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CAT 420D-Perkins Injector Pump Filter?

Discussion in 'Tractor/Loader/Backhoes' started by JCinNC, Sep 11, 2021.

  1. JCinNC

    JCinNC Well-Known Member

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    Wondering if anyone knows if there is a filter in the injection pump inlet.
    CAT 420D
    Perkins Injection Pump

    I have the inlet disconnected and open. Can't seem to hook anything. Or maybe chicken to hook the WRONG thing. :(

    Thanks.

    JC.
     
  2. Nige

    Nige Senior Member

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    According to your Serial Number this is the injection pump/fuel injector setup.
    Really need someone like the @pumpguysc to comment regarding the filter (or lack of one).

    upload_2021-9-11_18-38-53.png
     
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  3. Delmer

    Delmer Senior Member

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    I'm not thepumpguy, don't have access to anything definitive, and have never dealt with that style. But it has the same style distributor end, with the same inlet in the middle, presumably? the same vane pump and regulator inside that inlet. So I'd expect the same sleeve style mesh screen. Have you looked at the cav inlet screens to see what to expect?

    The worst that can happen is you puncture the plastic screen and have to wait to get a new one, or possibly? disrupt the spring and regulator valve and have to take that inlet piece off, not the whole distributor, just the inlet fitting is all.
     
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  4. JCinNC

    JCinNC Well-Known Member

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    Thanks. Here's a picture if it helps.
    CAT420DPerkinsInjectorPump.jpg
     
  5. JCinNC

    JCinNC Well-Known Member

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    Some more information. I'm getting poor performance and/or just overall inaccurate performance.
    Symptoms:
    Slow to start.
    Starts and idles.
    Pushing the accelerator to the floor did nothing to the idle at start. I put the accelerator full on and let it run a bit. After a few minutes it maybe increased 400-500 RPM?
    Not sure the tachometer is accurate. Anyway, it leveled off at around 1400RPM going by the tachometer. Wouldn't go up any further.
    And now, it does not go down any either. Just stays at 1400RPM no matter what you do with the accelerator controls.

    What I've Done:
    Checked fuel. It appears to be ok.
    Checked air filters. Appear to be ok but took them out and blew them off anyway.
    Replaced water separator/fuel filter.
    Removed inlet line to injector pump. Tried to hook a screen that may be in there but didn't have any luck. Looked down in there with a mirror and light. Looked like some sediment in there so I rigged up a small hose to the shop vac and carefully sucked it out. Checked again with mirror. Looked better.
    Put it all back together. Same performance.

    Also, it has this Perkins tag on it, but the pump is cast with Delphi in it.

    Thanks for any ideas.

    J.C.
     
  6. Delmer

    Delmer Senior Member

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    What's the history on this? Sounds like a lot more than just a screen is going to fix.
     
  7. JCinNC

    JCinNC Well-Known Member

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    Oh. No history to keep from anyone. Just another piece of equipment that belonged to my Pops. It has been sitting more than being used. Stabilizers in fuel.

    I would keep it cranked once in awhile. Usually just cranked it and let it idle up to temperature, then shut it down.
    Recently wanted it to put it more through it's paces and it's acting like this.

    Thanks.
     
  8. Delmer

    Delmer Senior Member

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    If it has a screen in the injection pump inlet, it will look just like the one in your ford. Doesn't the end of the injection pump look very similar?

    If it was mine, I'd drain the tank. Find where to buy a high percentage biodiesel, B20 or more, and fill the tank, then let it run for a couple days, checking every few hours to see if it has any throttle response. Sounds like it's so gummed up, that it's either time for a pump rebuild, or desperate measures. If the biodiesel doesn't work it loose, add 20% ATF and let it run another day?
     
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  9. JCinNC

    JCinNC Well-Known Member

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    They do look similar. I cranked today.
    Difficult to start. Long cranking until the engine takes over and runs.
    Beginning idle according to the tach is about 800 RPM.
    Left alone (no touching of the throttle) and RPM increased by 400 to 1200 RPM according to the tach. Also the increase was noticeable audibly.
    Just mentioning in case the tach is inaccurate.

    Thanks for all input.

    J.C.
     
  10. JCinNC

    JCinNC Well-Known Member

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    Update: Got the screen out of the inlet side of the injector pump. Dirty, but not overly so. Cleaned it up, reinstalled, cranked it up, and....
    No change. :mad:
    She idles at 1700 RPM by the tach.
    Push the pedal to the floor or anywhere in between.
    She idles at 1700 RPM.
     
  11. heymccall

    heymccall Senior Member

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    I know this is going to sound condescending but, if the engine speed is too high, have you pulled the hand throttle back to turtle?
     
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  12. Delmer

    Delmer Senior Member

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    Are the foot and hand throttles actually moving the shaft on the pump? Move the linkages by hand and see what moves on the pump.

    When it's idling at 1,700, does it have any governor action? Like if you operate the hydraulics will it slow the engine down, but not really make it any louder, or will it try to give it more fuel to maintain the RPM.

    IF you don't want to go to the trouble of draining the whole tank, you could run it on a five gallon boat tank of 2/3 diesel 1/3 ATF and let that sit while you try to figure it out.
     
  13. thepumpguysc

    thepumpguysc Senior Member

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    Definitely try to run the throttle BY HAND.. if the throttle moves from stop to stop and the rpm’s don’t react, u have internal pump problems..& there’s no magic elixirs that’ll fix it..
    DO NOT try to take the top cover off.!!
    There’s way to many gizmos that have to be linked at the same time for this to b a diy project.. sorry.
     
  14. JCinNC

    JCinNC Well-Known Member

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    Thanks all. Came in to the house HVAC out. Digging into that. Hope it doesn't have an injector pump on it. :p
     
  15. JCinNC

    JCinNC Well-Known Member

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    Thanks all so far for the input and recommendations.

    Current symptom is it just idles, or runs, at around 1200 RPM by the tachometer.
    Pressing the foot throttle does nothing. No increase, no decrease.
    Moving the hand throttle does nothing. No increase, no decrease.
    I have confirmed the linkage functioning moving the throttle linkage on top of the injector pump from stop to stop.
     
  16. JCinNC

    JCinNC Well-Known Member

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    Almost forgot, you asked if using anything on it affected the running. Yes, if you turn on the A/C it decreases current running speed a good amount and does not idle back up. So loses about 400 RPM and stays there.

    Question, is there any filters in the tank?

    Thanks.
     
  17. JCinNC

    JCinNC Well-Known Member

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    Also, if and when it gets to me removing the injector pump, any do's and don'ts to share?
     
  18. thepumpguysc

    thepumpguysc Senior Member

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    Oh, HECK YEAH.!!
    The pump and engine MUST B TIMED BEFORE REMOVAL..
    That engine is timed w pins.. if u look closely at the breakdown someone posted, at 6:00 you can make out a hole for a pin..
    That pump drive is NOT KEYED..
    Your best bet is to pull the timing cover(front cover) which is a TOTAL PITA.!! Fan, belts, alt... etc.. THEN you’ll be able to see what’s what..
    Ur gonna hafta get a manual..
    Oh, and the pump has a locking mechanism on the side of the pump..use it..
    Don’t think for 1second that u can lock it anywhere and the shop will put it back the same way... it doesn’t work like that..
    U might wanna think about finding a fuel shop that’ll take the job in..
    good luck..
     
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  19. JCinNC

    JCinNC Well-Known Member

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    Well at least it's not difficult. Lol.

    Any tests to confirm it has to be pulled? Teeing in gauges?

    Thanks for all the information.

    J.C.
     
  20. Delmer

    Delmer Senior Member

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    You've pretty well confirmed the governor is having no affect on the engine speed. Since it ran before and sounds like it mostly sat since then, it seems to me like it's gummed up rather than wore out. But I don't know the insides of this and what does what, what little bit could break at any second and lock up the fuel delivery like that.

    You could run it off a temporary tank, and tee in a vacuum/pressure gauge in the pump inlet, but even the worst plugged tank would let the injection pump idle down, and rev a little before it dies. I'd still run some biodiesel or ATF and let it run. The heat, vibration and chemical have a chance to loosen it up if it's not broken already, however slim a chance that is.