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EGR/Tranny??? HELP!!

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by shane74, Aug 12, 2003.

  1. shane74

    shane74 1/2 ton status

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    Ok, I did a search, but really didn't find what I was looking for. This may be a bit long so I apologize before hand!

    I borrowed my bro-in-laws '87 sub (TBI 350 V8/ and 700R4 trans) to tow a 28' camp trailer back to my place. Along the way, it started to run very rough and lost power in a big way and started shifting poorly. I got the sub home, and did a basic tune up (plugs, wires, rotor, cap, fuel filter, and timing). It still ran VERY rough. I pulled the ECM codes, there were none. I gave up and took it to a shop. I was told the EGR valve and the tranny were toast. I was quoted $2500 to repair everything. My jaw hit the floor and I took the sub home. I'll do the EGR myself. My question is this...can a bad EGR valve affect the way the transmission shifts? It shifts VERY hard from 1st to 2nd, revs like a muther between 2nd and 3rd and really doesn't every shift in OD. I noticed the vacuum tube for the tranny runs off the same line as the EGR. Any ideas about this?
     
  2. RATAH

    RATAH 1/2 ton status

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    a 700r4 has no vacum
    it works of the detent cable and the computer
     
  3. shane74

    shane74 1/2 ton status

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    I got the same answer from my tranny guy, but he also added that if the EGR is bad, it will cause the engine to lose power and also lose torque. It'll be like running on 6 cylinders instead of 8. That will in turn mess up the computer and the shifting will be slow to react and hard as hell when it does, or it may not shift at all. He put his money on the EGR valve being the cause of the problems. He's been doing tranny's and building race cars more than 30 years. He hasn't turned me wrong yet, so I have some hope here.
     
  4. dyeager535

    dyeager535 1 ton status Premium Member

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    You can probably test that theory by simply disconnecting the EGR vacuum line and plugging it, and going for a test drive.

    EGR isn't a constant thing, so the truck will need to be fully warmed up before you may notice if it worked or not.
     
  5. funkycold

    funkycold 1/2 ton status

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    I have a '89 sub and had a similar problem with a lose of power and running poorly, but did not have the tranny shifting problem. it would run really bad and use excessive fuel. it ran like it had an air leak and would back fire badly. i replaced the EGR and it ran a lot better. you can check the EGR by trying to press the plunger from the bottom of the valve, if it moves then it is OK, but if it is stuck it needs to be replaced.
    good luck!
     
  6. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

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    [ QUOTE ]
    I got the same answer from my tranny guy, but he also added that if the EGR is bad, it will cause the engine to lose power and also lose torque. It'll be like running on 6 cylinders instead of 8. That will in turn mess up the computer and the shifting will be slow to react and hard as hell when it does, or it may not shift at all. He put his money on the EGR valve being the cause of the problems. He's been doing tranny's and building race cars more than 30 years. He hasn't turned me wrong yet, so I have some hope here.

    [/ QUOTE ]
    Give it a shot. One thing that does sometimes happen is the ports in the intake get plugged up and cause some EGR issues. It may take pulling the throttle body and running a coat hanger up through te passage. then vacuuming the crud out of the intake. The port for the EGR is right between the two barrels on most intakes both carb and TBI.
     
  7. shane74

    shane74 1/2 ton status

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    Thanks Grim. I'll keep that in mind when I pull the valve. I'll check the port to see if it's plugged up or has any crud in it.

    Thanks for the replies everyone. I'll post after I change the EGR and see what happens.
     
  8. shane74

    shane74 1/2 ton status

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    Well...CRUD! The EGR fixed the engine probelm, but when I pulled the pan on the tranny, the fluid looked like silver metallic paint! /forums/images/graemlins/eek.gif /forums/images/graemlins/angryfire.gif /forums/images/graemlins/angryfire.gif /forums/images/graemlins/angryfire.gifIt's shot, that's for sure. dammit.....
     
  9. Muddytazz

    Muddytazz 1 ton status

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    ewwwwwwwww...thats not good
     
  10. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

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    [ QUOTE ]
    Well...CRUD! The EGR fixed the engine probelm, but when I pulled the pan on the tranny, the fluid looked like silver metallic paint! /forums/images/graemlins/eek.gif /forums/images/graemlins/angryfire.gif /forums/images/graemlins/angryfire.gif /forums/images/graemlins/angryfire.gifIt's shot, that's for sure. dammit.....

    [/ QUOTE ]

    $150 for parts to rebuild it including a reman converter. It's not that hard. Might need to helicoil a few things.
     

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