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Mack AI460 AI427 AMI low torque low horsepower poor fuel mileage granite , dead dog , remediation


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Macktechnician's contributions won't be forgotten.his numerous post with attention to detail will continue helping Mack owners stay on the road for ages to come.Hopefully the right people will come to sense and let him back, if he so wishes of course.

Thank you sir.

Red

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9 hours ago, R.E.D said:

Macktechnician's contributions won't be forgotten.his numerous post with attention to detail will continue helping Mack owners stay on the road for ages to come.Hopefully the right people will come to sense and let him back, if he so wishes of course.

Thank you sir.

Red

What he's been banned from the site,WTF..

11 hours ago, R.E.D said:

Also just got done putting the s400 on the granite along with better flowing manifold.Piping and muffler were changed to 5".Haven't drove it yet since I need to tidy up ,but I can already feel the truck's rpm climb easier..

By the way just would like to mention something if it hasn't been already said.Make sure the manifold is centered between the two cylinder heads ,other wise fuel lines won't fit..DONT ASK ME HOW I KNOW.😁🇺🇲

Great to hear a report back as to how it all worked out when you get a chance 

 

Paul

On 8/23/2020 at 6:35 AM, mrsmackpaul said:

Great to hear a report back as to how it all worked out when you get a chance 

 

Paul

Paul

Ran the truck this morning on the same routes as before and I gotta tell ya it pulls way better than before .Uphill didn't have to down shift as I usually had to do.Also I'm not having to rev the truck past 1800  in order to shift smoothly , so that should improve mpg.next step is injectors and a flash since I'm still at 9b. 

Fantastic stuff, it's always good to get feed back to know if the results on these mods are going good 

Sounds like another winner 

 

Paul 

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  • 3 months later...
  • 1 month later...

Finished today installing manifold, GR 5”, yts 467 and 100hp injectors. It feels stronger sometimes, but the issue of low power for a while, then suddenly motor pitch changes, turbo spools lots higher and pretty good power thereafter is still there. Its random, sometimes great power in first gear, other times it may be weak for a few gears, then decide to make power. It seems to be related to throttle application, ie if its doing its “low power” thing, a rapid release and reapplication of throttle once or twice MAY bring in the power, but sometimes not. We changed the accelerator  early in our ownership of this truck chasing this issue to no avail. Any ideas? I have a boost gauge ordered, maybe once installed it may give me more info to chase this issue with. It appears reading through the forums that a few others have experienced the same issues with similar age trucks, but I haven’t seen any final cures posted.

Finished today installing manifold, GR 5”, yts 467 and 100hp injectors. It feels stronger sometimes, but the issue of low power for a while, then suddenly motor pitch changes, turbo spools lots higher and pretty good power thereafter is still there. Its random, sometimes great power in first gear, other times it may be weak for a few gears, then decide to make power. It seems to be related to throttle application, ie if its doing its “low power” thing, a rapid release and reapplication of throttle once or twice MAY bring in the power, but sometimes not. We changed the accelerator  early in our ownership of this truck chasing this issue to no avail. Any ideas? I have a boost gauge ordered, maybe once installed it may give me more info to chase this issue with. It appears reading through the forums that a few others have experienced the same issues with similar age trucks, but I haven’t seen any final cures posted.

No smoke, and quite, sounds like your barely on the throttle, in fact when she is about to start pulling, you can hear the engine tone get deep and louder before anything else, almost like starving for fuel

Big John!

This may be off the mark Here  but I am going to post it anyway! Early in the evolution of the drive by wire  engines, to skirt regulations, manufacturers Were duel Mapping the softwear,If you were light on the throttle it went down the Bulldog bunny trail loafing along  ,If you were aggressive with the pedal it would take the Bigdog  road map for hills ! Point being !  Im wondering if you have a programing issue or self training issue , And you need to be driving with a more  aggressive foot! 

Just a thought

FJH may be on to something.   Knowing how those granites were before we gave them their testicles back, I was in the habit of pretty much just floorboarding  the fuel pedal in hopes of it going at some point.   Noe they that are remascalutaed, I still have that habit.  So I try to ease into and they seem a lil sleepy.   I think the best method is to get them to you cruising speed and hold a good rpm with them to get your economy.  

Well if you aren't getting smoke when it's sluggish that tells me its a fuel problem 

If it's getting HP sometimes but not others that tells me the injectors and everything else mechanical isnt the problem 

 

I would be suggesting either a crook ground connection or a crook connection on that loom some were 

Thats as far as I can help you as I have never had one of these and am only using what is logical to me

Paul

 

I see what "F" said and I chuckled... I'm guessing this is an E-Tech engine? I used to go in to "Mack Software", and open up the governor seeing and change it from---"Min-Max" to "Allspeed".  dTo try to give it a little more Pep-in-the-step... This doesnt give 50 extra horses... Just better response,   "F" and "V"?? Edit this post if needed...  Jojo

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Good call JoJo, It changes the throttle response. I was reading through this post and it seems that everything was thrown at this lazy dog. One thing I do remember was there was an engine data file available for this condition. We had a roll off come for the same exact problem. We had the Mack DSM involved in this because we were just chasing our tails. Everything seems fine (boost, fuel and the such). It was very lazy getting to speed when loaded especially when the fuel was hot. So we added a heat exchanger to the fuel system on the charge side to help increase fuel density. This helped a bit. There is a "special" Data File that Mack has to correct low power complaints on the AI engines, the problem is that the opacity was very high from the exhaust. We had customers ticketed for this, but the low power problem was corrected. Sorry I cant remember the P variant for the engine datafile. 

I am not sure if the following will help out and I cant remember if this was on the later etechs or the earlier asets. Maybe JoJo or F can help out with this. 

What we found was the air filter restriction gauge was always reading in the red with a new air filter with a quick road test. If you take a look on the under side of the hood. does it have a provision for another opening for an air cleaner? Also does it have a big air cleaner with an aluminium down pipe that removes dirt from the air cleaner? If it does there is a correction for this condition. What we did was we sealed off the existing hole with an aluminium plate and epoxy and riveted it in place. We cut out the provisioned hole and installed a new air cleaner assembly that was used on the CL with a Cummins ISX. This worked out okay because there was less restriction on the air intake. Customers were very happy with it. 

Cant think of anything else.

V

 

I don't know the year of the truck...I looked back but couldn't find it. If it's an ASET/CEGR/ When the little air filter for the VGT controller gets clogged and cuases poor performance, by not working the VGT correctly.. Just another thought, not knowing the engine series. jojo

Thanks for the suggestions, the advice is appreciated! The truck is a 2004 CV with a fixed vane turbo, she is at 12B, the air cleaner shows good on the indicator at maintenance intervals(but it does move when reset indicating it isn’t stuck), ill ask my dealer about changing the governor setting to allspeed, and if he can find the referenced data file for the low power AI complaints. The truck is originally from up north, so corrosion on a connection or ground is a possibility, but we have checked them(the ones I know of) more than once, never found a bad actor.i would think that a bad connection would progress over the years till complete fail, but maybe not. 

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Have you pressure checked the intake?  Someone correct me if I'm wrong, but if you have an intake manifold gasket leak and the engine is not reading enough boost/intake air pressure, then it will not supply enough fuel.

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I keep a C.A.C. pressure test kit on my svc. truck... in 15 minutes I'm testing for leaks.... I have found many loose clamps,, and of course, cooler leaks too...  I never did like the one-piece intake that mack used. always sprung a leak... jojo

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