LML Glow Plug Checks

LBZ

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Can you test or enable glow plugs with efilive on an lml or is this tech2 and maybe solus stuff only?

Buddies ‘13 LML is hazing at start up and not going into warm up mode. PPEI is telling him to test his injectors with a scan tool. I always thought if one had a gpcm or gp issue you got a code on post lb7 trucks. Or at least LBZ and later ones.
 

JoshH

Daggum farm truck
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Feb 14, 2007
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LML will throw codes for glow plugs unless the code is disabled.
 

LBZ

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Ya I know. That’s why I don’t understand what they are getting at unless they did disable the codes.
 

LBZ

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Just curious anyone know how long the glow plugs stay on for in a cold start condition?

Is it basically when the light goes out they are off or do they stay on even with the light out till up to temp like the grid heater?
 

darkness

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Jul 15, 2009
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I believe they stay on after starting for a while. There should be a table that has the seconds that they stay on after starting.
 

LBZ

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I know there is a table for the cold start idle time but have never found nothing for glow plugs other than for the codes and monitoring system.
 

Ne-max

I like turtles
Nov 15, 2011
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Yes. Use it all the time. Can turn them off and on. Also can go to data display and read voltage and resistance.
 

LBZ

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Cool.
I found nothing in efilive to be able to adjust their on time or anything. But if a guy can monitor their on/off time via snap on that would be useful I suppose.
 

Ne-max

I like turtles
Nov 15, 2011
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On my lml you can tell when the glow plugs and grid heater are on cause my voltage gauge on cluster stays at 11v for a while. Dont see many lml injectors cause haze at start up
 

LBZ

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Mine too. Buddies doesn’t have a grid heater. Full delete of that with his cp3 swap and all the rest of the piping from sdp.
 

Robby Avery

GM TECH @ FENDER GMC
Jul 31, 2008
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Not sure about efi live showing glow plug values but you can check them quickly key off get a multi meter place one lead on the battery ground and the other check each glow plug measure resistance if any are 55 to 65 ohms there's your culprit could be one or multiple bad takes 5 minutes max
 

LBZ

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Not sure about efi live showing glow plug values but you can check them quickly key off get a multi meter place one lead on the battery ground and the other check each glow plug measure resistance if any are 55 to 65 ohms there's your culprit could be one or multiple bad takes 5 minutes max



Ya that is his next move. Probably would be quite a few bad ones to make his start and make it haze the way it does though but I guess we’ll see what he comes up with.

So far he only had time before dark to check for v’s at the controller and that was good. He did say it didn’t throw any codes when he unhooked the power and started it which I thought was odd but maybe if there is no supply power it doesn’t care if the control circuit is still connected.
 

LBZ

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This is what he sent me today

Tested glow plugs. .5ohm each. Each getting volts. Each getting equal amps. Still does. It injector 2/3 sit at 2.ish and then it will clean up and those two drop.

Attached are screenshots of his balance rate at start up and after it warms up. I’m thinking maybe he has a couple injectors on their way out. He just did a cp3 swap and hg’s a couple months ago.

0124175b93a7f6731e3ce09a426e72ab.jpg
7f848de27a3bb312abcf6e76142f5373.jpg
 

Josh154

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Sep 28, 2015
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Who’s tuning? What kind of haze and for how long? Mines cp3’d, fully deleted, no grid heater and full sdp pipe kit. I get the occasional blue/white puff of a deleted truck at startup when sitting for 8 hours + but that’s it
 

LBZ

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PPEI

Gets the same white puff at start up but then a blue and white haze until it gets up to at least 140F coolant temp.

His truck has never had the grid heater hooked up since he bought it.