CRUISE CONTROL SURGE

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Has anyone experienced a problem with the cruise control surging? Mine seems to not be able to settle down on a constant speed, it continually is speeding up and slowing down about 3 mph. This is more noticable at lower highway speeds, 55 mph, than at freeway speeds. Dealer sez this is "normal" and there is no adjustment to be made.

My old '94 cummins 5 speed 4x4 was as steady and the speed hardly sagged even on hills.

Any information/ideas are appreciated.

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'01 HO, 6 speed, QC, 4x4, camper package

 

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Sounds like you have a vacuum leak. Check out John Holmes' comments> I copied this from the "TDR Index" section:

Cruise Control:
Issue 23, Page 76d (Ranch Dressing) John Holmes finds a vacuum leak that
would affect the cruise control.

Also, check out this posting: https://www.turbodieselregister.com/ubb//Forum4/HTML/002355.html

 

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My truck does the same thing. I never have noticed a change in the speedo but I hear the turbo spool up and down. It seems to be associated with minor dips or bumps in the road. The problem seems to go away for the most part around 68-70 mph. I'll look into the vacuum end and see what I can come up with. I just think the gizmo is to damn sensitive. The roads are flat down here except for the occasional bridge or overpass.

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2001 ,2500 ST Light Driftwood QC,LB,ETH,6 speed,3. 54 LS, LT265/75R16, TrTGr, Smoothie, Step Sheilds, C. Crane Truck Antenna, Line-X bedliner and rocker panels.

 

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Cocahoe,I guess I need to get to Denham Springs so i can see a flat road in Louisiana. #ad
#ad
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At least my shocks get a good workout #ad
#ad
#ad

BTW I like the name, another saltwater fisherman like myself.

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1994 Ram 2500 Laramie SLT, 12 valve, 2WD, Auto. Ranch Hand steel brush guard, Westin Step bars. sprayed in liner. K&N RE-0880 filter, silencer ring removed, Flowmaster muffler, chrome turn down pipe out the side, Velvet ride shackles. www.gitchesumatfreeweb.com

 

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Chuckar, there was a hunt problem with the 99 and I think a reflash for the PCM to cure it. Also a do it yourself cure which involves setting the cruise while on level ground with the acc. pedal steady, then turn it off,wait 10-15 seconds, repeat. You must do this 10 to 15 times for the computer to "un-leaarn the overshoot-undershoot. They say it is caused by setting the cruise with the foot off the acc. ? I know it sounds silly but it works, at least on the 99.

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White 99 3500, QC, 3:55, auto. most options except leather, Line-X bed liner, fiberglass running boards Rancho 9000s, bug shield and window vents, black vented 5th wheel tailgate, 100 gal. aux. fuel tank.

 

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The 2nd wave of 2001's have a change to the CC noted as "servo-less cruise" or something to that effect if my memory serves correctly. Anyone know what this means? A possible fix for the surge?

Shelby

 

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Chuckar, I had the same problem in my 98. There is a TSB out for it. I took it to the dealer, they reflashed the computer, 30 minutes later the cruise was working perfectly.


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Randy Jones, San Antonio, TX, 98 1/2 QC, 4X4, American Racing BAJA's, 285/75/16, Amsoil throughout

 

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My '95 was steady as could be. I got my '99 and was a totally different story. I live on the south side of Monument hill on I-25 in Colorado. The on ramp is at the bottom of the hill, I could get the cruise set shortly after the acc. lane ended (75mph), and, if I didn't watch it, was doing 90+ by the time I got to the top. Unnerving. The dealer couldn't help, tried the reflash, nothing. Then I read about not setting the cruise unless the accelerator is "engaged". Since I have been setting the accelerator correctly, I've had no problems. But, the symtoms before were simply an acceleration after setting the cruise. If you waited the acceleration out, which I did a few times, the speed would eventually drop back to the set speed, then hold constant. This doesn't sound like what you experience, so my bet would be the reflash mentioned in the TSB.

 

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Originally posted by Craig S:
I live on the south side of Monument hill on I-25 in Colorado. The on ramp is at the bottom of the hill, I could get the cruise set shortly after the acc. lane ended (75mph), and, if I didn't watch it, was doing 90+ by the time I got to the top. Unnerving.

<font color=blue>Don't try that in the wintertime! #ad
Thats a nasty hill from time to time, but then so is Happy Canyon in the wintertime.
I used to live in CastleRock is the only reason I am chiming in..... seen some nasty wrecks on I-25 while I lived there.


[This message has been edited by KatDiesel (edited 07-19-2000). ]

 

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Thanks for the input guys!

I will look/check for vacuum leaks, and try the "do-it-yourself" reprogramming. That will give me something to do on my long commutes!

I have the same problem of immediate overshoot upon engaging the cruise, and it sounds like the flash or manual programming will cure that problem, at least.

In regards to the larger injectors being a problem, maybe I will have to live with the constant "hunting" I experience while driving on the straigh and level.

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'01 HO, 6 speed, QC, 4x4, camper package

 

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Originally posted by gitchesum:
Cocahoe,I guess I need to get to Denham Springs so i can see a flat road in Louisiana.

Now you know what I meant by a flat road. Pot holes, tank traps, gullys, down trees, beer cans and the occasional stray cow or nutria do not make for hills. Instead of a grill guard, I think I need a bonafied cow catcher off of a train. It would also come in handy for the occasional PowerScroat that clogs the highway.



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2001 ,2500 ST Light Driftwood QC,LB,ETH,6 speed,3. 54 LS, LT265/75R16, TrTGr, Smoothie, Step Sheilds, C. Crane Truck Antenna, Line-X bedliner and rocker panels.

 

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My 98. 5 also had that problem. Dealer argued that there was nothing wrong. After getting "upset" with him, he put in a new EPROM and said that there was an update. That seemed to fix the problem.

 

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Hmmm, Wonder if this is one of the reasons the 2001. 5 trucks will have a true digital speed control instead of the vacuum unit?

Mick2500