BBR Turbo problem
01-26-2007, 11:07 AM
#1
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BBR Turbo problem
I have a problem!
Background info...
The car is a 1990 Mazda MX-5 (miata). It is a limited edition BBR Turbo.
The BBR Turbo has a piggyback ECU in addition to the Mazda one to adjust fueling and timing as required.
With the Megasquirt plugged in (only the inputs, not controlling injection or timing) as soon as I rev over 2500rpm the engine cuts temporarily until it falls below 2500 again.
I assume that the BBR ECU takes over the timing and fueling above this 2500rpm mark. To me this seems like the piggy back BBR ECU doesn't like sharing the CMP or CKP sensors.
Download datalog200701261509.xls
Background info...
The car is a 1990 Mazda MX-5 (miata). It is a limited edition BBR Turbo.
The BBR Turbo has a piggyback ECU in addition to the Mazda one to adjust fueling and timing as required.
With the Megasquirt plugged in (only the inputs, not controlling injection or timing) as soon as I rev over 2500rpm the engine cuts temporarily until it falls below 2500 again.
I assume that the BBR ECU takes over the timing and fueling above this 2500rpm mark. To me this seems like the piggy back BBR ECU doesn't like sharing the CMP or CKP sensors.
Download datalog200701261509.xls
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01-26-2007, 12:04 PM
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My knowledge is not every good but here's my ideas....
To prevent the engine running wither the fuelling must be cut or the spark must be cut.
If the fuelling was in the log viewer the mixture would be very lean
If the spark was cut the mixture would be very rich.
Looking at 140seconds where the problem starts. I come off the throttle at 143 seconds after its bounced a couple of times. The o2 level remains high up until 144 seconds.
Basicly does this mean as its running rich the problem is with the spark?
To prevent the engine running wither the fuelling must be cut or the spark must be cut.
If the fuelling was in the log viewer the mixture would be very lean
If the spark was cut the mixture would be very rich.
Looking at 140seconds where the problem starts. I come off the throttle at 143 seconds after its bounced a couple of times. The o2 level remains high up until 144 seconds.
Basicly does this mean as its running rich the problem is with the spark?
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01-26-2007, 08:11 PM
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Here's a photo of the underside of my board. The other wires on there are for the USB communication.
http://i100.photobucket.com/albums/m.../CasWiring.jpg
I've use 1W resistors instead of 1/4W ones does that matter?
http://i100.photobucket.com/albums/m.../CasWiring.jpg
I've use 1W resistors instead of 1/4W ones does that matter?
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01-26-2007, 08:18 PM
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Is your CAS wiring the Blue and the Red wires that go from the middle of the pic to the left where they are both covered by the black tape?
In the pic it looks like those two wires join. Is that the case?
The CAS wiring mods are supposed to connect to two wires from the CAS, so there should be two inputs from the DB37 connector (ie there should be two seperate wires going into the DB37 connector on the board).
In the pic it looks like those two wires join. Is that the case?
The CAS wiring mods are supposed to connect to two wires from the CAS, so there should be two inputs from the DB37 connector (ie there should be two seperate wires going into the DB37 connector on the board).
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01-26-2007, 08:47 PM
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Is your CAS wiring the Blue and the Red wires that go from the middle of the pic to the left where they are both covered by the black tape?
In the pic it looks like those two wires join. Is that the case?
The CAS wiring mods are supposed to connect to two wires from the CAS, so there should be two inputs from the DB37 connector (ie there should be two seperate wires going into the DB37 connector on the board).
In the pic it looks like those two wires join. Is that the case?
The CAS wiring mods are supposed to connect to two wires from the CAS, so there should be two inputs from the DB37 connector (ie there should be two seperate wires going into the DB37 connector on the board).
http://i100.photobucket.com/albums/m...CasWiring2.jpg
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01-26-2007, 09:02 PM
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I don't have a pic of the underside of my board handy and I'm not keen to go out to my gar in the rain and remove the hardtop to then remove the side of my roll cage to then access the Megasquirt in the footwell and then pull it apart to get a picture.
Go back to the diyautotune page and follow the written instructions.
"Getting the Tach Input Signal:
Run MSnS-E and the "2nd Trigger" Wheel Decoder option (where the missing tooth on the wheel decoder comes from a second sensor, usually cam position). The CAS has a CMP and CKP signal, so you take the outputs of each and run them into the MegaSquirt. Take the CKP signal (4 holes in the Optical sensor wheel, the "outer" ring of the CAS), and run it to the primary tach input on the MS with a 12v pullup resistor - then you take the inner ring of the CAS (1 hole in the sensor wheel) and run it to the secondary tach input on MS (it's pin 11 on the MS-I cpu) with a 5v pullup resistor.
If you follow my documentation for the mods below you'll externally wire the tach inputs like this:
The Primary tach input (CKP) (Reported to be White on Miatas) is connected to pin 24 on the MegaSquirt's DB37
The Secondary tach input (CMP) (Reported to be Yellow on Miatas) is connected to pin 25 on the MegaSquirt's DB37"
quoted from http://www.diyautotune.com/tech_arti...azda_miata.htm
Go back to the diyautotune page and follow the written instructions.
"Getting the Tach Input Signal:
Run MSnS-E and the "2nd Trigger" Wheel Decoder option (where the missing tooth on the wheel decoder comes from a second sensor, usually cam position). The CAS has a CMP and CKP signal, so you take the outputs of each and run them into the MegaSquirt. Take the CKP signal (4 holes in the Optical sensor wheel, the "outer" ring of the CAS), and run it to the primary tach input on the MS with a 12v pullup resistor - then you take the inner ring of the CAS (1 hole in the sensor wheel) and run it to the secondary tach input on MS (it's pin 11 on the MS-I cpu) with a 5v pullup resistor.
If you follow my documentation for the mods below you'll externally wire the tach inputs like this:
The Primary tach input (CKP) (Reported to be White on Miatas) is connected to pin 24 on the MegaSquirt's DB37
The Secondary tach input (CMP) (Reported to be Yellow on Miatas) is connected to pin 25 on the MegaSquirt's DB37"
quoted from http://www.diyautotune.com/tech_arti...azda_miata.htm
Last edited by Aussie Driver; 01-26-2007 at 09:24 PM.
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01-27-2007, 08:29 AM
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http://www.asbi52.dsl.pipex.com/megasquirt/MS30.jpg
That photo has some extra wires but are you saying that this one isn't right too?
I've wired the ckp and cmp to the correct pins. I dont understand what else needs to be done? The 12V and 5V pull up resistors are one the board. I dont understand what else needs to be done? I'm sure mine is right.
That photo has some extra wires but are you saying that this one isn't right too?
I've wired the ckp and cmp to the correct pins. I dont understand what else needs to be done? The 12V and 5V pull up resistors are one the board. I dont understand what else needs to be done? I'm sure mine is right.
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01-27-2007, 09:18 AM
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http://www.asbi52.dsl.pipex.com/megasquirt/MS30.jpg
That photo has some extra wires but are you saying that this one isn't right too?
I've wired the ckp and cmp to the correct pins. I dont understand what else needs to be done? The 12V and 5V pull up resistors are one the board. I dont understand what else needs to be done? I'm sure mine is right.
That photo has some extra wires but are you saying that this one isn't right too?
I've wired the ckp and cmp to the correct pins. I dont understand what else needs to be done? The 12V and 5V pull up resistors are one the board. I dont understand what else needs to be done? I'm sure mine is right.
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