Heavy Equipment Forums Heavy Equipment Community

Ex120-2 nightmare

Jmckinstrie · 2026-01-08 14:34

Hi all. I’m at my limits. Lost compression at some point in machine. Thought is was just a workout injection pump. Had that rebuilt. Still no start. Full rebuild with oem Isuzu parts. Liners kit. Bearings. Cam. Head work. You name it. Assemble it in my garage and fired it up on a cradle I built on a pallet. Didn’t run it long maybe 1 min. But it fired right up. Installed in machine. Bleed fuel lines again. Nothing. Turns over good fresh batteries. Just bellows white smoke. What the chance the hydro pump is causing an issue to cause a no start? The engine is 100% mechanical. Unfortunately no local shops will service or help and I’m usually that guy people call with questions. Please help with what ever you may think of. This machine is for personal use to build a home. I’m desperate to get my family moved. Thanks guys.

Replies19
  1. #1Jmckinstrie2026-01-08 16:23

    I’m gonna try running fuel line from the portable tank I used in garage to run engine. The machines tank is clean(can see the bottom) and the lines are new. I suppose there could be a restriction at the point of outlet on the tank but its flows fuel pretty good. Plus the when I crack the injector nuts it sprays all over.

  2. #2Simon C2026-01-08 23:58

    Does it have a grid heater or glow plugs? When you ran on stand was it full of water to top, Is there power to the glow plugs. Have you tried spraying WD40 very heavily into the air intake while cranking along with a heat gun or two shooting super hot air in at the same time? Lots will not start with out glow plugs. Oil into cylinders greatly increases compression. Try these things and let us know. Simon C

  3. #3Jmckinstrie2026-01-09 07:22

    Hi Simon. It was 20 degrees out when I bench started it. Almost 50 yesterday when I tried it in machine. I did pre heat the oil. Glow plug not hooked up. Fuel was cold. I’m not spraying anything into engine. I have over 6k in parts. I’d have to be hospitalized if it grenaded. lol. Further research has revealed the hydro pump is at full swash while cranking. Would make sense as why it fired on pallet with no load. I did work on pump as the previous owner hacked up the pump with that manual servo control kit. It only ran once after pump work was done. Kinda believe I been chasing the wrong problem since last year !

  4. #4HarleyHappy2026-01-09 09:17

    Think I’d be hooking up the glow plugs. I have some equipment that will only start with glow plugs, if it’s 50 degrees or colder. Understand you don’t wanna grenade motor but how does one have a hydraulic issue and that leads to a full engine overhaul and the hydraulics were never addressed? Thought in original post, you said it turns over good?

  5. #5Jmckinstrie2026-01-09 10:09

    Hi happy. Pure inexperience lead to an engine overhaul. I have tons of time on lots of equipment but multi spools valved equipment. Or better said ones that are pilot controlled. As I stated before previous owner hacked up hydro pump. I re installed valves and pvc computer as it was from factory. After that the engine never started. I assumed it was engine related as it had 9k of hours. Glad I rebuild it anyways as it was tired and out of spec. Not fully understanding how the pump is controlled , I would have never thought it was an issue. Welp it is. Pump is at full swash while starting and I believe that is keeping engine from starting. If a pump at full tilt can stall a running engine it can surely keep one from starting. Currently figuring out how to correct the full swash issue.

  6. #6HarleyHappy2026-01-09 11:13

    Have you tried releasing the pressure by moving something, while trying to start it. I would also recommend hooking up a jump pack, while doing it. Lately, I have been on a kick of installing remote jump posts on everything I own, making jumping and battery testing easier. Only have a skid steer left to do, where the damn battery is under the floor plate.

  7. #7Diesel Dave2026-01-09 11:46

    If all the spools in the main control valve are in neutral , even though the pump being in full swash should not prevent the engine (especially a fresh overhaul ) from starting. Hydraulic pump being in full swash is a very common issue with EX- 2, and -3 ‘s.

  8. #8Jmckinstrie2026-01-09 12:01

    So I got it started today. Confirm last night was in full swash via dr. Ex. At 24degree. No power at high speed valves. Applied power from jump pack no no 1 valve. Started right up! What the swash angle go from 24 to 2 very quickly. Have to give Jules(igonadigtochyna)in Canada a shout as he gave some great advise. Thanks.

  9. #9Chiefdug2026-01-09 14:26

    You mention white smoke! I may be wrong, but that sounds like lack of fuel to me. One place to look for a plugged fule line is on the the filter inlet/outlet lines. On the bolt that holds the fuel line on there is a small filter inside the bolt. (see pics)

  10. #10Jmckinstrie2026-01-09 16:29

    Hey chief. Got it going. Thanks for replying.

  11. #11Chiefdug2026-01-09 16:33

    Sounds good. We gotta keep these old girls going.

  12. #12Jmckinstrie2026-01-09 16:53

    Absolutely! As annoyed as I was over the last ten months I sure learned a lot. Made too many assumptions.

  13. #13Tones2026-01-09 17:13

    Testing is always cheaper than guessing. The best mistake to learn from is other people's, for this you have set a fine example and hope others learn. Top marks for perseverance and coming out the other side a winner even if the wallets lighter.

  14. #14pdeal2026-01-09 20:16

    i always tell myself in situations like this that education is never free. The bright side is that you got a new engine!

  15. #15Jmckinstrie2026-01-10 09:07

    my 5 and 7 year old boys worked with me too. Was also fun and rewarding for them. Cannot buy that kinda time with them. When I first fired it up in our shed my oldest gave me a huge hug. Damn near picked me off the ground. lol

  16. #16masterwelder2026-01-10 09:28

    I would of thought the Skid would of been the first one you did, not the last!

  17. #17Jmckinstrie2026-01-10 09:31

    The dang thing started with original engine with pump the same as it is now. Was never a thought the pump was an issue afterwards. Just got lucky it happened to start that day.

  18. #18Jmckinstrie2026-01-10 09:34

    I pickup a bunch of surplus military jumper’s. Complete overkill but neat.

  19. #19HarleyHappy2026-01-10 09:38

    Still trying to figure out how I want to do that. Its got the original cables back to the starter. Not sure if I want to cut the ground cable and redirect it or use a battery terminal shut off, and manufacture a forked rod through the floor plate to a milled key slot or a knob. Unfortunately my dog likes to ride on the plate and sit between my legs. Not really even sure where I would want the disconnect, if I relocated the ground cable.