Megasquirt 2 runs, doesn't synch, won't rev past 3k, composite log doesn't look right
#1
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I bought a Megasquirt 2 (V3.0 board) with the intention of modding it for my 1991 Eunos Roadster (Jap Miata) - I built the same board and had success with it about ten year ago for a different car (1992 UK MX5) so I'm not a total noob, although I've still got a lot to learn it seems. My plan is to get this running well N/A using the Denso yellow RX8 injectors that I've got (flow tested to ensure they're genuine) then go turbo.
I've removed the previous owner's dodgy mods, made the DIYAutotune mods, used Reverant's inverted spark mod and it'll start and run. But it won't synch (little red rectangle in the bottom right corner of tuner studio stays red) and runs lumpy - every couple of second the AFRs jump up and the idle won't settle. It also won't rev past about 3,000rpm. I've tried to set the timing, but it jumps from about -10 to +10 according to my timing light, even with the timing set to fixed in Tunerstudio.
Looking at a composite log, the green spikes are irregular and out of synch with the blue square wave (I think one of these is the cam signal and the other is the crank signal but I'm not sure and don't know which is which). I tried adjusting the VR pots R52 and R56 but this doesn't seem to have an effect, other than stopping the car from running at all so I've put these back to fully wound CCW (R52) and 7 turns back from fully wound CCW (R56).
I'm at a loss as to what I need to do to get this running smoothly, please help!
I'll attach my current msq, composite log and general log files, and try to attach a screen grab of the composite log below to save you the time of downloading the log files.
I've removed the previous owner's dodgy mods, made the DIYAutotune mods, used Reverant's inverted spark mod and it'll start and run. But it won't synch (little red rectangle in the bottom right corner of tuner studio stays red) and runs lumpy - every couple of second the AFRs jump up and the idle won't settle. It also won't rev past about 3,000rpm. I've tried to set the timing, but it jumps from about -10 to +10 according to my timing light, even with the timing set to fixed in Tunerstudio.
Looking at a composite log, the green spikes are irregular and out of synch with the blue square wave (I think one of these is the cam signal and the other is the crank signal but I'm not sure and don't know which is which). I tried adjusting the VR pots R52 and R56 but this doesn't seem to have an effect, other than stopping the car from running at all so I've put these back to fully wound CCW (R52) and 7 turns back from fully wound CCW (R56).
I'm at a loss as to what I need to do to get this running smoothly, please help!
I'll attach my current msq, composite log and general log files, and try to attach a screen grab of the composite log below to save you the time of downloading the log files.
![Name: MNqK0q0.png
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Last edited by Androo; 07-06-2020 at 04:20 PM.
#2
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I still need help with this, I haven't managed to make any progress with this at all. I've tried inverting the CMP signal by moving the TSEL jumper from VROUT to VROUTINV (and setting Tunerstudio setting for "Flip Polarity on Cam" to "Inverted" - I think I needed to do this) and again the car wouldn't start. Then I tried changing Input Ignition Capture from Falling Edge to Rising Edge and the car would start, but it was exactly like when the CMP signal was not inverted and ignition input capture was set to Rising Edge. I tried resetting the timing too.
I've never once seen the red synch warning go out. It seems to run smoothly, albeit rich, for a second or two at a time, then the AFR spikes to the high teens and the revs bounce up and down, then it settles for another second or two. I noticed when I was setting the timing with my timing light (with the timing set to fixed) the timing would also jump from one steady position to another when it does this, e.g. it would be at +10deg when steady, then jump forward or back (I forget which) about 10 or 15 degrees during the 'blips'.
Also as I try to build revs, I've noticed it seems to be running really lean - if I run autotune it wants to add lots of fuel to the VE table, but I'm getting a lot of pops and bangs like its putting too much fuel in. I'll attach another MSQ and datalogs, I'd really appreciate some help, I'm close to giving up on Megasquirt and trying a Speeduino but I feel I've put so much time into trying to get this thing working I don't want to give up and sell up just yet. Please help!
I've never once seen the red synch warning go out. It seems to run smoothly, albeit rich, for a second or two at a time, then the AFR spikes to the high teens and the revs bounce up and down, then it settles for another second or two. I noticed when I was setting the timing with my timing light (with the timing set to fixed) the timing would also jump from one steady position to another when it does this, e.g. it would be at +10deg when steady, then jump forward or back (I forget which) about 10 or 15 degrees during the 'blips'.
Also as I try to build revs, I've noticed it seems to be running really lean - if I run autotune it wants to add lots of fuel to the VE table, but I'm getting a lot of pops and bangs like its putting too much fuel in. I'll attach another MSQ and datalogs, I'd really appreciate some help, I'm close to giving up on Megasquirt and trying a Speeduino but I feel I've put so much time into trying to get this thing working I don't want to give up and sell up just yet. Please help!
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