Starting problem.

[markistall]

Hey guys, over the last few weeks I've been having a few issues starting the engine on my 04 4.2 gu ute. I thought it was the glow plugs. So I replaced them, (they were due anyway) that didn't help. I put a multi meter on the connection to the glow plugs and it showed constant current weather the ignition was on or off, not sure if that's normal or not, or if maybe I have blown a relay or something else. Any ideas will be appreciated. Only way I've been able to start it is with "aerostart". And then once it's warm it can start on its own.

Thanks for your time guys.

[threedogs]

Got nothing. check all vacuum hoses, change fuel filter.
just trying to get the marbles rolling

[WYLD333]

So your saying your glow pulgs are powered up even when the engine is off?

[lorrieandjas]

Mate - that sounds odd. I know there are a couple of ways glow plugs operate but in neither case should they be powered with the ignition off. How did you measure your current?

Jas

[markistall]

sorry it has taken so long to respond guys. been off the radar for a bit. but yes, there is current flowing to the gglow plugs at all times, i have replaced one of the relays, but looking at the schematic of the system i think there is 2 relays and an ecu that could all be at fault. i measured the current by sticking the positive thing of my multi meter into to plug that plugs into the glow plugs and puting the negative ne on the negative battery terminal, as you can probably tell from how i said that, i am pretty clueless when it comes to electronics. but i had my second year electrical engineer mate look at it and he was stuck for ideas too. i've gotten around the problem for the moment by putting a manual switch in the cab directly to a relay. and i just hold it for a few seconds and it starts okay. but i would like to make it back to manufacturers specs haha

[WYLD333]

Hey mate you would of been measuring voltage not current, current/amps is measured with a clamp meter. just out of intrest how many amps was it pulling?

[Yendor]

I don't think the utes have the glow plug system that runs the two relays. If it does the second relay will be mounted beside the first relay on the driver side inner guard.

Was the glow plug waring light in the dash working correctly?

With a voltmeter or test light, connect the negative to the negative of the battery and the positive to the busbar at the glow plugs then turn the ignition on, what is the reading? (engine must be cold). You should not have power at the busbar when the ignition is off.

Normally the glow plug ECU doesn't fail unless you have had water into the cab.

You could possible have a fault in the engine coolant temperature circuit.

First step is to confirm you are only getting power to the glow plugs when the ignition is turned on and how long it stays on for before it switches it's self off.