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Big Dog
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Posts posted by steeler

  1. This crap is just ridiculous. In my case, I spent probably 4 hours diagnosing, checking, rechecking, because a freaking brand new fuel line wasn't manufactured properly. Plus the time to change it, which is a bit of a pain in the ass on a nasty leu garbage truck. And that's time you really aren't getting paid for.

  2. Update......found the problem. The fuel line that goes from filter head to engine had a brass T fitting in it with a small line running to the after treatment fuel pump. I replaced the line with a new one and they didn't drill all the way thru the fitting. Parts defect. Sure is aggravating!

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  3. I've got a 2011 mp7 that we replaced the engine with a reman due to gear train failure. Trying to start the engine for the first time and I'm getting no fuel to the head. Weird thing is I've got 97 pounds of fuel pressure, engine will start, stumble around on maybe 3 cylinders then die.

    Now if I pump the hand primer, fuel will flow backwards, into the head from the front, nothing going in from the rear.

    All the fuel lines are routed correctly. Could a stuck check valve cause this? I know there are several in the filter head.


  4. I've talked to a few owners that have done it and are happy.

    There are downsides to it though. For example I just finished working on a KW with a Paccar engine that was deleted. Guy had taken it to a dealer who refused to work on it because it was deleted. Turned out the ecm was fried. We got him a new ecm, but our local dealer would obviously only program it with the factory program. This guy is from out of town, and the company that deleted it for him is 1200 miles away, and out of business.

    So, he will have to find somebody to put his delete software back in it. In the meantime though, his truck will progressively derate. 

  5. 6 hours ago, mackr1989 said:

    terminology was wrong when they were saying the synchros were bad. the clutches were worn amongst other things. $5200 was the cost of the reman.

    Damn. You don't see sliding clutches worn out in a Mack trans very often. They can take a lot of abuse and still function just fine. Unless someone was VERY abusive to it, or whoever looked at it doesn't have much experience diagnosing them.

  6. 12 minutes ago, Mackpro said:

    FMI 3 or 5 could be the harness end as Steeler said . FMI 7  with miss or running rough could be oil control valve stuck open or stuck engine brake plunger on rocker arm 

    Good catch. I should have said fmi 3 or 5. Not 7. Thanks.

  7. After an injector cup job, while adjusting valves, the plunger on #5 exhaust valve is sticking out a little more than the others. All others adjusted fine, but#5 has a much thinner shim under it, like someone had this issue last time.

    If I push down on the rocker arm, three is a little spring loaded feel to it, not anymore than the others had. Any reason this plunger is sticking out further?


  8. You should have a constant 12v at one wire of the fan solenoid, the other wire is a ground signal from the ecu to disengage the fan. It could be as simple as a blown fuse (don't quote me but #41 I think?) Or could be a break in either the hot wire or ground. 

    I've seen many that were broken wires, rather than chase the mess around and on top of the transmission, I just rewired, bypassing part of the harness.

    I don't have a schematic with me right now, but can give you pin numbers Monday if you still need them.


  9. 13 hours ago, turckster said:

    Aftertreatment fuel psi should be what.... 90ish psi? What test is it that you can not perform that requires a special tool?


    I was wrong on that test, all it was was checking the fuel pressure to the shutoff valve, which is the same as the engine pressure. That was the last test, so it just told me "no fault found". 

    I hooked up another truck of the same year just to compare pressures. That one had an after treatment fuel pressure of 90 psi when the shutoff valve opens, then dropped to zero with the valve closed. Mine stays at about 45 with the valve closed. I'm going to run regulated shop air to the shutoff valve at 32 psi just to see if anything changes.

  10. Hey guys I've got a 2015 lei that is throwing a p20de00 after treatment fuel pressure sensor circuit range/performance fault.

    I've run through the diagnostics with tech tool with exception of the final test because I don't have the special tool to do it, but everything checks good. 

    The afp runs about the same as engine pressure when the shutoff valve activates, then runs about 45 lbs deactivated. Engine fuel pressure is steady at about 58-60.

    Any ideas?


    Forgot to add that I replaced the doser module. 

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