!
Attachments
(58.2 KiB) Downloaded 8 times
By lsdlsd88
#43150
checked with a timing light ?

pretty sure trigger angle should be 0 ?

also use new ignition mode, it has nothing to do with the type of coil.
By pani
#43152
1 have you checked your timing with a timing light?
2 your afr table does not look good specially in the overrun
3 your cold advance pulls 15 degrees timing across the board. Zero it
4 your WUE injects too much fuel at 75 degrees
5 WUE should taper at 100 at lower engine temp ie around 15 degrees lower that the thermostat open temp 180ish
6 its a good idea to put a boost cut in the tune ie 170 would be ok for your 160 maps
7 does it crank freely or does it stumble because of too much fuel

i would check the timing first
By SpeedyMiataVVT
#43164
1. No I have not, my timing light doesn't blink when the engine is cranking. I do have spark though, because it registers with my spark tester
2. Thank you, I've updated the AFR target table and attached the updated .msq file. I also fixed points 3-6 from your reply in the updated .msq file
7. It cranks freely
Attachments
(58.2 KiB) Downloaded 9 times
By pani
#43204
I guess still no start. Your logger looks good except that i see a difference in IAT temp and engine temp. I am at work and can't see the msq right now. Can you get a log when cranking and upload?
By SpeedyMiataVVT
#43223
pani wrote:
Thu May 28, 2020 7:00 am
I guess still no start. Your logger looks good except that i see a difference in IAT temp and engine temp. I am at work and can't see the msq right now. Can you get a log when cranking and upload?
Yep, still no start. When I try to upload a datalog, it gives me an error message saying the file type isn't supported. I will host the file through google instead, here is the link: https://drive.google.com/file/d/1l7CsnZ ... sp=sharing

Let me know if you are able to see it
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