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More Truck Issues

Post in 'DIY and General non-hearth advice' started by Czech, Aug 8, 2008.

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  1. Czech

    Czech Minister of Fire

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    It's been a couple weeks since I last posted about the '97 GMC Yukon 5.7L, then it was the A/C. That seems better now, but I have other issues I was hoping for some help on. First off, I went to turn the fan switch on, the speed switch would not turn easy as usual. At first a wiggle and I'd get high and off, now nothing. Any advice on replacing this? Second, just the last few weeks, the truck has started idling rough on start up, then stumbles a bit getting going. Once running she's fine. I planned on doing plugs, fuel filter, pcv anyways, anything else you can think of? I'll get the codes read on my way home tonight at the auto parts store (free!), if you recall the truck aways codes as the cats are not functional. Just want to makes sure there are no other codes hiding. Thanks all, have a good weekend!

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  2. homebrewz

    homebrewz Minister of Fire

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    Get a replacement switch from the parts department at the dealer. You'll most likely have to take the dash partially apart to replace it.

    As for the idling issue, it could be any of the things you mentioned, including any number of other things. The problem with letting the check engine light stay on is that you won't know when it throws a new code. Best to have the codes read and figure out what you need to do from there. If the code doesn't shine any light on the rough idle, go ahead and replace the stuff you mentioned.
  3. Czech

    Czech Minister of Fire

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    Thanks brew. The rig has 230000 miles on it, it codes because the cats are open and the o2 doesn't like. I know there's a way to program the o2's, just haven't gotten around to that. I stop by the parts store every week or two, they read for free and are nice folks to shoot the breeze with. We actaully have a pool for what will finally kill the truck, I need to keep here going!
  4. bruce56bb

    bruce56bb New Member

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    i think home brewz is on the money on the switch.

    the hard start sounds like your fuel pump is getting weak. have someone
    run a line pressure test to be sure.
  5. struggle

    struggle Minister of Fire

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    Sounds like the dash switch is bad but could also be a bad resistor block for blower motor as well. They typically go only high speed when they burn out.


    Rough idle could be intake manifold leaking and then seals up after it warms up. When was it last replaced? My 97 5.7 did that and after it warmed up it ran smooth. Replaced intake gasket and it never did it again.

    Central point injection has its own set of issues with what you are describing as well. It really could be anything.
  6. Czech

    Czech Minister of Fire

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    Agreed with the switch, I'm pretty much convinced the start issue is the fuel regulator valve which bleeds fuel back to the tank while operating and should seal when not. I popped on my pressure gauge to the rail, she's bleeding pressure back to the tank. The great news is that GM made that regulator very easy to get at, LOCATED UNDER THE UPPER MANIFOLD! Done this twice now, and also injectors and a lower manifold gasket, still sucks to do this much work to get at this $40 part. Ah well. Thanks GM, great thinking, next time around I may buy a Toy. Any ideas on getting the darn dash apart to get at the blower switch? I may need that working before winter here in MN if you get what I mean. Thanks all, hope the start of your weekend is better than mine, although I don't mind twisting a wrench also. Could be fishing.....
  7. Czech

    Czech Minister of Fire

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    No codes BTW, had those read tonight. Just the 'hey you messed with cat' codes, my o2's aren't happy. Not related I don't think, this is a fuel issue, not a fuel combustion issue imho. Strug, I trouble shot the blower motor, unplugged and gave it 12v on the side, runs fine. Has to be the switch, now just to get at the darn thing. Just did the manifold last year, started lower and worked my way up so I'm hoping that's cool (no pun intended!). Thanks all. Just when I wanted to hook up the H2 baking soda generator too, darn it!
  8. Hogwildz

    Hogwildz Minister of Fire

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    These are warning signs to get rid of it, time for a newer model.
    Its all nickel & dime & more from here on out.
  9. Czech

    Czech Minister of Fire

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    I know Hog, I know. She's kind of like an old girlfriend right now, I know I shouldn't be spending this much time and money on her, but I kind of love her still. I don't mind a little wrenching, and the payment is right on my budget when it's a $40 part. She gets my boat to the landing also, that is of utmost importance!
  10. bruce56bb

    bruce56bb New Member

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    [quote author="GotzTheHotz" date="1218267719"] Any ideas on getting the darn dash apart to get at the blower switch? quote]


    the main dash faceplate is held on with clips. tilt the steering wheel down and start pulling;)
  11. struggle

    struggle Minister of Fire

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  12. Redox

    Redox Minister of Fire

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    Not sure if it applies to your model year, but some of those generation had issues with the intake gasket leaking. Is it using coolant up?

    Chris
  13. Czech

    Czech Minister of Fire

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    Ok, after a few 12 packs and some smokes, I got her. The dash really wasn't that bad, as Bruce and others said, just clips, steering wheel down, shift handle also, popped right out. Replaced the fan blower switch, no biggy, works fine now. The regulator was an issue, got it done but then realized I must have leaked coolant into the upper manifold in doing so, she would not start. Hard to compress water. Anyways, pulled the plugs and cranked her, replaced the plugs, other than a vacuum leak she's running well enough to get the boat to the river twice this weekend. That's good. Thanks all!
  14. Highbeam

    Highbeam Minister of Fire

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    I have a 98. I've replaced the mirror without pulling the entire door panel off. Just the upper triangle piece and my fat fingers got in there fine. In my case some hoodlum knocked the entire mirror onto my hood while I was parked on the street. Cheap replacement though. My fuel pump took a dive last winter, these fuel pumps either work or they don't and replacing them at the dealer is more than 1000$.

    I am putting my 98 on the market while it still is fairly dependable and before the nickel and dimes start coming in. These are fine trucks but they only last so long. It will be sad for me since it has been great and is a looker.

    The good news is that the market for lightly used 3/4 or 1 ton full sized trucks is in the pooper. I plan to pick up a dodge diesel that was bought 2-4 years ago for 50% of new or 20-25000$.
  15. struggle

    struggle Minister of Fire

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    My mirror was a power one and the harness was buried just out of reach so I was not able to unclip the harness so I took the panel off. Otherwise it could have been done like yours with just pulling it back a bit.
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