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CAT 613G fuel issue

CAT ONLY ยท 2012-09-26 23:20

Problem this scraper has is almost No fuel pressure. Engine is a c6.6 all fuel filters where replaced, intake and exhaust systems checked for restriction, system has flow from tank all the way to the fuel transfer pump but only builds about 9psi during cranking. The relieve valve at the fuel rail was replaced and didnt help. Cranking speed is at spec. Both primary and secondary engine speed sensor signals within spec. Has anyone come across this issue before?

Replies7
  1. #1Bob/Ont2012-09-27 11:19

    Tell me a bit more about your engine. Is it a HUEI system? Later Bob

  2. #2CAT ONLY2012-09-27 20:29

    its a common rail, i replaced the injection pump (includes transfer pump) and it fired up first try! i would love to take the pump apart and see what exactly happen inside of it, but its a core so taking it apart isnt a good idea

  3. #3Bob/Ont2012-09-27 20:52

    Very Good.I think you have 3116 or modern version mechanical injectors. If so what you changed was the transfer pump and governer. You where wise to not take it apart. Very complicated and hard to figure out from looking at it. It is more likely linkage wear than low fuel pressure caused the problem. If you had a newer one HUEI they are sensitive to oil viscosity. They have a plug in the harness to change if you change viscocity of oil. An oil change solves many hard starts in winter. Later Bob

  4. #4PAcattech2012-09-27 21:20

    Bob a c6.6 in catonlys machine machine is not a Heui system its a common rail the pump he is refering to is the high pressure fuel pump they have no govenor all electronic controlled

  5. #5CAT ONLY2012-09-28 00:05

    Correct, when the tractor came in it would only build about 10psi fuel rail pressure at around 150rpm cranking speed, i believe the desired fuel pressure displayed on the engine ecm status page (through ET) was 4000psi + with the new pump the fuel pressure is right on the money! Now working on a 420F backhoe that has 8hrs on it and is throwing codes for the DPF soot sensing module.

  6. #6Bob/Ont2012-09-28 08:39

    Okay, that's a bit modern for me, thanks. Later Bob

  7. #7caterpillarmech2012-10-21 08:36

    I was going to say, As long as you have transfer pump pressure and no rail pressure. Your pump is done. These new pumps are very touchy when it comes to water and debris in fuel.