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Randy_A's avatar
Randy_A
Explorer
Jun 14, 2015

Cat C7 starts, idles, but won't rev up in gear.

I have a 2005 Fleetwood Excursion on a Freightliner XC chassis with a 350 hp Cat C7. I drove it about 40 miles two weeks ago and it ran fine, accelerated good and ran 55-60 on the highway no problem. Yesterday I started it up tried to back out of my driveway and it would not make it up the small grade. It started easy, idles good, and will rev up when in neutral, but when in gear, forward or reverse, the throttle pedal goes down and nothing. I thought maybe it was fuel filters so I changed them this morning, no change. Any help would be greatly appreciated.
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  • Randy_A's avatar
    Randy_A
    Explorer
    Jun 14, 2015
    1. Plenty warm. Normal on guage.
    2. No codes or check engine light.
    3. Air is up front and rear.
    4. Fuel filters are new.
    5. In limp mode you still have enough power to move the moho.
  • rgatijnet1's avatar
    rgatijnet1
    Explorer III
    Jun 14, 2015
    Sounds like it is receiving some information from one of the sensors that is putting the engine in to limp mode.
  • Big_Katuna's avatar
    Big_Katuna
    Explorer II
    Jun 14, 2015
    No code-check engine? Are you sure a brake isn't dragging? Maybe time to buy a Silver Leaf setup for your laptop.
  • Ivylog's avatar
    Ivylog
    Explorer III
    Jun 14, 2015
    I had a MH in my CG with the similar problem on a Cat engine. I forget now which sensor's plug (near the fan) was dirty and cleaning it solved his problem. May take hooking it up to a computer to see which sensor is not working correctly or try cleaning all of the two wire connectors you can get to.
    A Cat/Allison will do the same thing until it warms up but doubt it's cold enough for it to do that. Worth giving it more time to warm up and see if it will accelerate after a couple minutes.

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