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7.3 idi with turbo runs rough above 1000rpms

Discussion in '6.9L IH & 7.3L IDI Diesels' started by 1978FrankenFord, May 11, 2019.

  1. 1978FrankenFord

    1978FrankenFord Registered User

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    1994 7.3 idi with a turbo will idle all day long and starts up like its a brand new truck. When it gets past 1000 rpms it starts stumbling and will blow like a faint blueish type smoke. Its not a really thick white smoke like injectors. This truck has brand new glow plugs, injector pump and the new not reman injectors have maybe 20 minutes of run time on them. Im kind of at a loss. I can rev it up past 1000 rpms itll stumble and then when i go back to idle it idles normal. I have videos too if you want i can post them and send a link. This truck does have quite a bit of blow by also. Any help would be appreciated, just trying to get her back on the road, thanks!
     
  2. Thewespaul

    Thewespaul Supporting Vendor Supporting Member

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    How did you set the timing when you installed the pump?
     
  3. SLC97SR5

    SLC97SR5 Full Access Member

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    Have you run it out on the highway at high RPM's for over 20 minutes?
     
  4. Scooch

    Scooch Registered User

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    Definitely agree how was timing done but also where did the injection pump and injectors come from?
     
  5. 1978FrankenFord

    1978FrankenFord Registered User

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    Timing has been set by lining up the 2 marks then by the timing light. It has ran fine for 18k miles. Just started doing this on me. I got injectors from advance auto because I thought that was the issue. They are brand new bwd
     
  6. 1978FrankenFord

    1978FrankenFord Registered User

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    And yes i ran it for quite awhile on the highway at 70 mph for more than 2 hours. I was out of town when it happened and drove it home
     
  7. Thewespaul

    Thewespaul Supporting Vendor Supporting Member

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    Youve got two problems here, one being your timing is not correct, and two being the parts store pump.

    To fix the first issue, you need to find someone near you that has the proper equipment to time the engine correctly, if you look at the tech articles at the top of the page you will see a thread that is a list of everyone who has timing equipment, you should be able to find someone in your state.

    To explain my second point Ill tell you about one of my customer's experience with a parts store pump. He has a built engine from me, with an upgraded turbo and 130cc IP. He uses his truck for hot shot work and originally had a 90 cc pump on his stock engine till he blew a headgasket. He sold the 90 knowing he would want more fuel for the better engine, so he sent me a core to build but in the meantime he figured he would run a parts store pump while he waited for my pump to be done. He bought a pump and took the fuel screw cover off to turn the fuel up while he had it out and found the screw was already bottomed out. The pump had not been rebuilt, just screwed with on a stand to get it close enough to spec. Theres a reason why those and ebay pumps are so much cheaper than the quality rebuilders.
     
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  8. IDIBRONCO

    IDIBRONCO IDIBRONCO

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    Although I didn't see where you said the pump came from, I saw that you bought the injectors from Advanced Auto. Their "new" ones won't be any better than an injector pump from them.
     
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  9. 1978FrankenFord

    1978FrankenFord Registered User

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    Thats nice. I figured the pump and injectors would be alright. I got a stanadyne pump which ive heard things about them but figured itd be an alright pump. Ill have to check on the timing and make sure its spot on. That sucks on the pump i paid like 700 for it or something like that. And injectors i paid around 600 for
     
  10. IDIBRONCO

    IDIBRONCO IDIBRONCO

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    Stanadyne is the only one who made these pumps originally, so there's no issues there. It's just with the parts store (lack of) quality. Since the last one of these truck rolled off of the assembly line in 1994, chances are that it's probably not a new pump. Stanadyne may have continued making new pumps and injectors for a while after production this engine stopped, but not 25 years later. Incomplete vehicles may have taken longer to be fully ready to sell than regular trucks and vans and titled as a later model year, but they left the Ford plant before production stopped. For example, I have seen a bus that was titled as a 1995. It had a 7.3 IDI engine and it also had a C6 transmission. How long do you think that one sat around before it was completed?
     
  11. 1978FrankenFord

    1978FrankenFord Registered User

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    I gotcha. Yeah that bus is pretty weird having a c6 and an idi in 1995. I tried advancing the timing and it didn’t really do much to improve it, maybe a small amount. Retarding the timing made it seem worse. I only advanced it about a 1/16 of an inch. It does it more while its cold and then when it worms up it gets a little better.
     

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