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The mkiv Supra Owners Club

How does a FCD work?


how_supra
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You need one to prevent the ECU from shutting down the fuel supply if the ECU 'sees' too much boost than Toyota intended.

 

It works by monitoring the signal, (voltage), sent by the MAP sensor, (Manifold Absolute Pressure, or pressure sensor for short). As a rough guide, 1 bar of boost equates to roughly 4.5 volts, so the FCD, (Fuel Cut Defender), allows all the correct voltages to get sent to the ECU, but when it gets to about 4.4volts, it then clamps that signal so that the ECU always 'thinks' you're running standard boost pressures.

 

Does that make sense?

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FC is caused by the ECU seeing a certain voltage from the MAP sensor.

This voltage is created by boost pressure. Once you hit a high enough boost pressure the voltage being received by the ECU tells the ECU it's overboosting and Fuel Cut is initiated.

 

An FCD stops the voltage hitting the FC limit. So the ECU never gets the voltage needed to initiate Fuel Cut.

 

EDIT - Obviously I took too long writing that! :)

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Well, you never know. It might come in handy some day... :whistle:

 

 

Sorry, that's not funny at all. How's you car coming on now? - I haven't been on here for ages so I may have missed you getting it fixed.

 

 

No it is funny, and it was really careless, and to this day I can't think why I didn't check it more regularly. I am now checking the oil every two days!!

 

I finally got the car back on Tuesday, after 5 weeks and 3 weeks of nagging the garage............oh and a hhhhhhhuuuuuuuuugggggggeeee bill. :looney:

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