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1989 agricultural 6bt clatter at idle

Discussion in '1st Generation Cummins' started by bob_442, Aug 22, 2019.

  1. bob_442

    bob_442 mad scientist

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    I've got a ~1989 agricultural 6bt transplanted into an '89 Chevy R30 3+3 dually, with a 4l80e behind it. Since it is an ag engine, it is governed at 2100 RPM. Awesome truck. I've had it for close to a decade now. Lately it has developed what I would describe as a pretty loud clatter at idle. It loses the clatter as the RPMs come up. I've been assuming I've got leaking injectors. Sound right?

    I'm looking for advice on finding replacement injectors. I figure if I find something for a 1989 6bt, I'll end up with something from the Dodge application, and it's likely not to be quite right. I'm afraid I'll get an injector more applicable for an engine that can turn a few more hundred RPMs. What should I be looking for?

    Bob
     
  2. u2slow

    u2slow Plan B

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    You can make a educated guess on what injectors will work based on the injection pump type and injector bore size in the head. You still won't know what spray angle is required. (depends on piston bowl size/shape).

    Best to get the the CPL # off the engine and take it to your cummins dealer for correct injectors.

    Injectors won't affect the rpm. I governor spring is usually the answer... rated for 2600, 3200, 3800rpm etc.
     
    RetiringColt likes this.
  3. RetiringColt

    RetiringColt Supporting Member Supporting Member

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    If you're worried about a noise injector you could try the old screwdriver to the ear trick to try to pinpoint the noisy one. Best to replace in sets though. You could have a rocker out of clearance/spec too? These are best to adjust stone cold. I have a Chrysler shop manual if you want the feeler gauge specs?
     
  4. bob_442

    bob_442 mad scientist

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    Yes, please. Adjusting the valves would certainly be easier and cheaper than acquiring and replacing injectors.
     

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