Discussion:
42- 6FGU25 missing and sputtering

We have a customer's Toyota 42-6FGU25, frame # 68662 equipped with a 4Y and a duel fuel ("convertible" in Toyota speak) that gives us diagnosis problems. It has approximately 8000 engine hours. When the operator drives across the yard at full speed, pedal to the metal so to speak, the truck will run fine for a short period of time then start to sputter and lose power and sometimes completely stall. If you shut down the machine for a few minutes it will start right up as if nothing was wrong. We know that the machine does this when the operating temperature is normal but we as yet do not know if it does it when the engine is "cold". We have done the obvious stuff, tune up with plugs wires cap and rotor. As well we installed a new regulator. We also have spent a lot of time on "adjustments" particularly on the dual fuel carb. Has anyone else experienced such a situation? I'm looking for advice on what the next thing we should look at. I have also posted the same question in the Mechanical discussion forum.
  • Posted 30 Jul 2011 00:26
  • By chickenbone
  • joined 28 Aug'08 - 28 messages
  • Ontario, Canada
Everyone has a friend in the forklift business!!
Showing items 1 - 20 of 20 results.
put a coil in it, its getting hot and breaking down. Shutting it off for just a couple of minutes is all it needs to cool off a degree or two and thats all an electrical component needs. If it were valves it would need a lot longer cool down time to make a difference.
  • Posted 18 Aug 2011 02:58
  • By bigGlittlestar
  • joined 12 Aug'08 - 139 messages
  • United States
thank you
  • Posted 18 Aug 2011 01:39
  • By 7777
  • joined 8 Mar'11 - 649 messages
  • New York, United States
All posters. Please bear with me until we have some more definative answers. In the meantime THANKS to everone for the positive feed back. I promise to report what it was.
  • Posted 18 Aug 2011 01:29
  • By chickenbone
  • joined 28 Aug'08 - 28 messages
  • Ontario, Canada
Everyone has a friend in the forklift business!!
try using OEM wires set. SMH use poor wiring Let Me Know!!!
  • Posted 16 Aug 2011 01:53
  • By LOGIC
  • joined 6 Dec'08 - 70 messages
  • Ontario, Canada
I just had one doing the same thing and this time it was the distributor coil acting up when it got warm. Replaced the distributor and truck runs great.
  • Posted 11 Aug 2011 12:08
  • By rogeriwt
  • joined 10 Apr'07 - 323 messages
  • Massachusetts, United States
Check the wires at your dist assy. Could be shaking loose when bounce across the yard
  • Posted 6 Aug 2011 05:02
  • By Prentice
  • joined 25 Jun'08 - 600 messages
  • Ontario, Canada
chickenbone ,having more than a cold one, work hard play hard lol
  • Posted 3 Aug 2011 09:15
  • By towmotor
  • joined 19 Feb'07 - 360 messages
  • Ontario, Canada
Check Governor RPMs. SB on weak valve springs. Hold throttle to floor Gov. specs. Hold tilt lever in hyd bypass unit starts to act up.
  • Posted 2 Aug 2011 12:04
  • By electrotech1
  • joined 7 Jun'11 - 4 messages
  • Missouri, United States
We haven't had a chance to discuss options with customer. Also today the first monday in august is a holiday. I know all you Americans are at work today, but we're having a cold one.
  • Posted 2 Aug 2011 06:24
  • By chickenbone
  • joined 28 Aug'08 - 28 messages
  • Ontario, Canada
Everyone has a friend in the forklift business!!
Did you find the problem yet?
  • Posted 2 Aug 2011 05:56
  • By 7777
  • joined 8 Mar'11 - 649 messages
  • New York, United States
but a can of sea foam , run in through the intake
  • Posted 31 Jul 2011 09:31
  • By towmotor
  • joined 19 Feb'07 - 360 messages
  • Ontario, Canada
I had one that had a broke choke shaft. It would close the choke under full acceleration. It too me a while to figure it out. May be worth a look.
  • Posted 31 Jul 2011 04:29
  • By rogeriwt
  • joined 10 Apr'07 - 323 messages
  • Massachusetts, United States
valve job
  • Posted 30 Jul 2011 23:41
  • By toyzilla
  • joined 29 Mar'10 - 175 messages
  • Texas, United States
easier to ask forgiveness than to ask permission.
Now that you mention it our tech said that it sounded like the valves were "floating". Is there a fix for the "valve problem" ?? Shim the rocker arm? Replace or recondition the head?? Or is this something you just have to live with?
  • Posted 30 Jul 2011 17:47
  • By chickenbone
  • joined 28 Aug'08 - 28 messages
  • Ontario, Canada
Everyone has a friend in the forklift business!!
you are experiencing a valve problem. they are recessed into the head and when the lifters get "pumped up" the valves stay open. when you shut down they pressure drops and process starts over. to confirm you can shim the rocker arm, don't block the oil passage. one of the symptoms that may be present that will con firm the valve issue would be the loss of compression sound when you immediately try to restart at time of failure. this was a common problem with some six series units. i think the consensus was excessive valve spring strength.
  • Posted 30 Jul 2011 11:03
  • By toyzilla
  • joined 29 Mar'10 - 175 messages
  • Texas, United States
easier to ask forgiveness than to ask permission.
It definatly runs on a proper 33.33LB tank. The tank orientation issue is something we will look at, as well as the suggestions by the other respondance.
  • Posted 30 Jul 2011 08:59
  • By chickenbone
  • joined 28 Aug'08 - 28 messages
  • Ontario, Canada
Everyone has a friend in the forklift business!!
If it's doing this on LPG is the tank valve opened FULLY and is the tank oriented in the correct position so the draw tube in it is at the bottom, had a simislar problem a while back,operator was just "cracking" the valve open a little and they were not putting the tank in the right position to get full use of its capacity, also had one customer who was running a truck off of a barbecue grill tank and wondering why it wasnt running right
  • Posted 30 Jul 2011 08:07
  • By kevin_t
  • joined 2 Dec'10 - 1,301 messages
  • Pennsylvania, United States
It rarely runs on gasoline. The sputtering happens on LPG
  • Posted 30 Jul 2011 07:41
  • By chickenbone
  • joined 28 Aug'08 - 28 messages
  • Ontario, Canada
Everyone has a friend in the forklift business!!
Does it do this while running on propane, gas, or both? Sounds like a fuel filter problem.
  • Posted 30 Jul 2011 06:08
  • By mrfixit
  • joined 11 Dec'08 - 1,434 messages
  • New York, United States
Dont know for sure, but you could have a bad coil inside the dist.
  • Posted 30 Jul 2011 05:25
  • By 7777
  • joined 8 Mar'11 - 649 messages
  • New York, United States

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