Mackpro

My buddies 2012 CHU daycab with no fairings, 505 HP, Mack 10 speed trans, rear gears are in the 3.40 range ( cant remember) just pulled a loaded van back and forth to StLouis at 68 MPH and he got 6.8 MPG. Boss man said he heard of MP-8's with super high rear gears running 13 speed trans and mostly running in 12 th gear but on flat ground going to 13th gear and the engine RPM dropping to 1100 RPM and getting some unheard of MPG. Not saying its true but thats what I heard.

The last RD688S I can find was built on 4/7/03 and labled a 2004 model. It did have a AI-350 ASET engine in it. However some of the other guys may have a better way of looking it up in the Mack mainframe.

I have seen alot that average 6.9MPG with and without wind farings. Keeping the MPH down is the key. None were equipped with a 13 speed though , Here we rarely see a 13 , 15 or 18 speed trans anymore unless in a GU.

Looks like on 4/12/11 a Mack dealer set up the step 12B downloads and new datafiles for the engine. Its shows the dealer downloaded the new files in their laptop but the dealer didnt send back the confimation file saying they were installed into the truck. Not saying the dealer didnt install them but who knows. It shows u have a fuller 8LL trans and 4.42 rear gears. Truck came with 22.5 wheels but no tire size listed. If your running full size 24.5 tires they might be to tall for your 350 HP. We sold 2 CV's with 400AI's, 8LL trans, 24.5 tall rubber and 4.17 gears. Almost had to buy them back from some very unhappy customers. The AI engine has a very tight window for every thing to work right. Any one thing out of wack/changed and its low power complants. The good thing bout the AI engine is to do HP upgrades you just need to change turbo and injectors and download. Older ETECHs you sometimes have to change the camshaft keyway. In your case you might need to upgrade to a air fanclutch as well.

S Here in the States the CCRS 460 has a wategated turbo and if you try to change anything or adjust the wastegate for more boost it will derate the engine when it overboost's past specs. The 427 HP CCRS's dont have this feature or the high$$$$ wastegated turbo. When customers come in for factory HP upgrades on a CCRS we usually steer them towards the 427 for this reason. We have actually turned a 460 down to a 427 due to the customer always swapping custom turbos and injectors.I saw a Detroit 60 series wategated turbo bolted on the exhaust manifold one day on that truck.

We only use Panasonic tougbooks in our shop. They are worth the money if they are used every day by different techs, They get rained on, dropped on the floor, oil spilled on them and thats on a good day. We have the Cummins Insight program which is awesome and of course the Mack/volvo VCADS/ PTT ( which everyone here hates with a passion) and we still use the old Mack software alot. For other trucks we use the Eaton MD-300 which works well on other makes and models of truck and engines and ABS.

If the FMI is 4 that means voltage low or open circuit. If your engine ECM is mounted up on its edge on the driver side of the engine, pull the top/J1 connector loose and check for antifreeze or oil in the connection. Wire number for the # 4 eup are EJ1-24-2.0 and EJ1-41A-2.0 . Which would be pins 24 and 41 in the engine top/J1 connector.

I really cant even remember much about that and the more I think , this actually might have be the VMAC2 E-7 engines ( before ETECH). Too many years, ex-wives and beers ago!

For a 1995 427HP VMAC2 the book says 24-32 psi is where it should be.

I think you have a MID-128 SID-4 FMI-4 code which is the #4 EUP injector pump. But not 100% sure if this is the code you are reading. How are you reading this code?

White smoke is normal on start up on the VMAC 1's and 2's as the timing advance is powered by oil pressure and of course when you first start engine it takes alittle while to get the timing advance moving. On the black smoke, everything on the turbo boost side. After cooler, intake manifold gaskets, dirty air filter. Black smoke is unburnt fuel, Either from to much fuel or lack of air/boost.

His truck is a ETECH style engine with no real injection pump but I know the copper washers you talk of on the older injection pumps, they now have a steel washer to take its place.

The check valve could be bad, its on the pass side of the block above the air compressor. The idle issues is probably that the driver hit the cruise buttons just right and lowered the idle speed, it happens alot, I always turn this feature off in the parameters to keep this from happening.

I would start with a fuel supply pump, unless it has been changed lately. I know we put alot on. We had a 06 CV in here yesterday that would barely run and that fixed it. Once it is running, does it have as much power as it did before?

I vote turn signal switch as well. I hope your style is not the kind that you have to remove the steering wheel to change the turn signal switch. I really liked the days of the old flat dash CH's where you could change the TS switch in under a minute with the right size torx screwdriver.

Not a single warranty claim in it's life which could be good or bad. Seems like a good all Mack truck with T-2180B trans and Mack rears with 3.86 gears and air ride, It came with a 64" mid-rise sleeper. Engine has Jacobs engine brake. If the cam had been replaced and the Jake pins replaced I would not be scared to jump in it and go cross country.

Early ETECH's did have camshaft issuses, intake manifold gaskets blowing out (around #1 cylinder) and Jake Brake (floating pin) issuses. All these problems can be fixed with available updated parts. A great engine!

We had one new 2011/2012 MRU in our area but customer sold it to someone in New York after 3 months of use. So glad to see it go!

We lost alot of customers in 2004 when they bought CX's and CH's with the AC engines. Had to change the fan belts at every oil change (due to under hood heat damage), EGR cooler failures, turbos every 80-100K miles, fan hub failures. It was bad. Afew of the customers traded them in for CV's with the AI engine set up as daycab road tractors, alot less issuses but poor MPG. The CHN's and CXN's with AC engines came out ayear later much improved and things got better as turbos, fan hubs, belts and tensioners were improved/updated. But that bad 2004 year cost us dearly here!

Muffler baffel broken and sometimes gets blown up sideways blocking hole. I doubt thats it but I have seen happen, took me 2 days to figure it out!

Probably just air in the system. Your truck should have the Sheppard 92 series gear box on it. Heres a link to the 92 series service manual. http://www.rhsheppard.com/manuals.htm

You are lucky it has worked as long as it has. I have only seen one around here that still works. Most are black screens. Even the larger VIP screens in the first Visions/CX's seem to fail or go bad quite often.

We have had two home invasions within 25 miles of my house where the victims open fired on the bad guys. We actually have a low crime rate around here with only maybe 1 murder a year. I have had my CCW permit for almost 15 years, I never leave home with out it!

Pull down the metal kick panel in front of the passenger seat below the fuse panel. Behind this panel you will find the ABS ECM and the VECU ECM. The ABS ECM will say WABCO or Bendix or some other ABS system maker . What you want to look for is the Mack VECU ECM. Its a thin black plastic rectangular ECM . It has 3 push in wire connectors but places for four. First thing to check is see if the VECU ECM is faceing up where the connectors come in from the top. If so thats a bad sign, water seems to so how get into the ECM when facing up. Regardless unplug all 3 connectors and check for green or damaged pins. If all OK and the ECM is faceing up , unbolt it and turn it faceing down and reconnect all plugins. Next is to try to catch it "not starting" and check to make sure all 4 power relays (next to fuse panel) are powering up. I think #3 power relay fires up the engine ECM. If this relay fails all will seem to work but crank no start and this failure will not set a code.

The screens were only in the late 2003 ASET style engines. Your safe as you have one of the best engines mack ever had.