acceleration lag

Discussion of the 5.7L-6.1L-6.4L HEMIs.

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roadbyte
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acceleration lag

Post by roadbyte » Mon Aug 09, 2004 10:20 am

I have notice the following problem with the truck. There seems to be lag before the engine spools up if the speed is between 45-60 Mph when I try to accelerate not hard but slow steady acceleration :( the truck seems to lag before it starts to speedup.

Has anyone else seen this type of problem with the 2004, 1500 5.7 Quad cab 2X4

Thank you
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speed707900
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Post by speed707900 » Mon Aug 09, 2004 10:52 am

well anyone with the new 5.7s has similar issues. its kinda normal. i dont know about what your talking about at that higher speed but the acclerator system is odd...its not the ususual linked system..its all electronic and sometimes, say if you are at a dead stop, and you floor it all the way..it may hesitate for half a second or more before it really goes for it...it just takes a while for it to compute what its doing.

anyone else have anything more on this? i myself would like to know
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JakeDogg
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Post by JakeDogg » Mon Aug 09, 2004 11:22 am

With this automatic transmission I have found out that there are two modes. Slushbox overdrive with moderate acceleration, or floor it and haul butt! If you moderately ease into the gas, it is always going to lag and shift into overdrive.
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Rampant
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Post by Rampant » Mon Aug 09, 2004 11:59 am

there is some slop in the fly by wire system and the economy mode to deal with. When at a stop the truck will drop to 500 rpm or so-economy mode, then has to change out of it to accelerate. Some people have taken the play out of the accelerator with a zip tie either in the pedal or in the wire under the hood. If you change out the intake it seems to take out most of the accelerator lag. If you have some one help you can check, when you hit the gas with the truck in park go over to the stock filter and you can hear it sucking air like it is not getting enough.

SoCalHemi04

Post by SoCalHemi04 » Mon Aug 09, 2004 8:47 pm

i did the tie-wrap trick on the throttle cable and had a noticeable improvement.

Rampant
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Post by Rampant » Mon Aug 09, 2004 8:53 pm

The only problem is I can't tell how much is from converter and how much from mit. I think alittle of each, but the hesitation is almost entirely gone any left is in electronics.

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Post by scottm » Tue Aug 10, 2004 12:12 pm

My wife's 2004 Grand Prix is throttle-by-wire, too.
There is a clear delay between the pedal and revs.
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roadbyte
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Lag

Post by roadbyte » Fri Aug 13, 2004 8:59 am

After talking to the stealer I mean dealer the comments are the engine and speed and ground speed is increasing but the converter is not lock-up. It takes awhile before the convert locks and the power is transferred to the rear wheels.

He is basically correct on that statement but the engine it self is lacking power in 1800-2000 (approximate) rpm range. It appears that the electronics are have a major break down in communications as you try to gradual accelerate After you have your foot into so much than the power curve kicks in and the way you go.

If you take another vehicle out for a test drive compare the difference in the power curve at different speeds. What I mean by the test the gradual increase in foot pressure on the gas pedal compare to the responsive of the vehicle speed and power.

The Hemi has more than enough power if you put your foot into floor but it should have very smoot power curve not one that has large dead spot.
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GreenbeanZ28
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Post by GreenbeanZ28 » Fri Aug 13, 2004 10:29 am

I think it lacks power to 3000, forget 2000.
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Post by Hemidakota » Fri Aug 13, 2004 10:38 am

This is an old problem that stemmed from the first days of production in the Dakotas. The 4.7 was matted with the RE45 slush MB tranny.

Since I don't have the complete archives of what transpired since then, my only insights was to turn off the overdrive button and see if someone can reflash the tranny ecu box in removing the 'pause' to shift.

There is a guy out in LA (MOPAR uses him for custom flashes) who use to the custom flashes but his name escapes me at this time. He also has the map for the tranny.
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roadbyte
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Update

Post by roadbyte » Tue Aug 17, 2004 1:44 pm

I give the dealer my truck last night for one more attempt to fix it.

List of problems that was given to the dealer the truck is less than 30 days old.

1) Cruise control would not set twice had to pull off the road and shut the truck off and restart it.
2) Would not engage reserve gear 8 time
3) The truck is sluggish
4) Driver set is broken
5) Clicking sound coming from the driver’s side engine compartment

The guy at the dealer tried to say the sluggishness might be caused by the 5 speed Transmission my reply to him was give me a standard transmission. At least confirmed the problem with the engine.
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cue244
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Post by cue244 » Tue Aug 17, 2004 11:39 pm

Rampant, what is the trick with the zip tie? Thanks!!
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usedtobert
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Post by usedtobert » Wed Aug 18, 2004 10:24 am

Mike Leech does some custom tuning for the 4.7L engine and this may be who your refering to. He does good work.

I test drove a 2000 4.7L auto with 3.92 gears before opting for the R/T and it was definitly sluggish unless you layed it to the wood. The R/T on the other hand was smooth and strong all the way till 70 and then it hit a dead spot (stock) for a second.

Dodge made a Mistake getting rid of the 42RE and 46RE. You do NOT put luxury trannys behind performance engines.

Rampant
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Post by Rampant » Wed Aug 18, 2004 1:11 pm

The zip tie trick is basically people have used zip ties in either the cab or engine compartment to take some of the slack out of the throttle cable. Yes I know it is fly by wire. In the cab they are using a zip tie under the gas pedal so there i less movement. In the engine compartment I believe the wire is under the battery tray and ther is a place to put a zip tie that takes out some of the slack in the cable that controls the throttle butterfly. I will see if I can find the instructions and send them to you cue244. I have not done this. I talk to the dealership mechanic about some of this stuff and he does not like it. Not saying it will not work or not to do it, just that my dealership is cool with me doing stuff if I talk to them about it first.

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Post by cue244 » Wed Aug 18, 2004 6:10 pm

Thanks for the info Rampant!!
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Goose
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Post by Goose » Thu Aug 19, 2004 9:32 am

I am not the most advanced in terms of the tech side of things but..

What you guys are talking about may also have something to do with the "multispeed" transmission. Essentially 2nd gear has 2 different ratios. Accellerating from a stop uses a 1.67:1 ratio but when you punch it from a cruise it drops into a 1.50:1 ratio. The tranny is also "adaptive" to your driving. I'm hoping the '04' Superchips programmer will address some of this....if it ever arrives. This all only speaks to the 5speed auto of course.

Good luck and I'll be watching for ideas as well! 8)
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roadbyte
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Dodge

Post by roadbyte » Tue Aug 24, 2004 9:09 am

Good Morning Everyone,

I just finished talking to Dodge customer service and I was told that no one else has every reported a problem about the acceleration lag or sluggish in the truck when you roll into the gas pedal to pick up speed say from about 50 to 75 miles per hour.

I would like to know if anyone else has reported to this problem to Dodge directly if so please let me know if not please report the issue to Dodge at the following number.

1-800-992-1992

Ask for case number also this way we can track what Dodge is doing not just on this issue any other issues also.

Don
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Rampant
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Post by Rampant » Thu Aug 26, 2004 7:58 am

Alright try this one. According to the tech manual after you reset the computer the throttle needs to be recalibrated. (another guy found this in the book, not me) Turn the key to run without starting. Wait for bells, push the gas pedal down at normal speed and then let up at same speed. Now start the truck. It will idle at 800rpm and should respond better. Some think it is all mental, others say it works great. Try it and post up.

Rampant
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Post by Rampant » Fri Sep 10, 2004 6:52 am

So I guess the people complaining about the acceleration lag were not willing to take two minutes to attempt a free fix?

roadbyte
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Free Fix

Post by roadbyte » Fri Sep 10, 2004 3:43 pm

First the free fixes is great but do you agree that if there is design flaw from Dodge that Dodge should provide the fix for everyone.

At the present I have requested meeting with the local District Manager from Dodge to address this problem with me.

After talking to the Dealer and ask him to check the starhotline there is no fixes at the present time in the pipeline as far as he knows.

IMHO Dodge needs to address this issue and give soultion to the problem, other wise what is being portrayed on TV is just little false in my eyes.


I was told the District manager should call me by monday. I will keep you updated.
2003 QC DRW HO 6SP 3:73 Silver Born on Date 03/07/03

SoCalHemi04

throttle responce improvment

Post by SoCalHemi04 » Sun Sep 12, 2004 10:49 am

I did the throttle calibration trick and boy what a differance! I am the happiest with this mod and it cost nothing. Heres how to calib it.
1. turn key to on but don't start the engine.
2. wait till the chimes to stop and floor the gas peddle at a rapid pace.
3. while holding the peddle down turn the key to off.
This mod has worked on both of my Hemis and a friends 04 also.

KGHemi

Post by KGHemi » Wed Sep 22, 2004 12:02 pm

I did the throttle trick with the ignition key and that worked perfectly.
No more falling on its face when I get into it.

TheRedneckWay

Post by TheRedneckWay » Fri Sep 24, 2004 12:42 am

does this throttle calibration trick last permanently, or does it need to be performed each time you drive?

TheRedneckWay

Post by TheRedneckWay » Sat Sep 25, 2004 6:43 am

i tried this throttle calibration trick yesterday, and its not my imagination, THIS REALLY WORKS. If it will make my huge 4x4 HEMI with huge tires haul butt, it would make a 4x2 HEMI scream!!!

glz927
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Hesitation

Post by glz927 » Sat Sep 25, 2004 8:26 am

Do you have to disconnect battery for this fix or can I just hop into my Ram and do it? :-?
I need gas again?

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