Help Getting Home! Parked 15 yrs, Big Mountains.. '04 Mack MR688S, AI350

[mowerman]

20 hours ago, JoeH said:

Also not sure anyone's picked up on them, but those 2 dalmatians are good looking dogs!

Hell, I didn’t even notice the damn things I had to scroll back to see what you were talking about ha ha thanks for that but kind of following this. I really don’t have any advice, for this  guy. Oh, I could think of except for the obvious everybody has already brought up. Maybe the fuel pump was dried out too long damage. The pistons inside last one I bought was $2500 exchange and that was 40 years ago. 237 Maxidyne 

[terry]

5 hours ago, JoeH said:

Sounds like there's some unresolved lemon issues going on, it only lasted 16k miles on that rebuild til they got fed up with it. Hopefully some old timers on here will be able to chime in.  I'd get a hold of every Tech Service Bulletin you can get your hands on.

This engine should be CCRS which is Current Controlled Rate Shaping.  Basically the EUPs get fired in 2 phases, an initial one to start the burn and a second phase to complete the full injection quantity.  Pre CCRS trucks just fired the EUP in one shot. EUPs are not interchangeable. Heads are also different, the pre CCRS I believe used a leak off line from the heads, the CCRS do not.  

Sure alot different than the old simple two  valve mack engine! they would run forever with a little maintenence.   terry

Edited September 28 by terry

[JoeH]

In case I didn't mention it, the EUPs push over 24,000 psi through the metal lines going to the head.  DO NOT crack them to do cylinder cut out tests!! You will poison yourself with diesel fuel.  Instead, you just undo one of the wires going to the EUP by loosening the screw and pulling the eyelet off the screw head. Screws are not meant to come all the way out. You will likely get a spark, no big deal.  This will turn that EUP off, so you can see if said EUP is firing. If it doesn't affect the idle then it's not firing.

[tjc transport]

and you can get eup's that will not fire at cold idle, but work fine once the engine is warmed up, or rpm's are raised. 

i had one on the 05 427 like that.

[mrsmackpaul]

On 9/28/2024 at 6:10 AM, mrsmackpaul said:

If it was me I wouldn't worry about what any previous owner says may or may not be wrong 

I can understand the previous owner doesn't want any involvement, just get it off their place

It is no longer their problem, it is now your truck, your problem 

All of that been said, maybe think about getting a jerry can and some hose and just run your supply and return out of that

If you can make the truck run fine from that, you know the problem is in the tank or the hoses connected to the tank

 

Paul

 

 

This is may of come across a bit harsh

My point probably is badly made

I guess what Im trying to say is, this truck has been a issue for a long time and if the miles shown are correct it has been a problem for a long time

The truck needs a fresh set of eyes, your eyes and hands etc with and whole fresh approach

If you worry about what others have done before there's a real risk of repeating their mistakes and the truck becoming a white elephant for you as well

Your that fresh set of eye's 

If I were you I would assume nothing and methodically work through and prove each system, fuel, air, oil electrical and so is operating correctly  until you find the issue that has caused the truck to not of worked for over a decade

Just some thoughts that may or may not help

Keep at it and you'll get there

 

Paul

[JoeH]

3 hours ago, mrsmackpaul said:

This is may of come across a bit harsh

My point probably is badly made

I guess what Im trying to say is, this truck has been a issue for a long time and if the miles shown are correct it has been a problem for a long time

The truck needs a fresh set of eyes, your eyes and hands etc with and whole fresh approach

If you worry about what others have done before there's a real risk of repeating their mistakes and the truck becoming a white elephant for you as well

Your that fresh set of eye's 

If I were you I would assume nothing and methodically work through and prove each system, fuel, air, oil electrical and so is operating correctly  until you find the issue that has caused the truck to not of worked for over a decade

Just some thoughts that may or may not help

Keep at it and you'll get there

 

Paul

Words of wisdom right there. If the former owner knew what the problem was they would have fixed it.

Edited September 29 by JoeH

[alabamaslammer]

got back to the truck late this afternoon. first thing i did was take a look at the fuel tank vent. it is covered in junk but it should still work- it's crazy to me there is enough pressure in the tanks to push the springs on these things open. next i reconnected the batteries and plugged in my nexiq scanner. nothing. nexiq device tester worked and read all modules but vmac wouldn't connect. found a helpful post on bigmacktrucks.com noting the rocker switch next to the port - flipped the switch and voila - i was in. no active faults but there were 3 historical faults in july 2018 - are the vmac date/times usually correct or no? the blink codes were 6-4, 6-8 and 4-1. 6-4 is a j1939 issue - if the vecu or eecu loses connection to j1939 for more than one half second the code will set and electronic malfunction light will turn on. the fault will become inactive if communication resumes for at least one half second. when code is active, engine speed will default to 900 rpm (LIMP MODE). If communication is lost on both j1587 and j1939 the engine will not run. code 6-8 will set if vecu loses connection with allison hd transmission on 1939 line. code 6-8 can only be logged if the 'use j1939 tailshaft speed sensor' option is enabled in the vecu data file. code 6-8 will always be accompanied by a code 4-1 (loss of road speed signal). 

test 1. checking for code 6-8. verify code 6-8 is set. if code 6-8 is set, go to test 2. if 6-8 is not set, wiggle the harness and connectors to try to set the code. 

test 2. check for code 6-4. if fault code 6-4 is set (IT WAS), locate and repair the open circuit in the j1939 serial data line between the vecu and j1939 transmission connector. 

after checking the codes i ran some laps in the truck and it did much better than before. the electronic malfunction light did not turn on (it did come on intermittently when i drove truck a few weeks ago, tho not sure why those instances did not show in the fault logs unless the truck date/time is wrong?) i suspect the power service additive helped prevent filter clogging, which it says it does. i did many more laps with more power before finally losing power and truck dying a couple times and i called it a night after realizing my primer pump is seized and not wanting to use ether. at one point during one lap the truck was putting out a ton of gray smoke. seems like it burned up some junk or something. 

i got back to motel, showered and wrote up this post along with the vmac stuff detailed here. need to think about next steps. i have two 55 gallon oil drums (one is clean; one was clean but had dirty diesel in it from a different truck) and a transfer pump with brand new filter, 3 primary filters, 3 secondary filters, a fuel pump and my tools. not sure my path on the fuel stuff yet. radiator shop said they would pressure wash and dry tank for $130. they are 30 min drive away. friend quoted me 1500 to tow it home. lots of options. not sure what path we will take 

[mowerman]

Seems like if you’ve got the 1500 it would be a lot easier on you to get the thing home. Good luck.

[mowerman]

I had to put a clutch in my DM when I bought it. It was 40 miles from here then I drove at home. Didn’t have too much trouble… bob

[Geoff Weeks]

I second the tow it home suggestion. Cheap at twice the price. You'll soon if not already, exceed that price in trips and hotel bills.

 While it is true that you still have to fix the truck, it will be much cheaper and easier to do at home base.

 I was involved (reluctantly) in a similar rescue of a English double deck bus that had been sitting for decades in a field as a stationary display.

 My Boss bought it "sight-unseen" and re sold it to radio station in Huntsville AL. He came to me (mechanic for the company) to ask what his son should take with him for the trip. I argued that it should be towed to our shop, gone through before delivering to the end buyer. 

 I was overruled, and the son set off for Tulsa,Ok. The bus ran after a fashion but the clutch went out after one trip around the block. Son flew home.  I was dispatched to fly into Tulsa and a clutch was air freighted in from England. I was supposed to install the clutch and deliver the bus to Huntsville. Again I argued against it. 

 I got to Tulsa with a bag of tools and a waiting crate that contained a clutch (turned out to be the wrong clutch cover). I had to disassemble the pressure plate and move it to the old cover and re assemble. The Flywheel had a removeable wear surface that the disk rode on. It was cracked in 1/2 from heat. I finely got them to see the folly of trying to take this bus over the hills to Alabama in its present condition. They asked if I thought it would make the trip to Chicago? At least that trip is more or less flat. I wasn't in favor of trying but at least if it made it part way home it would be in the right direction. I spent the better part of a week fixing minor stuff and getting more or less legal to travel with things like wipers, exhaust and lights.

 Several local trips on city streets, it did ok, but 10 miles out at speed, it seized a piston. I let it cool off and nursed it back to the bus co garage that had sold it to my boss. 

 Finely the bus was towed to Chicago, where a new flywheel wear surface, new piston and rings in one hole, and other things were taken care of.

 Long and short it cost way more than 3x what it should have to get the bus in roadable condition to be delivered. 

 I fear you are following in my (reluctant) footsteps, spending more money trying to save money!

 In my case the rings had seized in the grooves, and while ok at low speed/load when the piston expanded under load, that was "all she wrote", and it was all over! Always a risk when buying something that has been sitting for any time. 

 Your money, your choice but at this point that $1500 sounds damn good way out and the cheapest option as well.

Edited October 24 by Geoff Weeks

[alabamaslammer]

just got home without the truck. she drove much better today than yesterday evening or last week, and i was unable to get her to bog and die on moderately flat ground (no big hills/pulls) before parking to work on the brakes. i was able to get the truck - and rear passenger side front axle brake - to smoke heavily. after noticing the brake smoking, i saw the truck was leaking air out of the bottom of a bendix valve body after the parking brake was released. i am not sure how long this was going on for. the engine power was incredible today at one point, and that was with one set of shoes grabbing/smoking. the additives are clearly helping de-gunk the fuel system. the electronic malfunction light did not flip on today or yesterday, so no fault codes on engine. or trans. anyhow i pulled the bendix valve body and it looks like they sell rebuild kits for $30-40 so i will order tonight or tomorrow. i agree the tow quote is attractive. 

[mowerman]

If you’re talking about the foot valve, I had mine part of around 30 years ago and there wasn’t a whole lot in it from what I remember it was just a piston and an O-ring that’s quite a rig you got there. I’m sure once you get everything dialed in that Truck otto serve you well good luck, bud