I am running:
MSII v3 board
tried all firmware
car:
'83 280zx turbo
optical crank angle sensor
I am having a problem with a loss of power at 5000rpm and 6000rpm. I have had this problem off and on since I have owned the car, before and after the megasquirt install. Looking at datalogs, I can't see anything that would cause the loss of power (AFR, MAP, dwell, advance...) My guess that the problem lies in the optical crank angle sensor, since this is the only remaining sensor from the stock setup.
Question,
Is there any way to data log the input to the megasquirt from the crank angle sensor? I am curious to see if the signal is degrading at high rpm causing the megasquirt to fowl up. The problem definatly seems ignition related. Thanks!
-jeremy-
dataloging crank angle sensor output?
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jsmcortina
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The MS1/Extra code has a feature to log the tach input,
( http://megasquirt.sourceforge.net/extra/triggerlog.html )
but this doesn't help you with the MS2 at the present time.
This feature will almost certainly make it into MS2/Extra at some point.
James
( http://megasquirt.sourceforge.net/extra/triggerlog.html )
but this doesn't help you with the MS2 at the present time.
This feature will almost certainly make it into MS2/Extra at some point.
James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk
My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
lance,
Thanks for the great replies. I have double checked the timing with a light and it seems to be dead on. To make it easier, I changed all of the values to 15 so that it would remain constant (easier to see fluctuations) and it stayed within a degree or two. The thing is, I can only check that when not driving and I do not experience any percievable problems with the car in neutral. Under acceleration though the problem persists.
I have changed the rev limiter to 7000rpm (redline for this motor) and changed it to fuel cut instead of spark retard.
The trigger wheel has six notches, one for each cylinder and the output on a scope is a really clean square wave pattern. I would check this out again on the scope, but I do not have access to it anymore
Also the scope might not display the problems easily if there is random pulses missing from the signal.
My thoughts are that I might be experiencing some radio interference in the signal wire coming from the distributor. At high load high rpm (when spark is more intense and frequent), the signal becomes messy. This might explain why I am not seeing it in neutral. A datalog of what the megasquirt is seeing might prove to be useful.
The next thought is that the direct coil driver cuircuit only puts out 7amps (I am directly driving the coil through the msII) and this is not enough to provide a hot spark. Has anyone else had any problems with the coil driver not providing enough current to fully saturate their coil? I have messed with dwell and spark duration settings and seemed to have found a happy medium of the settings. .9ms duration, 5ms max dwell Changing the duration either way seemed to decrease performance.
The most frustrating part of the whole bit is that the problem isnt' always there. I had one day where the car pulled very strong clear up to 7000rpm and it felt great. The next day, the car ran as usual with a big power decrease at 6000rpm. I checked the pc board for flux, re-cleaned off what I had missed, reinstalled the firmware, tried different versions, and still have no luck. Otherwise everything is great, but lacking the full power potential of the engine. Thanks for the help, any more would be greatly appriciated. Thanks!
-jeremy-
Thanks for the great replies. I have double checked the timing with a light and it seems to be dead on. To make it easier, I changed all of the values to 15 so that it would remain constant (easier to see fluctuations) and it stayed within a degree or two. The thing is, I can only check that when not driving and I do not experience any percievable problems with the car in neutral. Under acceleration though the problem persists.
I have changed the rev limiter to 7000rpm (redline for this motor) and changed it to fuel cut instead of spark retard.
The trigger wheel has six notches, one for each cylinder and the output on a scope is a really clean square wave pattern. I would check this out again on the scope, but I do not have access to it anymore
Also the scope might not display the problems easily if there is random pulses missing from the signal. My thoughts are that I might be experiencing some radio interference in the signal wire coming from the distributor. At high load high rpm (when spark is more intense and frequent), the signal becomes messy. This might explain why I am not seeing it in neutral. A datalog of what the megasquirt is seeing might prove to be useful.
The next thought is that the direct coil driver cuircuit only puts out 7amps (I am directly driving the coil through the msII) and this is not enough to provide a hot spark. Has anyone else had any problems with the coil driver not providing enough current to fully saturate their coil? I have messed with dwell and spark duration settings and seemed to have found a happy medium of the settings. .9ms duration, 5ms max dwell Changing the duration either way seemed to decrease performance.
The most frustrating part of the whole bit is that the problem isnt' always there. I had one day where the car pulled very strong clear up to 7000rpm and it felt great. The next day, the car ran as usual with a big power decrease at 6000rpm. I checked the pc board for flux, re-cleaned off what I had missed, reinstalled the firmware, tried different versions, and still have no luck. Otherwise everything is great, but lacking the full power potential of the engine. Thanks for the help, any more would be greatly appriciated. Thanks!
-jeremy-