IDI HELP NEEDED!!!

Discussion in '911 Diesel Down!' started by Austinfee, Jan 12, 2017.

  1. Austinfee

    Austinfee Registered User

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    Hello everyone

    For starters I have a 1990 f250 7.3 idi with a turbo , 4x4 , e4od trans

    I was just test driving my truck after a ongoing project doing break shoes , cylinders , bearings and seals. When the light turned green, it was very hard to get my truck to go. It almost felt as if I was towing a huge trailer. No torque at all & high rpm's to get it to move. When I looked down at my rpm's , I realized the gage stoped working. All it read was 0. I also noticed my over drive light was dimmly lit. My first thought was something went wrong when I did the wheel bearings, but the truck glides smoothly with no feeling of anything holding it up.
    Also when I get to higher speeds there no hesitation of moving faster. It's been sitting for 2 weeks in cold weather, but I've been driving it for about 20 minutes prior to this problem with everything going fine and the trans shifting normally. Also a side note, the trans still shifts fine! The only test I did was to remove the over drive switch connection ( nothing changed )

    Please feel free to comment anything you think might work cause right now I'm clueless as to what it could be.

    Thanks for reading.
     
  2. SebastIDIan

    SebastIDIan Full Access Member

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    Will the truck move as it normally would if you use the lever to manually shift through gears?

    I assume your dead tach and tranny problems are related, check the connections to your tach sensor next to the oil filler tube. Replacing the sensor would be next on the list.
     
  3. Austinfee

    Austinfee Registered User

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    Just tried to manually shift and it still does the same thing. Part of me think that it might be 2 different problems that hit at the same time. #1 like you said, something just went wrong with the tack like the sensor. #2 I think I might possibly have a bad neutral safety switch. From what I can hear from the transmission sounds like im starting out in 3rd gear.
     
  4. icanfixall

    icanfixall Official GMM hand model

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    You need a tach signal for the trans to operate correctly. You could have a bad tach sender or it could be dirty. you could have a bad teca relay and it wont send power to the tach circuit. the relay is found near the windshield washer. It might be brown or black. then finally you may have a blown fusible link. Utube has a great vid on how the teca gets power and you can easily make a jumper wire to test if the power is reaching it.
     
  5. chicken bones

    chicken bones Docker

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    I just had my POSM ( Programable odometer speedometer module ) go out on me, the tach and POSM are nessary for the Transmission to work properly.Cluster Fix
    4345 Twin Lake Ct
    West Richland, WA 99353 $ 179.00 to have your Cluster Repaired.
     
  6. bugman40284

    bugman40284 Registered User

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    I know this is a shot in the dark, but check your grounds. I had a bad ground on my 85 and it caused all kinds of crazy problems, low power, gauges suddenly losing power, random surging. My truck was a manual so I am not familiar with your setup, but grounds are a fast check.
     
  7. Sidewinded_idi

    Sidewinded_idi Full Access Member

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    Sounds like you started in a high gear. Definately tach related. Figure out why it’s not working. That’ll throw the od light. And for anyone else reading this our psom is the same as the gassers which are abundant at the junkyards. Pull a cluster, pop the clear cover and pull the speedo out and put in your cluster. It’s super easy and my junkyard charges 8$
     
  8. BigRedTank

    BigRedTank Registered User

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    I had a similar problem with a 94 E4OD. Would take off as if in 3rd gear. My computer needed to be replaced for $100.
     

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