glow plugs light

[1logger]

Hi all
one of my mates bought a 93 mu today when starting the glow plug light flashes an there seems to be voltage drop as it happens any ideas as to fault.

thanks
jeff

[geeves]

flashes?? It should come on then go off before starting but only once. The 2.8 will come on for under a second unless the temp is less than 3C when it changes to 10 sec. It doesnt matter as the 2.8 will always start even with no glow plug. The 3.1 works out better how long to glow for and you do need to wait for the glow plug light to go out before stating. Glow plugs can draw 90 amps hence the voltage drop.

[James W]

You are possibly going to have to chase this fault. Check the voltage on the bus bar to all the glow plugs when glowing. If nothing, then it's a glowplug controler. If power to glowplugs then check each glowplug in turn. If they are ok, it might be a sensor somewhere consfusing the glow plug controller. One of which is on the water thermostat housing.

[1logger]

I should have said glow plug heat was not used but after starting it flashes for around a 2 mins with the valtage drop each time it flashes on .
I have not seen this before not on mine anyway .

thanks jeff

[kykin]

i know this ones old but i just bought a 91 2. Mu on thursday and the glow plug light on the dash is coming on at random times and when it comes on the heat gauge goes up about 1 quarter. then when it goes off randomly it drops the heat to normal again? and then on saturday morning the battery was down to 10volts and im jumpstarting it now

any ideas?

thanks

[geeves]

Youve got a wireing fault somewhere that could be a little hard to find. The good news is that In aus you are unikly to need the glowplugs so try removeing the glowplug fuse first If the symptoms disapear consider it fixed.
On a 2.8 diesel you have direct injection which always starts very easy. The glowplugs are not meant to glow for more than half a second above 5C The engine will happily start without them below freezing

[kykin]

sounds good, where's my fuse? hehe.

and whats the button for to the right of the steering wheel right of ignition, it looks like an engine symbol with a coil in it. iv tried it on and off and it dosent seem to change or affect anything. not even lighting up......

iv been reading around and seems you know alot man, thanks for sharing ur wisdom. very helpfull.

[geeves]

Its a fast warm up device. At water temps below 5C and switched on it closes a restriction in the exhaust keeping more heat in the engine. You dont need it anywhere in Aus. Theres only a couple of places in NZ where using it would make a difference

[kykin]

kykin said:

sounds good, where's my fuse? hehe.
.

[tealz]

Does the 3.1 use the same glow plug system?

[geeves]

the 3.1 has a more compicated system that changes the glow time over the whole temp range. A 3.1 has indirect injection and is much harder to start without glowing first.

[tealz]

If I glow my 3.1 only once it smokes but if I glow it twice it starts up fine with no smoke. It fires with out the excess fuel smoke. It is like the glow timer is too short. Glowing twice is the best option for indirect injection

[ken]

I don't think the glow plugs actually switch off when the indicator light goes out. If you wait for a short time after the light goes out you can hear a relay click and that is when they switch off. I had a car on which the timer seemed too short and it always worked by delaying starting until the relay clicked. Or am I under a delusion?
Ken

[3vilc]

That is the case with the 3.1 at least, glow plugs dont switch off for a while after the light goes out. I used to find similar on my old bighorn, if u wind the starter when the light goes out it would struggle to fire, if you waited til the relay clicked off it would start fine

[kykin]

got mine sorted today. the battery would not get charge from the alternator but we could see there was 14+ volts flying round the bay. the wire from chassis to side of block just below battery was bolted in but was bottoming out, so a washer and a quick tighten made the glow plug light go away during running. but now the battery is getting 15.8 ish volts when running, i rekon ill be topping up my battery no end till i sort out where my regulator is and try something new............. any one had this before

[MattMU]

Kykin it sounds like you have fried the voltage regulator and I wouldnt be running like that if you want the battery to last for any significant time. Is the chage voltage stable at 15 volts or does it raise with revs, not that regulators are adjustable anymore...just more damage will occur quicker if the charge voltage isnt stable.

That voltage will quickly over-charge the battery and destroy it. I dont believe the reg is separate from the alternator despite running an external charge relay. This is just to control the charge light.

All the best with it mate.

Matt.

[gecko]

kykin said:

got mine sorted today. the battery would not get charge from the alternator but we could see there was 14+ volts flying round the bay. the wire from chassis to side of block just below battery was bolted in but was bottoming out, so a washer and a quick tighten made the glow plug light go away during running. but now the battery is getting 15.8 ish volts when running, i rekon ill be topping up my battery no end till i sort out where my regulator is and try something new............. any one had this before

i noticed this happend to mine shortly after buying it, i took it to our local autosparky and he said the alternators on the way out and its not a good idea to be running it like that, luckly my MU came with a spare alternator, what a pig to replace though! lol especially on a wet day, (take battery out, unbolt AC, dont disconnect AC lines/hoses just move it to where the battery was....) im sure some designer somewhere picked up the alternator and said "hey we can build a car around this" lol

anyway the autosparky said if the alternators done that, best to replace the charge relay, cause it could have been damaged and if it has it could just wreck the replacement alternator.

[kykin]

yeh it dosent look like a nice spot to get to. its not curretly being driven, maybe once every 2 weeks, so im investigating a way to better protect/relocate the new alternator since i dont wanna do it again after a few mud crossings.....

any ideas?

[geeves]

I agree with auto sparky on the charge relay. Safer to replace as a pair. New relay is only 40 or so.
Alternator isnt that hard to get out Only a little bit harder than the oil filter and look how often they are changed.
After haveing a new clutch put in my other car (toyota carib 4wd) I apeciate how easy the isuzu is to work on. 10 hours labour by a toyota trained mechanic Luckily this included a club discount