Mackpro

I would go with a aftermarket boost pressure guage (the boost and manifold pressure guage means the same thing, some people call it one or the other). If your truck has one it will be in the upper left hand corner of your dash. To install a factory boost guage the dealer has to reflash the ECM to read the new sensor and transmit it to the new guage. The aftermarket guage just hooks a piece of 1/4" or 1/8" plastic air line to the intake manifold and goes straight to the guage in the dash. http://www.pdqperformance.com/product-p/114524.htm

Best I remember this was an unoffical fix that problem and no service bulletin existed. I remember talking to our DSM (distric service manager) and told us to how to install the resistor. The 680 ohm was installed inline on one of the two wires at the intake manifold temp sensor. I will try to find out more.

Thanks for the info, I'll see if our parts guys can keep a kit or two.

The engine is a ASET AI. The 370HP was not made for to many years due to the EPA finding out how dirty it was. The 370 was dropped but they kept the 300, 350, 400, 427 and 460HP till they went to the MP series engine. Alot of state road dept dump truck had this engine. Best I remember the performance was equal to the 427 HP on paper (torque output). Most everyone around here didnt complaine about low power. Main thing to watch on these engines is the belt tensioners/belts, air filters plugged easy in dusty conditions, if it has a Powerleash engine brake have the valves adjusted and make sure they replace the rocker arm hold down bolts with the new upgraded ones. The Horton fan hubs also have bearings that go out and most Horton fan drives have the built in fan clutch that seems to go out/slip early. Always use Mack filters and dont forget to change the spinner oil filter. While at the Dealer get them to reflash and reprogram both ECM's up to the "Step 12B" with throttle calibration (makes them run better) The torque curve of the AI engines can sometimes be small so if the pulls good dont go changing tire size. I'm not much on pryometers/EGT guages but I think a boost pressure/manifold pressure guage is a must.

Hooked up that fridge you were wanting to make sure it worked and it did make ice!

The bottom exhaust manifold bolt holes in the heads are drilled all the way into the push tube opening. Oil runs down the push tube to the lifter, the oil stays there and can come out past the lower exhaust manifold stud. We remove the bottom studs and put silicone/RVT on the threads (threads of the stud only)on the stud and reinstall. It's a common problem . All ETECH style engines are like this.

Just replaced a FIC module on a truck just like yours. This one quit running and never would start back. The FIC would not supply 12v to the injection pump. We have several test ECM's here to use so it kinda makes it easier to locate the problem. Glad you have about got it figured out!

I know we put alot of fuel supply pumps on. You can remove yours and see if the gear is slipping on the shaft. Also check your oil level for being over full. Sometimes these bad supply pump can leak fuel into oil. Does yours have spin on fuel filters or the Davco filter in the clear housing? If so it has its own check valve.

If I was at work I could get you the Service bulletin #'s but I wont be back till Tuesday. Also has the engine ever had the injectors replaced? Some over fueling injectors could be the cause although probably not. Too much fuel or not enough air (boost) usually causes high exhaust temp. If you have any type of fuel heater make sure it is shutoff. Make sure the hole on the inside of the hood is lined up with the air cleaner housing hole and the rubber boot is sealing off the hot air off the engine.

Some techs just seal off both sides of the aftercooler and pressurize it by itself. I leave the aftercooler hose going to the intake manifold on that way you can check the intake manifold and the air compressor intake piping. Of course some of the intake and exhaust valves in the heads will be open and air will go past but with enough air pressure and a squrit bottle of soapy water you can find all kinds of leaks.

Your 2003 460HP is a CCRS ETECH engine which is a refined ETECH engine. The 460's have the wastegate turbo ( not to be confused with the ASET VGT turbo) , if you try to adjust the linkage and if the boost goes to high it will derate, we already tried this. Mack has some good Service bulletins on the CCRS wastgated turbo. We put alot of diaphragm kit on thoses turbos, its a bitch to get them set right and open when they are supposed to. Another place to look is the intake manifold gaskets, they usually blow out around #1 cylinder, Mack came out with some steer core gaskets to solve that problem.

One of my friends owns a early CV with a regular ETECH 400HP. His friend bought a CV as well with a 427HP. Now my buddy wants his 400 bumped up but like you he doesnt want to pull the cam and go through all that cost. So I called http://www.rochesterfuel.com/products/performance-mack-c-23_67.html and talked to them, they were very helpful and the guy I talked to really knew his stuff. (their injectors are alot cheaper than the Mack remans)I had my buddy give them a call but he hasn't decided what to do yet. Maybe a set of stage II injectors might be all you need. I also posted this, however it only applies to 427 CCRS engines, just in case anyone out there has a weak 427 CCRS. Here's a little tip for 427 CCRS engines with low power. We bought a fleet of 2002 CH's with this engine and all were low on boost pressure and power. We changed turbo and injectors, adjusted valves and did everything we could think of and still low turbo boost/ power. I called my buddy at our other Mack location and he said to replaced the injectors with 460P (736GB420M3X) ones and call Mack and have them turn on engine datafile 1MS5135. We did this and WOW what a difference, went from 22psi boost to 30 psi and this was after we put the old turbo back on. Just something I thought I would pass on to you guys. One of our customers bought one of these trucks and fixed it himself (I first put a 460HP datafile in it )but he had some bigger injectors buit and put on a 500HP Detroit Diesel 60 series turbo on and says it will scream, I have seen it in action and it seems to really get up and go.

Yes , there is a data file for the engine ECM that Mack turns on and the dealer programs it into the truck. Since your truck is a regular ETECH 355-380. I have some info for ya here in a bit.

Injector # 736GB415M2X (X means reman). Turbo # 631GC5173AMX (of course X means reman as well). The orignal 460 HP turbos were around $800-900 but the newer models have a super hard titanium impeller wheel. Most turbo shops can build the same thing with out the titanium wheel for a whole lot less. The camshaft has to come out and the cam gear pressed off and a off set keyway installed to retard the timing to prevent overheating in the summer. If you had a CL with the huge radiator you might get buy without the keyway change. We tried it with a RD and a CX and was ok in the winter but when the summer came they overheated.

Guess ya'll have had all girls?

Will do. And as far as kids go , sometimes I feel like I have "2 too many". The 12 hours in the Tahoe with 2 little ones coming back from Florida will make you wanna get your nuts cut. I'm 42 and we (wife is alot younger than me) might have one more if I was sure it was a girl. No more mean ass boys!

The injectors are $181 each and the Mack turbo is around $2100. I think a turbo shop could build one cheaper though. The labor to change the cam keyway is what is the killer. About 16+ hrs to change the keyway. If we were to do the whole conversion in our shop it would be over $5000.

A regular ETECH has a plastic fuel return hose coming off the front or back (mostly front) of the head going to the fuel pressure regulator on the passenger side of the block above the air compressor. The CCRS has no plastic line. The ASET AC and AI engines also dont have the line.

Yours was built on 1/16/2001 and is a regular ETECH engine , same as engine above, requring turbo, injectors and off set cam keyway. My hope was yours being built in 2001 was a CCRS style engine that requires no cam keyway change regardless of HP level. If it was a CCRS ETECH it would be cheaper to bump up due to no keyway change. As with all HP upgrades on ETECHs make sure you have the big vibration damper on, if not get one. You can tell if you got the big one by it almost touches the front motor mount horseshoe. On the small damper you can fit your fingers between the damper and mount.

Good to hear they could get it to act up. Keep us posted on how it turns out.

I was first thinking maybe low fuel pressure but probably not. I would go ahead and get the lastest software and data files for both ECM's (step 12B) and make sure your turbo has a *****5176***** in the part#. If it has a ****5171**** series turbo(2004 year model mostly) dont change the software. When we changed turbos from a 5171 to a 5176 the dealer has to change the engine software and data files. Most of the 5171 turbo are all gone/blew up. We have run across some customers who changed their own turbo to the new style and didn't get the software changed or the VGT calibrated and this caused all kinds of weird problems. With that said I would get the software/datafiles up to date, have the fuel pressure checked (80 psi)(if the supply pump has never been changed it might need it), have them check the boost pressure relief valve on top of the intake manifold (spring wears through the end of the housing), have them check for fault codes for the VGT/turbo and calibrate the VGT (must have 150 degree water temp) lastly have them unplug the connectors for the engine ECM and check for antifreeze in the harness plug. Thats all I can think of for now.

Oil is better than finding antifreeze in harness/ECM connection. We usually find antifreeze at the engine ECU and it can eat the terminal/pins out. Clean out the connections with electronic contact cleaner and recheck and clean every week for a month till it no longer showes up at the connection. Glad you found it.

I'll try to post a pic of the ECM wiring in the morning, We have a new PC hooked to our scanner, hope I can get it to work.