Misc. 7.3 questions

Discussion in '6.9L IH & 7.3L IDI Diesels' started by BlazeKeeper, Apr 15, 2018.

  1. BlazeKeeper

    BlazeKeeper Registered User

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    Hey all,

    If any of you saw my "IP troubles" thread, you know I had some IP issues. Got it rebuilt, and she started right up. Seems to drive good, too! I do have some other questions, though. First, what is the sensor on the right that I've circled in this picture? Second, what is connector "C109"? It's currently unplugged, and I haven't seen an empty connector to plug it into. Maybe I just haven't looked hard enough, but regardless I want to know what it does.

    Thanks all! Screenshot_20180415-180049_Chrome.jpg
     
  2. Thewespaul

    Thewespaul Supporting Member Supporting Member

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    Of the top of my head I think c109 was the connector that always melts for glowplugs. The sensor is a coolant switch for the high idle and cold advance
     
  3. franklin2

    franklin2 Full Access Member

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    Look for two fat yellow wires in the plug you are asking about. If you do find two large yellow wires, that is the plug that likes to melt. It pretty much feeds everything electrical on top of the engine when you include the little wires also.
     
  4. Macrobb

    Macrobb Full Access Member

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    C109 would be the main connector powering everything, plus gauge wires.
     
  5. BlazeKeeper

    BlazeKeeper Registered User

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    20180416_153631.jpg 20180416_153437.jpg 20180416_153457.jpg Here's a picture of that connector. It seems like 1 wire might have been yellow at one time, but the other looks completely black. I can't find an empty plug where it would plug into. Any idea where it comes from?

    Also, that sensor seems to be broken. I assume it's important and needs replaced? Stupid question, I'm sure, but it runs while unplugged. Also, I know what high idle is, but I'm not sure exactly what could advance is if someone would explain that to me.

    Also, as I was taking these pictures I noticed that 1 of my glow plug wires has broken off. Will it start and be okay with 7 good glow plugs? Or should I just go ahead and replace it?
     
  6. Thewespaul

    Thewespaul Supporting Member Supporting Member

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    That plugs into the ac compressor. The sensor should be replaced, the cold advance just adds two degrees of timing to help warm the engine in cold climate, and to aid with initial startup. The engine will start on 7 but you should replace that when possible.
     
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  7. BlazeKeeper

    BlazeKeeper Registered User

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    This what I need?

    https://m.ebay.com/itm/OEM-NEW-Engi...4115&_trksid=p2047675.c100623.m-1&_mwBanner=1

    I went out and started it this evening. It was in the high 30s to mid 40s today, so fairly cold, but not freezing. It took a couple tries to start it, but once it started it was running incredibly rough and loud. It smoothed out 100% of I gave it some gas. I seem to recall reading something about this being the reason for the high idle when it's cold, because they run pretty rough until warm. Sound like a plausible diagnosis? And theoretically I won't have this issue anymore once the sensor is replaced, right?
     
  8. Thewespaul

    Thewespaul Supporting Member Supporting Member

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    That’s the sensor you need. And it ran rough because it wasn’t running on all 8 cylinders since you’re only glowing 7
     
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