Car wont turn off....

[jammy86]

Hey all,

I've got a little problem. I just got my MS working tonight and when I take the key out the ignition the car wont turn off. when i press the throttle the car still runs even though the dash lights are off.

My setup is that I've got a relay that powers the fuses which is switched by the car ignition. When the key is turned on the relay is closed and power is supplied to all the systems.

I can get the car to turn off if I turn the KEY to OFF and pull the fuse which powers the MS. I've checked that the relay closes when the key is set to off, and it does.

Now if i put the KEY ON and pull the fuse, it keeps running.

I cant work out why this would happen, as they way I've got it rigged up, when I pull the fuse it should switch off no matter if the key is on or off...

Anyone help?

JAmes.

[jsmcortina]

Some installs need a diode in the alternator "charge" light to prevent this exact problem. First off try unplugging that light and see if the problem persists.

James

[jammy86]

Well i went back out the next day and it seems to have fixed itself.... odd.

Cheers though, if it happens again i'll give it a bash.

JAmes.

[hybrid]

Is your alternator light still working though?
Perhaps its blown your alternator light and that is why its not happening any more.

Problems like that don't just normally magically disappear.

[jammy86]

Not sure, I'll have to check that. I've had to put the old ECU back on for now as I was moving across the country. When I get time I'll get back to the MS and I'll check this out. Cheers for the help.

JAmes.

[megaS1]

i`ve had the exact same problem with my series one rst. will check the wire to the light also. main problem i have now it the injector fuse keeps blowing, bless.

[jsmcortina]

What size are your injector fuses?

James

[megaS1]

hi m8y using 5amp fuse from switched 12v supply same as ecu and edis (running ignition operated relay from bus bar in fuse box) . using cossie 4x4 injectors low ohms. my ecu was set up for this when built.

just found ths:

It takes a lot of power to open an injector fast, but very little to hold it open. Note that injectors have gone from 14-plus ohms resistance with 1 amp total current draw to 4 ohms and less. A 2-ohm injector will draw 7 amps at 14 volts if unregulated. That's a lot of amperage for such small wires. Another benefit of a peak-and-hold circuit is that it is self-protected in the event of a short.

and this:

Voltage / Resistance in Ohms = Current in Amps. Example: 13.8VDc / 16 Ohm = .8625 Amps; 13.8VDc / 2.5 Ohms = 5.52 Amps. As you can see the electrical amperage load increase rapidly with low impedance injectors.

on some websites.

so i need a higher rating fuse when using lowz injectors??

what would you reccomend?

thanks.

[megaS1]

i`ve had the exact same problem with my series one rst. will check the wire to the light also.

solved it. i ran the trigger wire for the relay from the back of the barrel instead of the orgininal ignition relay and it`s fine now. so will tap in to the soldered joint up near the relay

[jammy86]

I hate to drag a very old post up but years on I finally am getting the MS in to the car and I had the same problem...

This time I'm older and wiser... the cause is that the Idle Valve and the MS were not powered from the same source on the car. The MS is wired to an output direct from the ignition switch, the valve from the ignition relay, which is triggered by the ignition switch... When you try to turn off the car the idle valve back feeds the ignition switch through the MS, via a flyback diode fitted if you are using a TIP120 circuit for the idle valve, after it is turned off thus holding in the ignition relay. Doh!

The best solution I guess is to run them both from the ignition relay. My solution was to install an inline diode to the MS supply as I had closed the harness back up...