ECU fuse keeps blowing on track

[moo moo nel]

Has anyone experienced this before...

I was in WP today.

Car was running fine until...
in the 5th lap of the 2nd session, just before Turn 2, the car shut down itself all of sudden. Engine stopped, no power steering no nothing. Car still got electricity, just couldn't start the engine.

Towed my car back to the shelter. Rang up a few people seeking help. My mechanics told me to check the fuses... so I checked them one by one...

Found the Engine Management (E/M) fuse was blown. Replaced it with a spare 15A. Car started again immediately...

So I went out again, but this time... couldnt even complete a lap... at Turn 10... the car stalled again

Open the fuse box, the fuse I 've just replaced 5mins ago...blown

Managed to pull out another 15A from somewhere and replace the blown one. Car started once again. But I decided to call it a day and head back to Sydney. On the way home I bought more spare fuses just in case.

Nothing happened on the way back, I was doing 90km/h all the way though. Straight to my mechanics, nothing loose, nothing damaged, nothing wrong with VTEC.

FYI I am running PowerFC....been using it for 1yr...nothing wrong before
What do you guys think?

[bennjamin]

try running the standard ECU in similar circumstances. Bet it dont blow.
OBviously something is overloading the fuse....

[moo moo nel]

so you reckon it's the powerfc itself?

[CRXer]

could be quite a few things,

bad component in the pfc
hot joint in the ecu power circuit wiring somewhere
main relay contacts going bad
1 or more injectors overloading the circuit
O2 heater overloading
idle valve overloading

[Benson]

check all grounding points

[ECU-MAN]

the only thing I can think of is , on a track your injectors and coil will be working at almost 90% to 100% duty, the extra power comsumption could be blowing fuses if the ECU is drawing more curent to power them.

[JasonGilholme]

only 15 amps for the ECU fuse??

Is that right? what do EGs/EKs run?? i thought it was 30 amp

[Chi]

It's a blue 15amp fuse.

[moo moo nel]

thanks for the inputs guys

the only thing I can think of is , on a track your injectors and coil will be working at almost 90% to 100% duty, the extra power comsumption could be blowing fuses if the ECU is drawing more curent to power them.

I've been running the same setup for more than 10 track days. Does that mean my ECU faulty all of sudden?

[ECU-MAN]

I see, you have done that before with the exsisting setup.


I would do a current draw test.
first at the ECU to see what its drawing,
then between then coil and ECU
then between then injectors and ECU

also test the current draw between the fuel pump relay and the ECU. should be very minimal

visually inspect all your wiring for rubbing, look for any worn wires that may be rubbing against any metal parts causing shorts.