<DIV>Hi!</DIV>
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<DIV>I traded some work on a Nissan for an Isuzu Diesel but it won't Start. I have to use starting fluid ( I know, a big no, no) to start it.</DIV>
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<DIV>So I checked for power to the glow plugs and there was 4 1/2 volts. One glow plug had 0 continuity and the others? Who knows if they are bad - the continuity reading kept going up and up and up!. So I bought 4 new glow plus, expecting to fire it up.</DIV>
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<DIV>No go.</DIV>
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<DIV>Still won't start.</DIV>
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<DIV>What else could be causing this problem? </DIV>
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<DIV>It's a 1981 Isuzu I-Mark diesel with 120,000 miles. Runs good when it starts! </DIV>
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<DIV>THANKS in advance!</DIV>
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<DIV>Ben
</DIV>Edited by: aware

Hi everyone,


Here is what I found:


Rechecked voltage at glow plugs using a digital voltmeter andit showed no voltage - however, it blipped for a second as it if WAS going to show voltage. (Here is where an analog voltmeter would be handy)


Checked backwards to the wires to the relay, same thing.


There was voltage to the relay.


Then I noticed (with someone else turning the key) that the relaly only went on for half a second, so no wonder the glow plugs didn't warm up.


I unplugged the sensor with no change.


So I put 12 V at the relay to energize it and still didn't have voltage at the plusBUT I did at the relay. Come to find out the plug-in connection near the bar going to the glow plugs was corroded. Cleaned it and now I have 12 V at the glow plugs.


In reading, I also found out why the relay was shutting down. The system monitors the amperage/voltage to the plugs and if it's not right, it cuts off. SO with only 4 1/2 V initially and zero later, it cut off the relay. As soon as there was sufficient voltage at the bar, the relay stayed on.


If a glow plug burns out, it's possible the system wouldn't work!


I believe the 2 small wires that go to the bar monitors the voltage or amperage. Sort of looks like a bus bar used for amp readings.


Another thing, is that there is 12 V to the glow plugs only for the period of time the light is on, then it goes to 7 volts through the second relay.


I read that the on time is 180 seconds. Not sure if that is true but my glow plugs stay energized after the engine starts. Haven'tmeasured it yet because I'm afraid they'll burn out!


Does anyone know if that is correct?


Several websites verify this: http://rubyenterprises.indianyellowp...glow-plugs.htmfor one, Apparently this is 3-phase heating.


See page 38 here: http://www.adpdist.com/beru_glowplug...ion_na2004.pdf #search=%22isuzu%20glow%20plugs%20%22180%20seconds %22%22


Maybe it depends on the type of glow plug.


ANYONE?


THANKS!

Ben