mirotech question

[ryguy86]

Hey guys..

i have a microtech lt10.

On the loom for the ecu there is a red wire that is the power for the loom.. it has a fuse on it and goes to 12v power.

anyway.. for some reason.. the fuses that i put in there just keep popping. and i dont know why.. even if they loom is not connected to the ecu.. i gues thats good because i know the ecu is okay..

im wondering.. where and what could cause this??? is it too much power?? its only started to do it after months of sucessful use. or is it possible for another wire in the loom to be earthing out ???


any ideas?


cheers.

Ry.

[Cuzzo]

Good chance that if it was working before fine and now its not that it will be a wiring issue.

You could always try the ecu in someone elses car to see if it powers up (or corse dont start it)

Or you could send it to microtech for testing but possibly at a cost.

[Norbie]

So the fuse pops even when the ECU is unplugged? Must be a short circuit somewhere between the fuse and the ECU; check your wiring for damage.

[Forcefed6]

Definitely a short circuit. That red wire splice of to run battery power to the injectors.

With computer unplugged, get a multimeter, and check continuity to see if the red wire is now connected to earth. This should be the case, as there is a dead short somewhere.

Unplug injectors, and try this again. Completely check loom between the battery and the ecu, then to the injectors as well.

[RT40Corona4AGTE]

hmmm could have a dicky injector by the sounds of it?

[Jzxbenno]

I had a similar problem with my lt10s but it was related to the x6 coil controller thingo it had a power wire that had been slightly stripped and was arcing out against the body/head and was feeding back somehow but was blowing the fuse anyways fixed and problem went thats my two cents worth hope it helps

[RT40Corona4AGTE]

ryguy86 - have you had any luck with this problem?

[ryguy86]

ryguy86 - have you had any luck with this problem?

Hey Guys@

Thanks for that ! I will be checking all of these things very shortly. we've had a mad heatwave here in SA so its really hard to get out in the shed over the past 4 days.

Yes the fuses' pop even with the ecu is not plugged in.

i will be checking the power from the loom to the injectors and also to the x4 box.

_______________________________

im still lost has to how it could be injector related?

[RT40Corona4AGTE]

let us know how you go.

[ryguy86]

dont worry i will.

I have printed out this thread and i will be working on it all this weekend!

[DeftAnesthetik]

im not a "master of circuits" by any means but from what i know, in order for current to be passing through the fuse the short would have to be AFTER the fuse on the power line as electricity will always take the shorter path??... just thinking out loud here... i would be more inclined to examine the actual fuse holder and everything after it to find the problem.

[ryguy86]

okay.. so the update to this one.. i had a 20 amp fuse on the power to the ecu.. I had a 20amp fuse powering 3x 10am mini relays fo the coils, and fuel pump etc.. so i took all of those fuses out of the equasion and whammy.. the car started no worries.. so i cant figure out why the fuse was blowing the first place..

i still have to test the running under load as last time i could replace the fuse to the ecu and it would run on idle .. but if i drove the car.. and took it up to the top of 2nd gear.. it would then blow..

so im not too sure why it did it.. i have a feeling it may be supercharger related.. some how.. so im going to replace all the fuses with 30 ampers.. and clean up everything.. put it under load and see what happends.. if she runs.. then ill be out drifting saturday night! yeah!

[Forcefed6]

The fuel pump should be wired on a completely separate fuse all by it self.

It might idle, but as you drive, with the combination of the coils, and the fuel pump, it all draws more current as you put load on them,

So the thick red wire to the ECU should have a 15 amp fuse.
Contrary to what the wiring diagrams say, give the fuel pump, a separate fuse (20 amp) not running in series to the ECU fuse, and the coils and supercharger a separate fuse (15 or 20 amp), and you should be fine.

[ryguy86]

yeah

that i think was my issue...

only 1 fuse for the coils and the fuel pumps. and a 20amp at that. so ill bang a30 in there for each relay i have.

[Nilezy]

I wouldn't suggest putting in bigger fuses, unless your sure that is the right current amount for the circuit.

ie, putting a 30 amp fuse in that doesn't blow when a 20 amp does, mean you have a problem, or you need to assess the maximum current the circuit will draw at normal operation. Remember the fuse is there to protect equipment, and stop hazard like shorts and fires from happening.

The suggestion of running the pump on a separate circuit with its own fuse is how it should have been installed. I'd even put the supercharger clutch on a separate circuit with its own fuse, rated for the current draw of the clutch.

Cheers,
Nilezy