I've read the threads and all I can find is Pilot turns off at 2500 -2600 rpm's...Mine on the other hand is quite annoying and is closer to 2100-2200 going up a slight grade on the interstate. I disconnected my Juice today to run stock for a little while because my Attitude is giving me cranking fits.


I've posted on this a few times but here goes again. When my pilot turns off on (75-80 depending on the grade) it's loud and it's like the truck wants to runaway with power??? When I let off its harsh. Can I get the pilot injection flashed to go off at a higher rpm?? The reason I'm posting now is cause I'm back to the stock program (no juice) and it seems like the lower power levels bring the pilot shut off much sooner (load & rpm). Somethings got to be wrong with the truck cause I can't see GM signing off on a truck that surges on and off at 75-80 mph...or could they?

75-80 depending on the grade? 2100-2200 RPM?


Sounds to me like there could be a couple of things. One, it could be downshifting out of OD. The other is that you might be hearing the fan clutch engage which makes quite a bit more noise. Or you might even have occasion to experience both.


Is it kind of a "roaring" sound? That would be the fan clutch.


Similar but not quite as loud, would be a downshift and the pilot injection turns off, creating more noise.


Do you get an RPM increase when you hear it?

Thanks for the reply but.. I'm familiar w/ the fan as I pull a boat and sometimes see the temps go up and have the fan kick on...sounds like a jet. As far as downshifting, the rpms are not going up other than the increase in speed. With your comment about the fan it got me thinking??? Could the fan be faulty and be on all the time and free up at higher rpms? That could explain why my MPG's don't look as good as others on this forum? But on the other hand I have noticed the fan engage during hot temps. I dunno???

Well the fan being on all the time is not likely, but there's an easy way to check for it being shot. Go out and grab the blades on each side and try to wiggle it back and forth.


If it wobbles, it's shot. That's not likely with so new a truck, but it's possible. It doesn't explain your noise if you recognize fan noise and it's something different.


Could be a PCM problem, but I've never seen anyone post with a similar problem that wasn't explained by the above two options. Nor have I seen anyone post about a confirmed pilot injection early cut off problem.


You might see if one of the mods will move this to the tech section and get one of the genuine Dmax mechs on your question...http://www.dieselplace.com/forum/smileys/Ermm.gif

Well the fan being on all the time is not likely, but there's an easy way to check for it being shot. Go out and grab the blades on each side and try to wiggle it back and forth.....





Make sure the truck isn't running when you do this. http://www.dieselplace.com/forum/smileys/HiHi.gif

Well the fan being on all the time is not likely, but there's an easy way to check for it being shot. Go out and grab the blades on each side and try to wiggle it back and forth.....





Make sure the truck isn't running when you do this. http://www.dieselplace.com/forum/smileys/HiHi.gif





YUK, YUK, YUK....http://www.dieselplace.com/forum/smileys/HiHi.gif


I can see that "Kenny" is alive again, and well...http://www.dieselplace.com/forum/smileys/Hug.gif

SmokeyMax-


The pilot injection on my DMAX seems to shut off right around 2200rpms or so with the juice on. It is much more "rattley" on the highway with the juice on. I believe I read, either on this site or the page, that Edge has to shut the pilot injection off sooner due to the fact they command more fuel. The engine is not as quiet with the juice on either. I guess all trade offs that you need to decide if it is worth it. Also, with light throttle at high speeds, it really sounds like a rattle trap when you get in it and then back out of it. Mine has done this since installed as well. From the response I have gathered this is normal operation with the juice box, it is just that some don't notice or don't hear it.


With the juice box off, it is much quieter, throughout the whole rpm range. It is amazing how much quieter my truck idles without the juice box on....but I have got so used to the extra power, stock just feels like a dog, especially towing...


Bob

I asked my service manager about this. He told me that the fuel quality will also have a affect on the noise. I would have to agree with this because there are days that is much more noticable than others. http://www.dieselplace.com/forum/smileys/Confused.gif


I also like having my music on while driving.....hell then I never hear it.http://www.dieselplace.com/forum/smileys/HiHi.gif


I feel your pain. http://www.dieselplace.com/forum/smileys/Hug.gif I hate the noise also, sounds like the damn thing is coming appart.

SmokeyMax-


The pilot injection on my DMAX seems to shut off right around 2200rpms or so with the juice on. It is much more "rattley" on the highway with the juice on. I believe I read, either on this site or the page, that Edge has to shut the pilot injection off sooner due to the fact they command more fuel. The engine is not as quiet with the juice on either. I guess all trade offs that you need to decide if it is worth it. Also, with light throttle at high speeds, it really sounds like a rattle trap when you get in it and then back out of it. Mine has done this since installed as well. From the response I have gathered this is normal operation with the juice box, it is just that some don't notice or don't hear it.


With the juice box off, it is much quieter, throughout the whole rpm range. It is amazing how much quieter my truck idles without the juice box on....but I have got so used to the extra power, stock just feels like a dog, especially towing...


Bob





Most of the programs out there add timing, It's most probably the added timing that's responsible for the added noise.