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Cat D5N Fule pressure light on at high RPM but not low RPM

lazyoaks ยท 2013-02-09 17:10

Hi, I'm just recently purchased a Cat D5N Dozer and I'm learning the ropes...complete newb here. When I run the dozer the fuel pressure light comes on after about 30 minutes of operation but will go dark on low RPM but come back on at higher RPM. I'm just getting into trouble shooting this problem and was wondering if I could gain some insight. Maybe a clogged fule valve? Thoughts? Any help is much appreciated.

Replies12
  1. #1Phill2013-02-09 17:56

    this may sound silly, but have you changed the fuel filters ?

  2. #2lazyoaks2013-02-09 19:08

    The seller said he had, I'm going to email him to double check. I suppose I forgot to mention, it was used and not new.

  3. #3Per Eriksson2013-02-10 07:25

    Don't bother emailing, replace them yourself, they are cheap and then you know 100% they are good.

  4. #4caterpillarmech2013-02-10 07:50

    The light comes on for fuel pressure differential. Yes, Change your fuel filters first.

  5. #5rivroshaun2013-02-10 18:57

    Well before you change the filters you might want to get an actual reading of your fuel pressure by connecting a analog gauge. But if you don't have the tool then yes change the filters. Don't forget to cut open the filters and do a visual inspection to see if there is any gunk. This could be a sign that bacteria is in the fuel system and it's a bitch to get out. Ask the previous owner if it sat for long periods of time with the fuel tank half empty. You might also want to check to see if you have any fuel leaks. And last I recoommend you do a SOS sample. This will tell you how healthy your fuel system is. A clogged fuel valve sounds like something that would cause some missfiring. Have you noticed any performance issues?

  6. #6lazyoaks2013-02-11 20:33

    Thanks guys, I really appreciate the advice. There are performance issues, when the light comes on the machine bogs down. I'll get back with results when I can follow these reccomendations.

  7. #7PAcattech2013-02-11 23:40

    Hi lazyoaks, What does the light coming on look like. I don't remember the D5N having a fuel filter warning light most Cat machines do not have a warning light for fuel filters. Some of the dumb pictures they put on those warning lights can be confusing maybe attach a picture .

  8. #8whitemike2013-02-12 14:20

    Is it possable to adjust D5N throttle position? Our's has the rocker switch and it is either at idle or full throttle, no inbetween. Surely it is supposed to be adjustable, right?

  9. #9Chisumtrail2013-02-12 21:14

    Not

  10. #10whitemike2013-02-13 18:57

    Thanks for clearing that up i will stop trying to set it. I have several pieces of tigercat logging equipment with a rocker throttle switch and you can set engine rpm's wherever. I just thought dozer the same. thanks again.

  11. #11Construct'O2013-02-13 20:09

    On my D6R Series III and D6N you push the throttle rocker switch to high idle, then declerate down to where you want your engine to run.Hold the rocker for like 10 seconds then release the rocker then take your foot off the declerator.It should lock the high idle to what you had it set for the rpm that you want to use. If you have to idle it down to get off the mcahine for any reason then you have to reset it.At least that is how mine works.Good luck

  12. #12whitemike2013-02-13 22:06

    Now we getting somewhere, i was thinking it had to be possable to adjust engine rpm. Because i will be honest with you, when i am finish gradeing i make a mess if i run to fast, but holding deacellerator for several hours wears my legout. Plus you can save a gallon of fuel an hour possably. Thank you sir