Forum Discussion

Lar_s's avatar
Lar_s
Explorer
Mar 14, 2014

New Turbo on - still sluggish on hills - fuel?

OK, took forever to locate and get a new turbo, had that installed, road tested with the computer and all seems well. Unfortunately, it's still sluggish on hills.

If you've followed this thread I've also got algae or bacteria growing in the tank, though you'd think with 0 and below temps they'd hibernate. I changed both fuel filters 100 miles ago and the fuel looks clean in the plastic see through cup, though when I changed them, the inside part of the filter contained a dark matter (bacteria ?) Could this be enough to make it really sluggish on hills? I charged the tank with biocide, though perhaps not enough. Should I recharge the tank and change to new filters?

I've also changed the air filter 100 miles ago. No black smoke out of the exhaust.

BTW, the turbo only had chips out of the cold side, the hot side looked good.

Advice please.
  • C-Leigh_Racing's avatar
    C-Leigh_Racing
    Explorer
    Mar 17, 2014
    You know, Airstreamer may be on to something. Take theses kids getting a diesel pickup, first thing they do is new exhaust & big air intake system, cause a diesel will suck up some air, way more than a gas engine, so check the filter & intake tubes to make sure they not getting sucked flat & restricting air flow.

    I know an old Ford 7.3 diesel pickup, you let the filter get a little dirty & it will cause the intake tubes to suck flat when you rev the engine up.
    Neil
  • dougmac's avatar
    dougmac
    Explorer
    Mar 16, 2014
    Do you know if your ISL has a common rail or a caps fuel system? An '04 could have had either system.
  • Airstreamer67's avatar
    Airstreamer67
    Explorer
    Mar 16, 2014
    Quote: "Agree with oil test. Maybe I can siphon some out and send it in."

    The best time to send in the oil sample for analysis is when it is being changed after many miles on it. This will allow any problems to show up.

    Best of luck with your problem.

    By the way, if microbes are the reason for the power loss, it will probably show up as low fuel pressure. If you can get a fuel pressure gauge installed on your rig and compare the fuel pressure under load with design parameters, you will be able to tell if there is an obstruction in the system from the microbes or bad fuel pump or whatever.
  • RayChez's avatar
    RayChez
    Explorer
    Mar 16, 2014
    I also noticed loss of power on my 3126-E Caterpillar engine. I was wondering if maybe I had a exhaust leak because when I first start the coach I can here something like a tappet clicking or maybe an exhaust leak. I have been wondering how I can tell which it is.
    I did change the fuel filter and the air filters when I got back from that trip. I have not used the coach since then so I am not sure if I got the power back. But I am still concerned about the clicking. It is hard to tell the difference between a lose tappet and an exhaust leak. Any thoughts on what to look for if it is a exhaust leak.

    On a 7 percent grade about a mile long by the time I got to the top I was only doing 15 mph with the pedal to the medal.:S
  • Lar_s's avatar
    Lar_s
    Explorer
    Mar 15, 2014
    No dino test yet. The air cleaner was really clogged because it had been in the body shop due to hitting a deer mid day in Alabama last winter.. I was not pleased to see all the crud and I'm pretty sure that was what caused the turbo problems, though I can't prove it.

    Monday I'll see about the tank pull and cleaning. Still not sure about fuel polishing in this area. Weather isn't cooperating as far as changing filters and road testing right now.

    Agree with oil test. Maybe I can siphon some out and send it in.

    Thx
  • CA_Traveler's avatar
    CA_Traveler
    Explorer III
    Mar 15, 2014
    Bill.Satellite wrote:
    I have struggled with that issue with a Detroit 8V92 DDEC I for too many years. I am sure it's a wiring issue as everything else has been checked and the engine was even replaced. No matter, I still have no power when it counts. Run down the road at 75 all day long....climb a hill at 25-40 MPH when I used to climb the hills and pass all the 18-wheelers!
    Prevost will not help and Detroit will not help so we just keep plugging away at any suggestion from anyone anywhere hoping someone will trip over the actual solution.
    Have you had it checked on a dynamometer to see if it shows up vs on a grade?
  • Airstreamer67's avatar
    Airstreamer67
    Explorer
    Mar 15, 2014
    The wear on your replaced turbo could indicate a problem with the air cleaner, which could also produce wear on other engine parts such as rings, etc. and lead to reduced power levels. Such wear would show up on the cold side of the turbo, not the hot side.

    I would make sure the air cleaner and its related tubing and connections are in good shape and not leaking. Also, an oil sample sent to Blackstone Labs at your next oil change can tell you of any such problems for about 30 bucks.
  • Lar_s's avatar
    Lar_s
    Explorer
    Mar 15, 2014
    Still in the frozen 4' of snow north up here so moving slow on this project. I think it's probably right that I'll have to have the tank pulled, cleaned and re-installed. Don't think anybody up here does fuel polishing. The project continues.

    Thx for all the imput.
  • MM49's avatar
    MM49
    Explorer
    Mar 15, 2014
    When you have the bio problem in the tank cleaners will initially make the problem worse by loosening all the gunk up. The result will be the fuel pick of screen in the tank will clog. The growth is biological. Have the tank removed and steam cleaned. Do the same for the fuel sock assembly, fuel heater and pick up filters. Not an easy project.
    MM49

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