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MSPNP MSPNP specific Megasquirt related discussion.

delete the AFM

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Old Aug 4, 2009 | 11:00 AM
  #1  
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Default delete the AFM

Hello.
I have a 1.6 miata 97´s (european version) with a 1.6 94 engine (laters engine 1.6 in USA).

Well.
I am investigating about delete the AFM in my car with the PnP MS and the sensor in the intake.

But, refering to wiring i have a terrible question.

there is a light green wire that runs in the AFM and in the MAIN RELAY (FUEL RELAY) (and in the Diagnosis conector) that if the green wire is not conect to ground (with the AFM open) the Relay do not works.

Well, that wire is not conected with the AFM deletion then that wire is not ground, then the Fuel pump should not works. That is a security in the car, for in case of accident, the AFM closes because the engine stops and the Fuel pump stops.

Can any body explain me how is posible that it works????

sanson.

Old Aug 4, 2009 | 11:05 AM
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Originally Posted by sanson
Can any body explain me how is posible that it works????
With the MSPNP, my guess is that they apply switched +12 to the violet wire at position 1C of the ECU, which energizes the second coil inside the relay. (Normally, this coil operates the relay while the starter is engaged, before the AFM terminals have closed) This is why you have to remove the "ST SIGN" fuse when you run a Plug-n-Play MS, to protect the circuit inside the MSPnP which is driving this output.


With a regular (Not PnP) MegaSquirt, you either place a jumper across FP and GND inside the diagnostic connector, or preferably, connect the light green lead at the relay to the "FP" connection at the DB-37.


Also, although your engine may be 1,6L, I find it hard to believe that the wiring is similar to a '90-'93 US-spec car. Does your car have a mechanical airflow meter, (large silver metal box) or a Mass Airflow Sensor (black plastic cylinder)? In the US, all cars after '94 did not have the AFM, and the fuel pump was controlled by the ECU.
Old Aug 4, 2009 | 11:20 AM
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All 1.6 Euro-spec NAs up to 97 have the AFM, not the MAF.

Jim
Old Aug 4, 2009 | 12:27 PM
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Originally Posted by Joe Perez
Also, although your engine may be 1,6L, I find it hard to believe that the wiring is similar to a '90-'93 US-spec car. Does your car have a mechanical airflow meter, (large silver metal box) or a Mass Airflow Sensor (black plastic cylinder)? In the US, all cars after '94 did not have the AFM, and the fuel pump was controlled by the ECU.
The wiring on later 1.6 NAs is almost the exact same as a USDM '90-'93 car, except they relocated one of the pins from the CAS to add an immobilizer on some of them.
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Old Aug 4, 2009 | 12:52 PM
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Wow. Learn something new every day.

Old Aug 4, 2009 | 01:49 PM
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Yes, i have mecanical AFM.
Well really i do not have it now. jejeje

Thanks a lot.

But if a have an accident the fuel pump still goes the fuel to the engine or if one pipe is broken and the engine stops, still throw the GAS to the floor and that is very dangerous.

Sorry for my English

Best Regards.
Old Aug 5, 2009 | 05:28 AM
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Originally Posted by Matt Cramer
The wiring on later 1.6 NAs is almost the exact same as a USDM '90-'93 car, except they relocated one of the pins from the CAS to add an immobilizer on some of them.
the wiring changes too in the inyectors wires, the Euro spec has batch injection. 4 wires, for 4 injectors.
Old Aug 5, 2009 | 09:19 AM
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Ok, I should have said the same as a '93 California spec 1.6 - they have the injectors wired the same way as the Euro 1.6s.
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Old Aug 18, 2009 | 03:26 PM
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Originally Posted by Joe Perez
With the MSPNP, my guess is that they apply switched +12 to the violet wire at position 1C of the ECU, which energizes the second coil inside the relay. (Normally, this coil operates the relay while the starter is engaged, before the AFM terminals have closed) This is why you have to remove the "ST SIGN" fuse when you run a Plug-n-Play MS, to protect the circuit inside the MSPnP which is driving this output.


With a regular (Not PnP) MegaSquirt, you either place a jumper across FP and GND inside the diagnostic connector, or preferably, connect the light green lead at the relay to the "FP" connection at the DB-37.
My fuel pump do not works without the AFM. I have to do the jumper within light green wire and the black one in the diagnosis conector.
How can i know if the firmware in the MSPnP is with or without AFM?? My MSPnP has been tuned by another person and he was the person who delete the AFM.

Is it posible change the tunning parametres MSQ with AFM to a MSQ without AFM?

See you.


See you.
Old Aug 19, 2009 | 10:45 AM
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The only real difference in the with AFM and without AFM settings is the calibration for the IAT sensor.
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Old Aug 19, 2009 | 11:41 AM
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And i supose the Fuel pump.
Old Aug 20, 2009 | 10:31 AM
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Originally Posted by sanson
And i supose the Fuel pump.
No, not really.

I've started to wonder if the "ST SIGN" fuse is labeled something else in Europe, given how often I hear about European users managing to blow the fuel pump drive transistor.
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Old Aug 20, 2009 | 11:00 AM
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My fuel pump works making the jumper. If i remove it, the pump doesn´t work.
I understand you that in Europe the "ST SIGN" fuse has more things under it????
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