RB20DET ecu question

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dynotuner
 

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RB20DET ecu question

Post by dynotuner »

Hello,
I have a 23710-04U12 ecu going into a R33 RB25det series 1.
I have flashed the feature pack ENT for RB25 on it.
I have no output from ignition cyl 5 on pin 2 to power transisitor.
Opened up ECU and found a burnt resistor and 3 others out of spec. Replaced the resistors and still no output.
I think I need to replace IC14 ignition control on the board, however the only other ecu I have is the original 23710- 21U00 from R33.
Will one of those work in the 23710-04U12?
dynotuner
 

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Re: RB20DET ecu question

Post by dynotuner »

I just desoldered IC21 out of R33 23710-21U00 ecu and installed into R32 04U12 ecu. It worked! All 6 cylinders are firing from ecu.

Now that it has ignition, I have another issue.
The engine is filling with fuel, so much that its dripping out of exhaust.
Engine will briefly start roughly, but it is actually hydrolocking on cranking sometimes.
Its a log style intake manifold with top feed 9 ohm new Injector Dynamics 1050cc. Already changed them out once with new ones. same result.
Fuel pressure at 37 psi. The K constant at 322 with Z32 MAF and TIM at 100. Reduced cranking pulse very low.
I am showing 3ms pulsewidth cranking in Nistune.
No intake hoses are connected to potential fuel sources like carbon caniter or fuel tank. Fuel pressure Reg. vacuum hose is dry.
dynotuner
 

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Re: RB20DET ecu question

Post by dynotuner »

Update: cylinders 4,5 and 6 are filling with fuel. Have the plugs out and after cranking with fuel pressure the back 3 cylinders are wet, front 3 dry.
Checked the injector firing on rear cylinder. There is an appox. 15ms firing of injector after I stopped cranking engine. This does not show up on cyl. 1,2,3. Strange part is that injector 1,3,5 are fired together and 2,4,6 are fired together. Its getting wacky on this car.
Matt
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Re: RB20DET ecu question

Post by Matt »

Okay this sounds like a bad ECU initially

So you replaced the ceramic ignition board (which is the usually the first thing which goes to toast when the coil drivers are overdriven)

So now running ID1050s and the TIM seems to be low enough for those injectors

If you have 4,5,6 filling with fuel, but 1,2,3 are fine, I think you have injector plugs around the wrong way maybe? And also the driver in this ECU is also toast and shorted (running the fuel injectors open)

Remove and replace the driver. Check the wiring output for 1,3,5 and 2,4,6
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