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-   -   Sluggish Between 35 and 40mph (http://www.jeepgarage.org/f183/sluggish-between-35-and-40mph-55674.html)

therock2 03-02-2013 09:43 AM

Sluggish Between 35 and 40mph
 
I have a 5.7L Hemi Overland and there's a slight hesitation between 35 and 40 mph and I"m not sure what is causing it. During acceleration I can feel a slight "bogging" sensation and whenever I look at my speedometer it's always between these two speeds. I've replaced the throttle body but it did this before I changed it. EGR? Map Sensor?

Any ideas?

WK2009AN 03-03-2013 08:14 AM

Re: Sluggish Between 35 and 40mph
 
Not sure buddy but I heard somewhere that there is a natural sluggish spot there, the only area of the rpm spectrum where theres some lag, not sure what causes it, im sure someone else can elaborate???

therock2 03-03-2013 11:06 AM

Re: Sluggish Between 35 and 40mph
 
It's the weirdest thing. It's good to know I'm not the only one that has experience this. I have also replaced the plugs and PCV valve (regular maintenance) along with Seafoam in the gas tank and oil reservoir. I'm looking forward to hearing about other members' experience with this. Hopefully there's a solution.

dmsfun 03-03-2013 12:59 PM

Re: Sluggish Between 35 and 40mph
 
I had that with stock tune. Intune and CMR tuning makes a world of difference.
Last week I loaded the stock tune and it still does that. With the 87 Octane CMR tune, it is like a whole new engine compared to stock tune with 89 Oct.

SvenskaJeepGuy 03-03-2013 01:04 PM

Re: Sluggish Between 35 and 40mph
 
I know on the 4.7 there is a tsb to fox this and it works. Had it done on mine but i dont know about the hemi

4.whoa 03-03-2013 01:18 PM

Re: Sluggish Between 35 and 40mph
 
when you do seafoam the MOST IMPORTANT one is in the intake/vac line. this is what clears the most crap out,in the gas helps more with injectors.
try driving in tow mode, it keeps mds off and changes shift points slightly. thats what i did before I got my DS.

06HemiLtd 03-03-2013 07:01 PM

Re: Sluggish Between 35 and 40mph
 
4.Whoa kind of hit on it. 40 mph is an area that my hemi used to be weird at too. Seemed like it'd take it a second to respond to throttle input. I installed a magnaflow muffler and I could actually hear the MDS kicking in and out when i was cruising around 40 mph. I bought a Predator and loaded the 93 canned tune and disabled the MDS function. It completely corrected the issue. It is a beast now and hauls no matter what speed I'm at.

jeepgcoman 03-03-2013 08:25 PM

Re: Sluggish Between 35 and 40mph
 
Or, you could get the Superchips tuner with the Advanced Transmission Tuning Application, and set the entire transmission up the way you want it for your needs....up/down shift schedules, and torque management. If done right it gets rid of most of the issues we have all had with the 545RFE tranny.

GCHemi 03-04-2013 11:34 AM

Re: Sluggish Between 35 and 40mph
 
Wow, I'm glad that I read this thread.

Another Hemi owner here, I've noticed this too and so has my wife(insert joke here).

So the answer here is to remap or put the power down over this awkward spot?

therock2 03-04-2013 12:53 PM

Re: Sluggish Between 35 and 40mph
 
It looks like a Diablosport I-1000 is next on the list. (alone with a CMR tune)

4.whoa 03-04-2013 05:03 PM

Re: Sluggish Between 35 and 40mph
 
If you havent done it ,and you have some miles it,it might be a not be a bad idea to change the EGR also.mine didnt give any codes but i had some surging that stopped when i changed it.

A CMR is definately worth it, but even canned tunes and fiddling with trans adjustments youself can help alot with pepi-ness :-)

therock2 03-04-2013 06:01 PM

Re: Sluggish Between 35 and 40mph
 
I just finished changing the EGR this afternoon. I bought it with 92K on it and it now has 94.5K so I figured it was overdue for a change anyway. I also just ordered a new MAP sensor and will be replacing it next week. It's snowing pretty hard right now so I'll have to wait to try it out on my way to work. I'll report back in a day or so with any changes/improvements with just the new EGR.


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