Attention: TDR Forum Junkies 
its not a fuel problem (not including the VP44) i have a pusher pump at the tank drilled out banjo bolts. and the fittings on the fuel filter feed line have been taken out to 3/16". i have rock steady pressure all through the RPM range.
others have had thier VP's replaced, and the problem was still there. so i dont believe its the injection pump.
i think it is in the fuel managment of the ECM. its like its too sensitive, to throttle pressure and ramps off too quik. the only thing i can see to do, is put a patch in the ECM to de-sensitize the APPS and fuel ramps (good luck getting Cummins to do that though) or de-tune or boxes, under a certain boost level (taking away from spool-up none the less). the additional fuel, realy should feed off of throttle position in conjunction with boost. i will have to admit though, my truck did this before i fooled with it. just under a moderatly heavy load, not empty so it was never perfect.
these are things i plan to look at. i just havent had time. I need to look at what our boxes are telling the truck it has for boost. i think the problem lies here. we need find out whether it is fixed or varies as boost climbs and descends. i suspect that Edge's "smoke adjustment" between levels is doing just that. it backs off the signal to the truck or even allows it to see actual readings at low boost, then ramps it up to specific "fixed" values as the "box" starts to see boost. but still hiding the "actual" boost from the truck, with that predetermined "fixed" value, based on what level of control your on. in this case, if these fixed values dont drop back off under moderate or regular driving conditions (2 or 3PSI of boost) the truck is still seeing higher boost levels than it normaly would under that load. this gives you the hyper-active fuel delivery at low rpm's. thus bucking. more than likely the higher (or lower, however you look at it) the level of smoke control (less control) the more hyper the truck gets.
anyone out there that has had the TST PM3 COMP, would know what i am talking about. when that box is run on level 7 and up it shudders the truck HARD when you let off and it is real hyper or gitty, when trying to drive at a constant speed. cruse control is rendered useless too. i am anxious to see what the truck is seeing for boost readings with my box. (PM3) i suspect it is a fixed value. with the truck thinking it has about 15psi of boost, all the time. the PM is programed to start fuel delivery at 1PSI of boost. if this is the case, then the ECM would again be delivering more fuel than it was programed for, for those speeds, making the truck have more power but simultaneously be MORE touchy at lower speeds.
fool the boost you get a little bucking, add a fueling box you get even more..... see where this is going... add some timing, wow!!!
others have had thier VP's replaced, and the problem was still there. so i dont believe its the injection pump.
i think it is in the fuel managment of the ECM. its like its too sensitive, to throttle pressure and ramps off too quik. the only thing i can see to do, is put a patch in the ECM to de-sensitize the APPS and fuel ramps (good luck getting Cummins to do that though) or de-tune or boxes, under a certain boost level (taking away from spool-up none the less). the additional fuel, realy should feed off of throttle position in conjunction with boost. i will have to admit though, my truck did this before i fooled with it. just under a moderatly heavy load, not empty so it was never perfect.
these are things i plan to look at. i just havent had time. I need to look at what our boxes are telling the truck it has for boost. i think the problem lies here. we need find out whether it is fixed or varies as boost climbs and descends. i suspect that Edge's "smoke adjustment" between levels is doing just that. it backs off the signal to the truck or even allows it to see actual readings at low boost, then ramps it up to specific "fixed" values as the "box" starts to see boost. but still hiding the "actual" boost from the truck, with that predetermined "fixed" value, based on what level of control your on. in this case, if these fixed values dont drop back off under moderate or regular driving conditions (2 or 3PSI of boost) the truck is still seeing higher boost levels than it normaly would under that load. this gives you the hyper-active fuel delivery at low rpm's. thus bucking. more than likely the higher (or lower, however you look at it) the level of smoke control (less control) the more hyper the truck gets.
anyone out there that has had the TST PM3 COMP, would know what i am talking about. when that box is run on level 7 and up it shudders the truck HARD when you let off and it is real hyper or gitty, when trying to drive at a constant speed. cruse control is rendered useless too. i am anxious to see what the truck is seeing for boost readings with my box. (PM3) i suspect it is a fixed value. with the truck thinking it has about 15psi of boost, all the time. the PM is programed to start fuel delivery at 1PSI of boost. if this is the case, then the ECM would again be delivering more fuel than it was programed for, for those speeds, making the truck have more power but simultaneously be MORE touchy at lower speeds.
fool the boost you get a little bucking, add a fueling box you get even more..... see where this is going... add some timing, wow!!!
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