Multifuel Deuce, M35/ 5 ton surge troubleshooting

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  • čas přidán 7. 09. 2024
  • A guide to troubleshooting a surging idle problem on multifuel equipped trucks, as well as a brief description of how some of the fuel system works.

Komentáře • 36

  • @gordonjohnson405
    @gordonjohnson405 Před 3 lety +1

    My m35a2c idled like a dream until two months ago. Changed the gasket on the shut-off cover, which leaked after replacing HH o-rings two years ago. Then, on a trip to pick up compost. Coming to the nursery was fine. But, on leaving the problem appeared.
    It didn't fire up, or keep running without my foot on the pedal.
    I've so far drained and cleaned and disinfected the tank, lift pump screen, removed and cleaned the lift pump feed tube. I flushed the copper line, changed all filters, and thoroughly cleaned the housings.
    I replaced the rest of the tubing from the secondary and final filters, not previously done during FDC bypass.
    I noticed that the pressure relief valve on the filter housing is not a mild steel chamfered cylinder with a hole... It's a ball-bearing. But otherwise everything there is clean.
    I removed and cleaned the feed-port from the mechanical pump, and replaced the O-Ring. Never jacked up the engine before and hesitant to do it. From that position I couldn't stick anything in there to pull the fiber disk or spring.
    The problem is two things: keeping it running when braking to a stop, and a surge when I use the hand-throttle to do that.
    I can make it idle somewhat steady at 1500rpm or higher with the hand throttle. But if the rpms drop lower, then they drop slowly until about 1100rpm, then it shuts off. Any tap on the pedal once the rpms begin to fall results in a surge to around 2k rpms before beginning to fall again.
    I thought the hand throttle was slipping...but now not so sure.
    Maybe two problems? Air leak and debris in the mech pump or HH?
    Don't know how to find the air leak.
    Oh, and the shut-off cover still leaks...unless it could be the base of the HH?
    Not sure what to do next.
    Was thinking of putting a 4x4 on my jack to catch the edge of the front engine mounts, undoing the two nuts, and seeing if I could lift the motor enough to pull the lift pump... Then maybe HH O-rings again + disassembly and cleaning?

    • @tacticalrepair
      @tacticalrepair  Před 3 lety +2

      Sounds to me like a hard component failure in the mechanical governor assembly. You've done a good job checking everything, but unfortunately sometimes the injection pump just needs to go into the pump shop.

    • @gordonjohnson405
      @gordonjohnson405 Před 3 lety +1

      @@tacticalrepair Thanks, but...Argh! IPs are not cheap. C&C Equipment has one. But I think maybe I will eliminate the other choices. I think I will assume that it is the boost pump, until I have done everything there. If not that, then I suppose maybe a piece of debris from changing the gasket might have gotten caught in the overflow valve. So I'll disassemble and check it. And if not that, then maybe debris from the gasket change got caught in the Fuel Control Unit Assembly. Or maybe the plunger spring broke or became too weak for a full stroke. If I am in there I should be able to put some calipers on the plunger to compare with TM specs. 'Course if spring or plunger is bad my only real choice is to buy a whole HH for $500. And if the governor springs are bad, I might call AMBAC... But more likely I'll be the proud new owner of a $1800 reman IP.

    • @tacticalrepair
      @tacticalrepair  Před 3 lety +2

      Yeah it might not be a spring either. Likely one of many other wearable components.

    • @gordonjohnson405
      @gordonjohnson405 Před 3 lety

      @@tacticalrepair Well, had a rain free chance to look into it, and found a clue.
      Under the shut-off cover, the shut-off lever is at the 4 o'clock position. It moves freely. But where the spring in the governor used to return it to 7 o'clock fueling position, it now returns it to the 4 o'clock shut-off position. So while I only have the limited pictures from the TM to go by, yeah, I'd say you called it. There is something broken in the governor.
      But here's the question, are governor parts still available? Is an injection shop going to be able to fix it? Or should I get a new/rebuilt pump while I can, and hope it lasts?

  • @jimrobinson1745
    @jimrobinson1745 Před 3 lety +1

    Fantastic Video thank you so much. I am new to deuces . My M185A3 surges when idle up and down . After this i will start with lift pump and filters hopefully get it sorted. I am in Australia so not much info here so thank you

  • @bt7577
    @bt7577 Před 5 lety +1

    Hi, im a bit new to m35a2's. Having starting issues, engine was replaced with new in 89 and as far as i can see everything is stock and untouched. when starting i have to give a bit of gas with the hand throttle until it warms up (which raises the rpm) before i can release the hand throttle. i feel like mine runs a bit rough and lacking a bit of power. the in tank fuel pump runs 6.5psi. changed all filters. fuel lines dont leak. any suggestions before i start whizzing in the wind and pulling bits off to have a poke around inside? thanks (btw im in the uk!) Ben

    • @tacticalrepair
      @tacticalrepair  Před 5 lety +1

      You very likely have some varnish deposits in the injection pump. I would remove the hydraulic head, clean it and the associated parts, replace the o-rings, then see how it runs. You probably have just as much varnish in each injector. You can try to disassemble and clean them yourself or bring them to a professional shop, but they will need cleaning.
      You can also try running A mixture of 25 gallons of gasoline with two gallons of automatic transmission fluid.

  • @chandlergilbertson5902

    Very awesome and explanatory video. My deuce has a very lovey idle until it warms up for a bit. It’s a pretty quick lope on cold starts. Any problems I should look for?

  • @matthewjones8620
    @matthewjones8620 Před 6 lety

    I have several other trucks with Detroits in them so a few years ago I removed all the Deuce fuel filters and installed a homemade bracket hung off the oil pan bolts which I mounted a Detroit primary and secondary fuel filter with water separator for 3 reasons, better filtration, spin on filters located in an easy and quick location to get too, and its alot easier to keep inventory when all of my trucks run the same filters. My question, I didn't realize there was a pressure relief valve on the Deuce filter head, so I apparently don't have a pressure relief valve on the truck now. Do you feel this will be a problem? If so what psi pressure relief valve should I order and plumb into my setup? Again I really enjoy your video's. Thanks Matthew

    • @tacticalrepair
      @tacticalrepair  Před 6 lety +1

      Matthew Jones
      It really isn't necessary. It was more of a safety feature to keep the old canister filter seals from blowing if a filter became clogged.

    • @matthewjones8620
      @matthewjones8620 Před 6 lety

      Tactical Repair THANKS

  • @conniemccann1343
    @conniemccann1343 Před 5 lety

    My lds-465 fuel metering plate is stuck to the shaft. What can I do to fix this without damaging it?

    • @tacticalrepair
      @tacticalrepair  Před 5 lety +1

      Apply copious amounts of kroil penetrating oil, push the whole plunger and fuel plate up as far as it will go, put a screwdriver under the fuel plate and release pressure off the plunger, then use a tool to turn the gear. You can do this up and down until it is free. It should move absolutely effortlessly.

    • @conniemccann1343
      @conniemccann1343 Před 5 lety

      Have you got a video on this particular issue?

    • @tacticalrepair
      @tacticalrepair  Před 5 lety +1

      @@conniemccann1343 I think it is in one of my injector pump videos on here. Not sure which one.

    • @conniemccann1343
      @conniemccann1343 Před 5 lety +1

      I’ve had pb blaster on this for a couple of days! It’s almost like it’s one piece, but I know it’s not! I’ll take Kroil to it! BTW, thank you for your time and help!

    • @tacticalrepair
      @tacticalrepair  Před 5 lety +1

      @@conniemccann1343 just soaking it isn't going to work. You need to do the procedure I described while you have oil on it. Once you get something under or on top of the fuel plate, you need to force the plunger the opposite direction. If you have the plunger held up, you can remove the 3/4" center bolt in the top of the head and use a small hammer and punch ( preferably brass) to tap the plunger down. This will move it but it won't free completely until you work it up, down, and around a bit with a lot of kroil. I say kroil because it has solvents in it that break the varnish down.

  • @jasoncarter8784
    @jasoncarter8784 Před 5 lety +1

    I have be working on a 465 ltd on and off for several months. It has sat for several years at a local gun shop. I'm a professional diesel mechanic and I can't quite figure this one out. Tank was filthy. Removed and clean. Replace the in tank pump. Replaced oil and fuel filters. Removed and cleaned HH. I have gotten the engine to start and run for about a minute then it dies. I have about 6 psi fuel at the tank and 0 psi at the secondary bleed off port. Any suggestions would be greatly appreciated!

    • @tacticalrepair
      @tacticalrepair  Před 5 lety +1

      Check for obstruction between the primary fuel filter and the boost pump. The copper line that crosses the crossmember is a common suspect as it gets pinched shut easily. You did change the primary filter, right? No offense, but people often miss it. Right under the alternator.

    • @jasoncarter8784
      @jasoncarter8784 Před 5 lety +1

      @@tacticalrepair Yes replaced primary. Even went back and checked it for debris. I did blow air through the copper line from transfer pump back to the primary with filter off. Plenty of air flow. Did not look for a pinch in the line. Plenty of fuel flow from the inlet line into the secondary filter. Took that line off and put in bucket and turned on the ignition. I will check the copper line in a few days when I get back to it.

    • @tacticalrepair
      @tacticalrepair  Před 5 lety +1

      If you have fuel flow at the secondary filter inlet then a crushed line isn't the issue. Either a port in the filter head is plugged or the bleed screw is plugged or defective.

    • @jasoncarter8784
      @jasoncarter8784 Před 5 lety +1

      @@tacticalrepair I have tried starting with and without the bleed back check valve in place with the same result. With the check valve out will fuel just head straight back to the tank? I had the filter base off this week and blew air through it as well. I may have missed something there. Everything seems to be correct except for pressure past the transfer pump. I was checking the pressure at the bleed screw between secondary and final filter. Again thank you for the advice and your videos are great very informative!

    • @tacticalrepair
      @tacticalrepair  Před 5 lety +1

      @@jasoncarter8784 sounds like the bypass in the boost pump may have an issue. Or maybe you just haven't given it enough time to purge the air.