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Big Dog
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Posts posted by steeler

  1. Kinda off topic here but we do quite a bit of work on paccar engines. You wanna talk about an SCR nightmare, wow.

    I had one with a def quality fault that just would not clear. I threw everything under the sun at it, nox sensors, def doser, new def fluid, dpf filter, catalyst, 7th injector, countless hours of troubleshooting and test driving all to no avail.

    Ended up opening a case with paccar engineers and after several regens and 2 40 mile test drives that had to be recorded and send to them, they simply gave me 24 hour special access to a feature in the software that allowed me to clear the code out.

    I mean really? After all that, it was that easy? I wish they'd give me that special button permanently!

    The truck worked fine after that for about a year, then the same crap started again. The customer said screw it and had it deleted, and I don't blame em.

    • Like 1

  2. Ok after going thru it all again, I can disregard that 33 fault code. I was using a pro link and had the vmac1 cartridge in it. I hooked up the laptop and it's actually a 32, for the rpm sensor. I've eliminated the wiring and sensor, so I believe they have the wrong flywheel in it.

    I don't know who was working on it before but damn, let's just say he was a hack.

    Sad thing is, I'll probably never know what the outcome is. The only reason it's at my shop is because nobody else could figure it out, so the customer is going to pull the flywheel out himself.


  3. 16 minutes ago, Mackpro said:

    Mack came  out with a conversion kit to replace the  two VMAC 1 ECM’s  with a single VMAC 2 ECM . The wiring harness on the engine remained the same as original. Chances are the one of the original VMAC 1 ECM’s failed and the conversion kits was installed. 

    Hmm. Interesting. Ya everything I'm looking at other than the module screams vmac 1. But I checked the vin and it is coming up as vmac2. The pump part number is correct.

    I got more info on this truck. I noticed it has a new clutch and flywheel somebody else put in. I'm now suspecting they may have the wrong flywheel and the rpm sensor is not reading it.

    The engine will die if I unplug the tem at the pump, but runs the same with the rpm sensor unplugged. That tells me I've got something fishy going on with the rpm sensor. It's supposed to ohm at 200-300, but I've got 180. It's a PAI sensor, I'm going to put a Mack sensor in it and see what happens.

  4. 20 minutes ago, Mackpro said:

    Here’s the easiest way to tell a VMAC 1 from a 2  on a CH style truck .  A VMAC 1 has the engine harness plug iinto the firewall right above the windshield washer fluid jug on the passenger side of the firewall. On a VMAC 2 truck , there is a block off plate above the windshield washer fluid jug . Also  , the Econ-Vance is a lot longer on a VMAC 2  and the injection pump almost touches the air compressor, and  of course the VMAC 3 is an ETECH  style engine with the heat shielding  over the individual injector pumps 

    Thanks pro. I'm not with the truck right now but I do know there is a bulkhead harness going into the firewall on the passenger side. I remember that was how I could always tell a 1 from 2, but I couldn't remember which was which.

    So, sounds like a 1, so why does my module have a vmac 2 sticker on it? Didn't the 1s have an fic module?

  5. 1 minute ago, Ahubbard said:

    Yes I will get that feeling when I drive. Almost feels like the spring is too light on the throttle return even though it’s not. I will let my foot of the throttle some and lay back in to correct that sometimes.

    When this does it at 1200 it almost is like a horse galloping. Rhythmic and kinda shakes the motor.

    Sent from my iPhone using Tapatalk

    Yup sure sounds like resonant ride. Unfortunately I'm not sure there's much you can do to fix it. We've sent pumps out before, some were better, most weren't. I'll do some digging about that contraption Mack came out with.

    Maybe someone else here knows of a fix?

  6. Yes, resonant ride in the pump feels kinda like the fuel rack in the pump is bouncing back and forth, usually right around that rpm. 

    I remember it being a big pain in the ass in the early/mid 90s at the dealership I worked at. Sent out many pumps for this problem, but rarely was it ever fixed.

    I remember Mack coming out with some kind of contraption that mounted to the front of the pump to fix it, but man its been a long time!

    Does yours almost feel like you are bouncing the throttle real fast at that rpm? 

    And usually if the engine had a strain on it, you wouldn't feel it. Only happens when there is steady rpm with little to no strain on the engine.

  7. Hi all. I've got a ch dump I'm working on that has a coughing/stumble mainly noticeable at idle. I have a 33 fault code. My vmac 1 book shows the 33 as injection pump speed sensor. My vmac 2 book doesn't show a 33 at all.

    Now it's been awhile for me since I don't see many of these older trucks anymore. The module in the cab is a vmac 2 module, but the customer has put a different engine in the truck, that's when this issue started. Is it possible that I have the wrong injection pump because of the wrong engine? Would everything plug in the same on 1 vs 2. 

    Like I said, I'm big time out of practice on the older vmacs.

  8. 11 hours ago, fjh said:

    Yup seen it happen a few times ! It even happened when it was a not Swedish owned ! How ever these guys can't really afford  need to piss many more people off,small or big! Volvo/ Mack  market share is dropping like a stone!

    Yup, Volvo sure has trashed Mack in my opinion. I mean, what's really left that is actually Mack? Transmission I guess, some suspension? They have even managed to screw up the diffs. Sad.

  9. On 6/5/2017 at 3:23 PM, Keffer inc said:

    I'm still in Amarillo Tx, Friday they completed the cam, injectors, and dpf. We went for a test drive and it was still missing badly, maybe even worse. At first they were thinking maybe a valve was damaged inside the head. But Saturday a tech decided that it may have been a fault injector that they got. Haven't heard anything yet but I hope that's it. I've been at a hotel for a solid week now.

    Glad it was only the injectors!

    A couple months ago I did a cam on an mp8 with only 200k. 

  10. 2 hours ago, mackcat12 said:

    fjh you are right I talked to the former service manager at my dealership and he said if i was a huge company they would have already replaced my truck no questions asked

    Oh ya, for sure. We do a lot of work for a nationwide garbage company. When we have issues, they make one call to Mack corporate and things happen. I feel bad for the small guys.

  11. Wow. Just catching up on this thread, what a mess!

    When they replaced the engine, I assume it was just a basic that required all of your external components to be swapped to the new (reman I'm sure) engine? So you've still got the same egr cooler/turbo and all that?

    Theres a guy around here that back in the 90s had several trucks, they had braking issues. At the time I worked at the dealership and this guy fought this problem for probably a year as we threw every valve, shoe, drums, whatever Mack told us to throw at it we did.

    Never did fix the problem and Mack refused to give the guy new trucks. These were cl's. He ended up suing Mack over it, I don't think he got squat.

    The 2 trucks he was having the problem with he parked in a barn while the lawsuit was ongoing, several years.

    He never bought another Mack. And this is when they were solid trucks, not Volvos with a dog on the hood.

    Good luck to you man!

    • Like 1

  12. 12 hours ago, Mack Technician said:

    The 8888.... number at bottom of screen is a bag with replacement swag bits. If you see VOE on the box that is a “Volvo Original Equipment” number. That means it was cheaper to buy from Volvo. If you want the numbers Grab it since I have to erase pics soon, too little storage left. If you give Mack the Volvo number of any of these their system will automatically supersede to a Mack #. 

    Thank you!

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