So, my cruise will maintain a perfect speed, but it seems that it "adjusts" itself so much that it becomes quite annoying. The only time the engine holds stead-fast is on any bit of grade...If you are on a flat stretch it becomes very active, active enough to make the boost gauge go up and down...alot. What is everyone else's cruise behave like? I have done the adjustment on the cable, leaving less than the 1mm allowance...what next?

 

Mike is it surging? or is it"speed up/coast down, speed up /coast down'....

 

I was having the same issue, however it would also idle low when first started and then speed up if I tapped the pedal a couple of times. I started using stanedine performance conditioner and after a few tanks both problems were solved.

 

No, i dont believe it surges...seems like that would result in a variance in speed. Its more like the speeding up, slowing down of the engine rpms...shouldn't it hold a little more steady?

 

The more I messed with my pump, the more my cruise messed up. Now the pump is close to maxed and the cruise doesn't work at all. Coincidence, who knows?

 

Dang, I wonder if it has something to do with me moving the adjustable rod on the pump to the inside hole? It makes the throttle much more sensitive to the pedal....

 

My cruise is quite anoying also. It can "work" intermittently, but is never steady (like a foot). It can occasionally get erratic and run away speeding faster (gradually, not like punching the accellerator), then you have to take it out of cruise. It also goes the other way sometimes, slowing down gradually. I haven't used it much lately, although I dig having cruise on long road trips which I do several times a year. I have noticed it fluctuate affecting the boost, you can just feel it trying to micro adjust. I had another first gen that did similar stuff, maybe not quite as bad and was more consistant on road trips. It is maddening. Fixing this is on my long list of to do's.

 

That was one of the first things I did when I noticed the cruise acting up. I enjoy the throttle reponse more than the cruise so I never pursued it.

 

I'm having the same problem as MountainBen,but it's only because I put a different ECM in while I'm trying to fix my original one.

 

mine won't work at anything less than 60 and if it does set below that it will be up to 60 in under a mile. It runs a steady RPM for the most part. tonight I had it set at 60 1700 ish RPM was kind of spaced out until I heard the turbo wining and notice it had pulled right up to 75 and was still climbing. I haven't had a chance to mess with it yet but it runs rather steady RPM most of the time.

 

Yes it should hold a steady RPM on level ground/consistant speed...

I could see where having increased fuel pressure or volume to the IP could result in this problem...

the cruise is supposed to regulate and provide a steady amount of fuel to the pump at the designed fuel pressure and flow rate( level ground/constant speed)...
if the pump is receivng a higher than designed fuel flow, it might cause rpms to go up, this would trigger the cruise to slow the flow of fuel,rpms go down, then it would increase fuel flow again, rpms go up, and so on and so on... it would make sense that the more"sensitive" the pedal becomes, the more obvious this problem would be....
this isnt based on any scientific knowledge, just theorizing here.....
and I could see how it might be a small enough change in fuel flow as to not make a noticable difference on the speedo, but be enough to trigger the cruise control..
If you have a fuel pressure gauge, you could kinda test this idea by seeing if the fuel pressure fluctuates with the RPM's while the cruise is engageed..

 

Same thing happened on mine, its because of the "turned up" pump, makes the throttle much more sensitive than the cruise was designed around. So to fix it, the 2nd gen boys have this problem also, is to restrict the vacuum going to the actuator with something really small like a spray straw off of a can of brake cleaner. Do this at the inlet to the actuator.

That should fix it.

 

Speed Control - Adaptive Strategy

NO: 08-16-95 Rev. A

GROUP: Electrical

DATE: Oct. 6, 1995
SUBJECT:
Speed Control
Overshoot/Undershoot
During Initial Set Speed Selection

NOTE : THIS BULLETIN SUPERSEDES TECHNICAL SERVICE BULLETIN 08-16-95, DATED APR. 14, 1995, WHICH SHOULD BE REMOVED FROM YOUR FILES. REVISIONS INCLUDE ADDITIONAL MODELS AND ADDITIONAL INFORMATION IN THE DISCUSSION. ONLY THE REVISIONS IN THE DISCUSSION ARE HIGHLIGHTED WITH **ASTERISKS**.

MODELS:

1989 - 1995 (AA) Spirit/Acclaim/LeBaron Sedan
1989 - 1996 (AB) Ram Van/Wagon
1989 - 1993 (AC) Dynasty/New Yorker/New Yorker Salon
1989 - 1993 (AD) Ram Pickup/Ramcharger
1989 - 1993 (AG) Daytona
1989 (AH) Lancer/LeBaron GTS
1989 - 1995 (AJ) LeBaron Coupe/LeBaron Convertible
1989 (AK) Aries/Reliant
1989 - 1996 (AN) Dakota/Dakota Cab & Chassis
1989 - 1994 (AP) Shadow/Shadow Convertible/Sundance
1990 - 1991 (AQ) Chrysler Maserati TC
1989 - 1995 (AS) Town & Country/Caravan/Voyager
1990 - 1993 (AY) Imperial/New Yorker Fifth Avenue
1991 - 1992 (BB) Monaco/Premier
1994 - 1996 (BR) Ram Pickup
1993 - 1995 (ES) Chrysler Voyager (European Market)
1995 - 1996 (FJ) Sebring/Avenger/Talon
1996 (GS) Chrysler Voyager (European Market)
1995 - 1996 (JA) Cirrus/Stratus/Breeze
1996 (JX) Sebring Convertible
1993 - 1996 (LH) Concorde/Intrepid/LHS/New Yorker/Vision
1991 - 1992 (MJ) Comanche
1996 (NS) Town & Country/Caravan/Voyager
1995 - 1996 (PL) Neon
1991 - 1996 (XJ) Cherokee/Wagoneer
1993 - 1996 (ZG) Grand Cherokee (European Market)
1993 - 1996 (ZJ) Grand Cherokee/Grand Wagoneer

DISCUSSION:

If the vehicle operator **repeatedly** presses and releases the SET button with their foot off of the accelerator (a "lift foot set" to begin speed control operation), the vehicle may accelerate and exceed the desired set speed by up to 5 MPH (8 km/h) and then decelerate to less than the desired set speed before finally achieving the desired set speed.

The speed control has an adaptive strategy (ability to learn) that compensates for vehicle-to-vehicle variations in speed control cable lengths. When the speed control is set with the vehicle operators foot off of the accelerator pedal, the speed control "thinks" there is excessive speed control cable slack and adapts (learns). If "lift foot sets" are continually used, the speed control overshoot/undershoot condition will develop.

To "unlearn" the overshoot/undershoot condition, the vehicle operator has to press and release the SET button while maintaining the desired set speed with the accelerator pedal (not decelerating or accelerating), and then turn the speed control switch to the OFF position **(or press the CANCEL button, if equipped) after the speed control has been engaged for 10 seconds or longer.** This procedure must be performed approximately 10-15 times to completely unlearn the overshoot/undershoot condition.

If the speed control operation procedure outlined in the Owners Manual is followed, the overshoot/undershoot condition will not occur. Please review the proper set procedure with the vehicle operator.

POLICY: Information Only
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Terms of Use

 

Speed Control - Surge at highway Speeds
NO.:
08-07-93 Rev. A

GROUP:
Electrical

DATE:
Mar. 19, 1993

SUBJECT:
Speed Control Surge

NOTE:
THIS BULLETIN SUPERSEDES TECHNICAL SERVICE BULLETIN 08-07-93 WHICH SHOULD BE REMOVED FROM YOUR FILES. ALL REVISIONS ARE HIGHLIGHTED WITH **ASTERISKS**.

NOTE:
THIS BULLETIN APPLIES ONLY TO FOUR WHEEL DRIVE VEHICLES EQUIPPED WITH THE CUMMINS DIESEL ENGINE.

MODELS:

1992-93 (AD) Ram Pickup/Ram Cab Chassis

SYMPTOM/CONDITION:

Some vehicles may exhibit a speed variation at highway speeds while the speed control is engaged.

DIAGNOSIS:
1. Perform the speed control system test as outlined in Section 8H of the service manual. If no problems are found during the test, proceed to step 2.

2. On 1992 vehicles verify that the vehicle is equipped with the correct speed control servo and cable for the Powertrain Control Module (SBEC) that is installed, Refer to the chart below and make sure that the Powertrain Control Module, servo and cable match.

POWERTRAIN CONTROL MODULE REFERENCE CHART

SBEC Part No. Servo Part No. Cable Part No.

56027570 53007954 (Zemco) **4428787**
56027571 53007954 (Zemco) **4428787**
56027572 53007954 (Zemco) **4428787**
96027573 53007954 (Zemco) **4428787**

POWERTRAIN CONTROL MODULE REFERENCE CHART CONT'D

SBEC Part No. Servo Part No. Cable Part No.

56027081 53009315 (Eaton) **52078330**
56028082 53009315 (Eaton) **52078330**
56027083 53009315 (Eaton) **52078330**
56027084 53009315 (Eaton) **52078330**

3. If no problems have been found to this point, the speedometer drive gear on the output shaft of the NP 205 transfer case may be at fault. Remove the speed sensor, adapter and the speedometer drive gear. Carefully inspect the speedometer drive gear while rotating the output shaft. Any cuts or irregularities on the gear can cause a speed sensor signal variation. If any irregularities are present, proceed to the repair procedure.

PARTS REQUIRED:

1 Speedometer Drive Gear 3732038

REPAIR PROCEDURE:

Replace the speedometer drive gear using the procedures outlined in Section 21 of the Rear Wheel Drive Dodge Truck Service Manual.
POLICY:
Reimbursable within the provisions of the warranty.

TIME ALLOWANCE:

Labor Operation No. 21-97-10-91................................0.6 Hrs.

FAILURE CODE:
58 - Internal Defect