Why does my 1g keep blowing ignition fuses..

[Stomps]

Ok, recently installed a 1ggte into my z10.. had fuel pump issues so we set the fuel pump up to run off a relay from ignition..

Input is the power from my amp..
Earth is bolted to the car.. (good earth)
Output goes to the fuel pump
Trigger is via a wire from the ignition barrel.. Connected to "on" position.. when i turn it to "on" you can hear the fuel pump going..

Basically what happens is whenever i give it heaps, ie.. foot to the floor, it cuts revs for a sec, then backfires then usually blows an ignition fuse.. This only happens when i give it heaps, if i drive around on low boost or dont floor it it does not happen..

What could be causing this?
Could it be coz my power is from my amp?
Would it be better to run a separate cable from the battery?

Thanks..

Stomps

[JustCallMeOrlando]

Why didn't you just wire it up properly? Run a wire from the ECU FPR output to the factory circuit opening relay and use the factory wiring?

[brett_celicacoupe]

maybe they wired the injector bank through the IGN barrel circuit as well. didnt a forum member wire it?

its a big thick black wire for memory.


could explain because as the duty cycle goes up, the current drain through the injector circuit would also rise. as soon as it exceeds the fuse rating, it blows

??

[JustCallMeOrlando]

Valid point, where is the power for the injectors coming from?

[Stomps]

OK, main answer to all the questions is i dont know, i make no secret of not knowing SFA about wiring.. I didnt wire it up, it was a combined effort, all i did is wire the fuel pump off a relay as described before..

As far as wiring it off the ecu, i dont know which wire does what etc..

if anyone wants to have a look at it and sort it out properly im happy to pay em to do it..

Anyway more news..

It dosent happen in neutral, only under load, also i just discovered that there is no fuel pump resistor installed.. could this do it?

Stomps

[japlish]

it doesn't do it under load because the pump isn't working that hard,
you should try this...

i forgot what the numbers are on the relay but just ask the guy at the shop.

i did it to my own car and i SUCK at wiring

[Stomps]

it doesn't do it under load because the pump isn't working that hard

it only happens under load.

Stomps

[EldarO]

stomps, it was a typo, he meant "it doesnt do it when not under load because pump isnt working as hard"

makes a valid point though, i had no idea you ran a relay to the fuel pump!

take the wire from"on" at the ignition barrel, run it over to your ecu.

take the cover of your ecu off and look for the pin "FPR" connect to that instead.

Elmo.

[Stomps]

cool, ill try that..

Cheers

Stomps

[wilbo666]

Do it how JCMO suggested.

Tis safe, easy and should work

Cheers
Wilbo

[JustCallMeOrlando]

And it's "the way".

[Stomps]

I think the reason why we didnt do it that way in the first place was that we couldnt find the wiring for it.. We couldnt find where the wiring to the fuel pump was near the computer..

Will it be the same if i just take the wire from the the ignition and run it to the computer FPR? will that do the same thing as using the factory wiring?

Stomps

[JustCallMeOrlando]

No. You need to find the trigger wire at the ECU. It will earth when it's on, putting +12v to it would be bad mkay.

[Stomps]

i meant disconnect it from the ignition and connect it to the computer...

Not connect from ignition to computer..

Basically i would be using the plug on the computer as a trigger

Stomps

[Stomps]

on a side note, have you got a spare 1ggte flywheel Nathan?

Stomps

[Cuzzo]

Maybe this was telling you its bad mmkay.

The original way you had it wired up made the fuel pump run under all conditions as long as ignition is on? Even when the cars on its roof and the fuel line is cut and its a blazing alight?

Or am i missing something?

[whatthe?]

Who wired this up? Looks well dodgy. COR would have been easier if anything

[Stomps]

Maybe this was telling you its bad mmkay.

The original way you had it wired up made the fuel pump run under all conditions as long as ignition is on? Even when the cars on its roof and the fuel line is cut and its a blazing alight?

Or am i missing something?

No No thats about it..

Look, i know its dodgy, hence trying to fix it.. the reality was that i needed a car or else i would miss a lot of uni and work, as i also tutor a class at uni, i would have probably lost my contract if i missed a class..

I needed a car, now i got one running, now that i have a little more time i can try to fix it..

Stomps

[sideshow]

what ign fue it is

there is an efi fuse?

run pump straight of battery thru a switch temporarily and see if it still blows fuses

if it does then yr engine wiring is fukt
hehehehe

you also might have bad power to the injectors/coil system and overlaoding the wires

another thing is is there any tight wiring

maybe ubder load the engine torques one way pulling on tight wiring and shorting it out

seen it done many times by backyarders

tell me exactyly what fuse is blowing and il tell u what it runs if it was wired corectly

u should never have to run 2 or more relays for a single fuel pump

[BlackSupra]

What could be causing this?

Dodgy wiring!

What gauge wire has your 'mystery' autoelectrician wired into at the ignition barrel?