GM-GMC: 85 Chevy Suburban 6.2l, chevy suburban, glow plug

Question
Good morning Harry,
I have an '85 suburban k10 w/ a 6.2l diesel motor in it. I am having a problem with the glow plug heating system, I believe. Up until last week, when I would plug my 6.2l in, it would fire up as soon as the glow plug lamp would go out in the cab.  Now, it takes several tries or even a quick shot of starting fluid to get this beast to crank over... Any suggestions?  BTW, I do have voltage on the cord as far back as I can reach under the truck.  Is it possible that the cord could have come loose?  Any sugguestions would be greatly appreciated.  "Stuck in the COLD-Bob K"

Answer
Bob,

I think that you are a little mixed up about the cold starting devices on your diesel.

The cord that you plug into a wall outlet is for the block heater.  Though it glows, like an electric stove element, is is NOT a glow plug.  The element is located in the middle casting plug hole on the driver's side of the block.  If it fails, it must be removed and replaced after draining the cooling system.

There are eight glow plugs installed on a GM 6.2/6.5 diesel, one per cylinder.  They are located right under the the injector nozzle and provide a source of heat to cause the fuel to burn when cranking a cold engine.  Glow plugs fail and, if more than one or two go bad, the engine may not start as a result.

By the way, using starting fluid with a glow-plug equipped engine is asking for a fire or explosion.  You can ruin your engine and/or set the vehicle on fire if the starting fluid meets an energized glow plug.  Use WD-40 instead.

Take a test light and check each glow plug by removing its connector and see if the glow plug has continuity.  You can also perform this test with an ohmmeter and good glow plugs have about one ohm of resistance when cold.