JoeH

You have oil pressure, but your engine shut down light is staying on. How's your coolant level? Also these may use 2 oil pressure sensors. One for the gauge, one for the EECU.  Will it continue to run if you hold down the shut down override switch?

Can you clarify which fuel system you have? Does this have 6 individual EUP's or one "traditional" style inline injection pump? If you aren't sure then post a picture of the passenger side of the engine, we can tell from that.

If it has a "traditional" injection pump then disconnect your shutdown lever on the pump from whatever electric solenoid controls it, put it in the "run" position and see if it'll run.

There's so many variables on truck specs that I think this is a hard question to answer. A highway truck isn't going to survive as well as a heavy spec truck.

I think this depends on what kind of accident you're planning on getting into. Looking at my trucks, I'd say my DM686SX has the best crash rating.  Frame is made of two 3/8th rails, and the front bumper is massively strong, sticks out a couple feet in front of the radiator. This truck is my Zombie Apocalypse go-to. Currently set up with a 5th wheel for yard work, I'd haul a 7,000gallon 2 compartment tanker trailer, one compartment for passengers and the other for either potable water or diesel fuel.  This truck would plow through any road barriers with the bumper it has.

I don't think you'll have any thermal expansion issues by adding ribs underneath your hood.  If I get a minute I'll take a picture of the inside of my sailboat.  It has cedar ribs that are fiberglassed to the floor to help give it strength.  It basically creates a fiberglass box channel that gives structure to the otherwise flat panel.

You could fiberglass in plastic pipe or even foam insulation for water pipes. Metal is going to add a decent amount of weight to the hood, which will make it harder to open, but you don't need anything heavy, just something to hold the shape for the fiberglass resin to set.

You can add strength on the underside of the hood by fiberglassing ribs into it that bridge across the cracks. Metal rods, scraps of wood... Whatever does the right job.

You say you bought an R model? Your VIN on the frame says otherwise. Terry is spot on. Last 5 digits means it's the 31744th truck built on that VIN sequence.  Not sure if the cab tag is a serial number or just a cab model part number.  My trucks all have the same tag.

What causes the steering wheels to crack? Is it UV?

I.dpnt think so, but just make sure any thermostat you put in has about a 1/8th inch bleeder hole in it to allow it to burp on initial warmup.

On 1/25/2024 at 3:41 PM, DirtWorx said:

1999 Mack RD688S E7 misfire under load, cuts out sporadically - injectors, EUP, ECM, or wiring harness?

1. Engine runs correct under normal operating conditions unloaded.
2. Engine cuts out sporadically for a split second then comes right back on when loaded or unloaded.
3. Engine sputters under uphill load until throttle is decreased.
4. Engine injector(s) disengages and reengages sporadically under uphill load.
5. Diagnostics shows injector 2 and 3 low voltage.

Find a solution yet?

EA7 is an Australian E7/ETECH i think. On the engine I'd expect the harnesses to be effectively the same.

Id be fixing that motor asap, that's a nice R model. Great history, sorry to hear about your dad's passing, but glad you've got his friend around in your life.

This project chose me, I didn't choose it! Big difference lol! I didn't want my truck put into a ditch!

Your point #2, is the engine shutting off momentarily? This will likely be a loose fuse for the EECU, I'm guessing this fuse is in the fuse box under the hood. With engine running, wiggle the EECU fuse. It'll probably stall out. It should trip a blink code 9-2 I believe. If your fuses aren't labelled in the box lid then just wiggle the fuses one by one. You'll need to pinch the fuse slot connections a bit tighter, and maybe bend the fuse legs a bit to create more connection. That's what I had to do on my MR688.

Sounds like an issue with your #2 and #3 EUP's, anyone able to elaborate on what to inspect? I'd start with inspecting the wiring harness for any rub through, and make sure those 2 injector screws are tight.

46 minutes ago, mrsmackpaul said:

A bit of fair sized task your under taking 

I did something similar on a farm ute years ago

I was stunned when I put it all back together that everything worked first go

 

 

Paul 

 

I'm about $200 into a label maker, between buying it and buying 4-5 roles of the vinyl cartridges that go in it. Pricey, but the utility value is massive.

This harness will go into storage incase we ever need to utilize it and the engine. I'm sure hoping everything works once I get it all together. 

Still need to strip this cab down further, patch a hole in the floor, replace some seized rivnuts, pull windshields, sand down and paint the cab, and a myriad of other tasks. Probably needs a heater core.

The rear window in this cab was a slider, but I'm opting to put the solid rear window from our busted cab into it instead, since the VECU is located just inside the rear window.  Not taking any chances on rainwater finding it's way to the VECU.

He's a narcissist. He loves the center of attention. Some people villainizing him galvanizes others to love him even more.

My brothers and I all learned to drive on my dad's 1979 R686ST. Video e it for 6 years while we built a volumetric mixer for a 95 RD688S triaxle we bought. Now I've been driving that for 9 years, and we're phasing the '79 into backup/retirement.

I like R's. 🤓 Though I do like that Pete, that's the body style I'd chase if I bought a Pete. Though the hood fenders don't have good off-road clearance. Mack's were built for on and off road. Sat up higher.

A nice coat of paint and that'll be a sharp looking Pete. What else does it need other than tires?  Does it have braided airlines or synflex?

Even just a picture of the R by itself is ok ... 🤠

"Deleted" you'll be on your own to fix, dealer probably won't want anything to do with it, so be prepared to work on it yourself.

Generally Mack's and "deleted" is nothing but problems, but I have no experience in the matter. Just what I've heard. Personally I cringe at the thought of buying an MP engine, but the reality is it's gonna have to happen someday. Injector cups are a regular maintenance item or so I figure from a lot of talk about them in the past. Timing gears are all on the backside of the engine I think, which sounds weird to me. Not sure how others feel about that.

What year? The ETECH and AI/AC engines have a fuel gallery drilled through the block, and there's a plug at the front end of that gallery that's inside the timing cover. This plug can come loose and let fuel into the oil pan. But you need to give us more specifics on engine year so we can know more about what you're working on.

43 minutes ago, Macktruckman said:

Ill post up a picture of it if its ok to post a pete on this thread ?  I don’t know the rules very well. 
Josh

As long as there happens to be an R model posted with it I think a blind eye will be turned to the Pete...