OldRedMack

Just ordered the engine harness from nextran in Atlanta.  $933.00

M&d was good to deal with, but call them with your injector numbers.  The website numbers don't always match up with what you need.  You can buy as many or as few as you want.  They are really only at there best efficiency for around 5k hours before you start losing some power and fuel efficiency.   I don't replace the valve cover gasket unless it's ripped or torn.  If it looks good just make sure it and the head surface is clean and smooth and you shouldn't have any problems with leaks. 

It might be a good time to go ahead and put a set of injectors in it.  In the grand scheme of things they are pretty inexpensive, about $100-$125 a piece depending on where you get them.  In my experiences if the manifold stud is leaking they usually come out pretty easy cause they are sitting in an oil bath.  Put a ratchet and socket on it and see if it turns.

I'm also a fan of the high range low hole on the 8ll when using at a yield or making a turn.  A lot of options and ways to shift really a great transmission in a dump truck.

On 1/28/2022 at 9:29 PM, JoeH said:

Curious, how much did the harness set you back? We just bought a 2003 AI350. Harness seems ok... For now....

I'd love to know as well,  I've had the same issue since we bought this truck. 

2001 had the cam issues, ours has a cam job done every 3-4 years.  Our 2, 94 rd with mechanical engines have well over a million miles and God only knows how many hours and we have never been into the engines.  Still work every day going on 30 years as dump trucks.

Pressure check the intake, might have a blown intake manifold gasket.

Check your retaining nut on the drive shaft

You are only going to get 5k good hours out of a set of injectors.  At 5500 hours I was down 3-4psi of boost, and now at 6400 I'm down 8-10psi.  Got a new set ordered and waiting for delivery.  If you search for those threads we have really good vendors to buy from listed as well.

The short of it,  have it re-programmed to the 370hp setting it has more torque. Get an e7 exhaust manifold, a s400 turbo, and then the 427/460 injectors it will wake right up.  I have a thread on the 370 and mack tech has 1 on the 460, same principles as both. I'm to computer illiterate to know how to link them. 

Do you have a power wire going to a trailer connection that has a bare spot and is shorting out and tripping the breaker on the firewall when you hit a bump. Had that happen to me before. 

Good chance you have a weak eup, that happened with me and new injectors. 1 eup wasn't strong enough for the new injectors, replaced it and all was good.

I chucked mine in the scrap bin. Use the old style and get an s400 turbo.

32 minutes ago, Mackvette1 said:

Just did the intercooler.  I can do that tonight, that should also tell me if my pipe for air intake on air compressor is good or not also ...how much pressure? 30lbs like the book says for the intercooler test? 

Only took about 2psi to find my blown gasket on the manifold, It doesn't take much.  The key for me atleast is that it is quiet while you are doing it so you can hear the leaks. 

2 hours ago, Mackvette1 said:

Pressure check intercooler and found no leaks and it passed the leak down specs...so onto the air compressor intake pipe...plan to just use 3/4 inch hose to test it for a day and see what happens 

Did you pressure test just the intercooler? Or the whole intake? Need to pressure check the whole system.  I take the air inlet pipe off of the turbo and pressurize the whole system, just bump the engine over till the valves close and it won't take much psi to find a leak.

Check your fuel filter stand for cracks, took us 2 years to find that problem on a truck. 

If alignment and tires don't cure, might be a bad wheel that is out of round or you might need new spring packs.  I've never really noticed any difference with new shocks compared to worn shocks. Also check the motor mounts, they normally make more of a banging sound when they are worn, but if they are shot possibility that it could perpetuate the bouncing. That was a lot of words to say in my experience a speed related bounce has almost always been tire and wheel related.

GA is 64,000 lb gross on 3 axles, lift axles only mean you can haul less weight in GA. Also even though it's 64k gross, if you have a lift axle on the truck you have to use it. So you get less payload with more wear and tare.

If it took 2 hours of sitting turned off to drop that much then it's not a huge leak and the truck is safe to run.  But if it was running and did that then you would have a problem. 

Looks good to me, your just caught between gears at that range.  Crusing rpm with my truck is 1650-1750 at about 600.

Good enough answer to order 1.  I know it should be as simple as calling mack and giving them my Vin, but I really don't like dealing with mack in Atlanta. Google gave me the part number for a 460 and I gave it to my pai guy, so we will see when it gets here.  Getting a new pressure relief valve also.  The truck isn't running bad just seems a little lazy, boost is off about 2psi.  But the Pyro hasn't changed so I don't feel like I have any intake leaks.

It includes the filter pad, just not sure if they are the same thru all the power ranges or different depending on HP.

Does anyone have the part number for AI fuel pump.  I have the 370, is the 460 pump different?