427 aset ac ..

[Artful dodger]

So I wana start with thanks gotten some incredible help thru this forum I need more . As a few of the fellas on here know I bought  Mack having no idea that they where so diff than the rest of the field.. thought I was getting an e7 per the seller nope 427 asset ac.. hooking it up to computer that’s available it pushing 426 hp it has all new epus new compressor new pulleys new steering box new radiator new fuel lines newer suspension on the truck still Hendrickson air ride tho . I driven owned and repaired trucks most my life so I’m not green there except  for this motor .. it was deleted exhaust to egr plugged coolant still runnin thru egr  cooler I’ve driven a lot 400 hp trucks and this one doesn’t seem to have the power those do..  is it a Mack thing ? rearends and tranny maybe  think it came with rearends and tranny from factory  ??

[Joey Mack]

As one who drove many of these, i find that the power is there, but the EECU wont let it get up and go, like a good old mechanical diesel.. i did manage to somehow do an ASET C inframe a few years ago, and to my surprise the driver said it never had this much power, so it is possible.. wish i could remember my recipe..  i hate both ASET' s.. 

[Artful dodger]

Joe I figured you would find this I’m hunting anybody with a program or that’s ever set one of these up.  
into stupid to quit I guess and I’d like to keep a Mack engine in this. I think a 13 speed is where I’ll have to start maybe being able to split the top will help this just falls on its face between gears

[Joey Mack]

I am very weak when it comes to programming. Been away from the dealership for 6+ years now.. 

[fjh]

2 hours ago, Artful dodger said:

Joe I figured you would find this I’m hunting anybody with a program or that’s ever set one of these up.  
into stupid to quit I guess and I’d like to keep a Mack engine in this. I think a 13 speed is where I’ll have to start maybe being able to split the top will help this just falls on its face between gears

Do you still have the same turbo on there as you had when you first posted? are you still (Checking or  resetting ) the turbo sweep as we discussed? again if the program gets used to a certain sweep on start up it will save it each time it starts! if the vanes get stiff (carboned up) the turbo sweep will change! 

[Artful dodger]

Sorry fjh been putting out other fires yes I have been watching and checking the wastegate position and it’s actually going back to the same place everytime now I’m not sure if having all the cylinders firing correctly may have changed things or the exhaust manifold being fixed idk the answer to that. And I may be reading the truck all wrong. This may very well be all this 427 has my theory was that ten speed transmission suck and the gears seem to be relatively tall in 10 I can run 85 90 mile an hr empty tried it once just to see if it would still only at about 16 on the rpm’s but when u start up a hill and obviously that overdrive gear isn’t gona pull much but I’ll get down to 7 pretty quick my thoughts where the half step drop on the thumb splitter would allow less space keep rpms up and it would continue to pull without dropping to 35 45 miles an hr and I’m not running super heavy 18 ton at most and grade makes a diff to just seems like it should have a bit more I get my ass handed to me by 350 hp trucks. All the time .. also since new epu have been put in there’s an oil leak turbo side left to right it’s seems to be at first 2 epus too of brand new compressor I can’t tell where it’s for sure coming from I’ve washed it real good and tried to see but I just can’t tell 

[Joey Mack]

if you have access to a Mack software program, you can change the governor setting from 'min-max' -to- 'all speed'.  that can pep up how it takes off.  I wish i hadnt lost what I used to know about the programming..  sorry bud..  These Mack engines are slow to go anyway..

[fjh]

So do you have a boost gauge I don’t remember?

[Artful dodger]

No boost gauge fjh sorry for delays in response dads getting worse and more a more time being spent with him . So honestly this damn truck on the low side will pull the house down. It’s up hill that causes it to just fall flat and I’m not talking 7% grades I’m not climbing whistler im talking just run of the mill up downs it just doesn’t like them. I really like this ole truck and just want it to do what I think it’s capable of doin and I’ve got a lot of blood sweat money and tears in it!! If I could find someone to tell me how it’s programmed I think that would be a start I’ve asked around nobody seems to know and the dealership hasn’t been much help since it’s deleted 

[Mackpro]

Like FJH mentioned, you need a boost pressure gauge. Just get a small liquid filled air pressure gauge better if it’s a 0-50 psi but a 0-100 psi will work, hook it to the intake manifold, there is a 1/8” pipe plug just for this . Using 1/4” air line run it in the cab and see what boost pressure your getting under a load,  33 psi is what I always shoot for on the ASET AC engines. 

[Mackpro]

The HP and torque curves are so narrow with the AC and even worse with the AI engine. With a AC 427 engine traveling on flat ground at 65 mph your RPM’s should be 1600. Someone might have swapped out rear axles ( ratios) or transmission and gotten the torque and HP curves out of wack. This was a common issue on the AI engine in the dump trucks we saw. The AC engine was more forgiving 

 

[fjh]

42 minutes ago, Mackpro said:

The HP and torque curves are so narrow with the AC and even worse with the AI engine. With a AC 427 engine traveling on flat ground at 65 mph your RPM’s should be 1600. Someone might have swapped out rear axles ( ratios) or transmission and gotten the torque and HP curves out of wack. This was a common issue on the AI engine in the dump trucks we saw. The AC engine was more forgiving 

 

He has been fighting with this truck for awhile now ! From what I understand the EGR is capped off! From my experience should throw a code for egr flow but not effect or derate the engine How ever this may have changed in certain years?! At one point it was pulling well ??? not sure if this has changed! He claims the turbo is stroking completely on startup! with out the boost gauge it is hard to gauge whether its getting all it has! Also its hard to know if the turbo blow off or by pass is stuck open or getting weak! I understood that that valve started bypassing at 20 or so psi! 

[Mackpro]

On 9/6/2024 at 9:14 AM, fjh said:

He has been fighting with this truck for awhile now ! From what I understand the EGR is capped off! From my experience should throw a code for egr flow but not effect or derate the engine How ever this may have changed in certain years?! At one point it was pulling well ??? not sure if this has changed! He claims the turbo is stroking completely on startup! with out the boost gauge it is hard to gauge whether its getting all it has! Also its hard to know if the turbo blow off or by pass is stuck open or getting weak! I understood that that valve started bypassing at 20 or so psi! 

I gotcha. Yea the boost pressure relief valve is a place to start. 

[Mackpro]

Going through my notes, not long ago I  had a 460 CHN with low power complaint. New injectors, good fuel pressure, turbo actuator adjusted to 37 psi of boost , newest software. All perfect and ran great with no trailer. We wanted to replace the fan clutch because it was stuck on but owner declined . Finally he gave us the OK and once we replaced it and fixed the low power power problem. That fan sucks 30 to 50 HP on some engines. 

[fjh]

29 minutes ago, Mackpro said:

Going through my notes, not long ago I  had a 460 CHN with low power complaint. New injectors, good fuel pressure, turbo actuator adjusted to 37 psi of boost , newest software. All perfect and ran great with no trailer. We wanted to replace the fan clutch because it was stuck on but owner declined . Finally he gave us the OK and once we replaced it and fixed the low power power problem. That fan sucks 30 to 50 HP on some engines. 

Yup I'm getting a bit rusty with this stuff been away from it for a bit now ! So I'm glad you chimed in! I'm relying on memory and that's not as good as it used to be!🙄

[Artful dodger]

Good morning fellas well I haven’t been to bed yet but heard phone going off so thought I’d see . I do believe turbo is stroking correctly and maybe fellas I’m just expecting more out of this thing than it’s got picking up a boost pressure gauge today after a nap and gona see what that tells us.  65 miles per hr 14 on rpm . Just put new radiator on it EGR is capped off 6 new epu new ex manifold new compressor oil pressure at idle around 30 down the rd 60  engine temp rarely hits 200 even on hot days generally stays in the edge of blue into green a bit.   I’m leaking oil after the epus where put in can’t figure out where it’s coming from exactly pressure washing it this afternoon and hopefully figure it out. My opinion this is a pretty cool ole truck I’m gona try to save it I wish I knew or could find out without having to pay Mack dealer I’m sure 1000s to tell me how it’s programmed oh and yes throws egr fault code all the time think I answered what can think of 

I sure appreciate everybody 

[Mackpro]

The oil leaks are probably the bottom exhaust manifold studs. They are drilled into the oil return/push tube area and you have to put RVT silicone on the studs if oil is seeping around then . This is only on the bottom studs. Using to long of bolts or the incorrect studs can actually hit the push tubes and cause issues 

[Artful dodger]

I asked shop that ? After the oil leak started and was told that the studs went no where near an oil or water tube but in shops defense first time they had ever heard of this engine let alone worked on one I was afraid to do the manifold and  the studs at home because I always snap one off  and spend half a day getting it out .  Also the air valve that’s bolted to the firewall up high on drivers side like right by the vgt valve is there a specific name for it  it’s leaking out the diagram on the face of it

 

[Joey Mack]

Is that valve silver with a red button on it, and is 'teed' into the treadle valve?

[Artful dodger]

Yes it’s seeping and the what I believe to be the brake valve is leaking out the diaphragm or rubber cover on the front of the valve.  In my infinite wisdom thought I had that fixed I had a brake can on the front pusher blowing air out the top first I just cut the brake line (it was old) pinched it off thought that  would do it well it did not. In my experience which compared to yall isn’t much especially with Mack if valve is leaking most of the time it’s something down the line that’s bad not the valve but I’ve yet to find it.  Guys I just wana tell you how much u all are appreciated fjh joeymack the hienz Mackpro you guys have hung in there with me.. life throws all kinds of curveballs and it’s thrown me a good one but I still believe that there are good people out there that are willing to help you without any desire for anything in return.. sometimes a guy doesn’t need a hand out just somebody to help him up  hats off to you fellas thanks 

[Artful dodger]

Worked last night or tried  out of the blue I get a bad vibration at 45. 50 mile an hour again first time this happens carrier bearing cradle was loose 2 bolts that hold it to the frame.. I carry an entire tool box full another box with nuts and bolts a 6 ft cheater bar 12 ton bottle jack 3/4 inch drive ratchet 16 inch ext and correct sockets and a few air tools in this truck everyday.  Anyway u joints bout to come apart I limped it home about 3 this morning that’s what we are doin today any neat tricks to make changing these suck less? lol

[Joey Mack]

There is a tool that uses small cables and a jack screw...  Kinda pricy.. 

[Artful dodger]

I went to harbor freight got a heavy duty Ujoint puller  is what they call it did the trick got them replaced used strap and come along to hold up drive shaft up easy peezy still don’t know about the valve tho still pissin air

[Joey Mack]

is the valve leaking only when the brakes are released? is the brake valve leak really the valve, or is it the plastic air manifold in the firewall that has aboout 8 lines connected to it?

[Artful dodger]

 

This is what I hear and see what u think

 

 

[Artful dodger]

Brakes are set it’s leaking it’s actually gotten worse