Cruise Control Surging Issue - Cash Reward to Anyone That Can Help Me Fix it!

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drewkeen

Old School
2003 Dodge with the 5.9 HO and 48RE transmission. Nothing has recently changed to cause this, the truck did not do this when I first bought it. It got a Smarty tune and did this. I then flashed it back to stock and reflashed the Smarty and it fixed the issue. I should have left well enough alone, but I thought HP Tuners would be better. Since it also acted the same way with the Smarty I can't really blame the HP Tuners. This does lead me to believe it is something in the electronics/tune though.

When you set cruise the truck accelerates a couple of MPH, then slows down, then speeds back up again. It constantly varies by several MPH and can't figure out what the problem is and keeps doing it. Seems to be worse on flat ground or up hills and seems to calm down a bit doing downhill.

I have HP Tuners and have generated and flashed stock tunes back in the truck multiple times along with the performance tune for the truck. Nothing really changes, although it is a bit more sensitive with the tune because of the extra power.

I cleaned all of the grounds in the engine bay and on the batteries. I also got upgraded battery cables as the stock connector cable was failing on the ends and needed repair.

I replaced my FCA with a brand new Bosch one, no change.

I tried a restrictor in the line going to the servo, no change at first, but as I made it more of a restriction the issue had a bit longer of a delay to begin doing this, but then went back to doing the same thing.

I have an Edge insight and rail pressure seems to stay steady on it as well as following the desired in my HP Tuners Logs. I can do data logs of any parameters needed that HP Tuners can capture as well. The Edge also shows the TPS to be linear and steady as the cruise depresses and releases the accelerator pedal.

I have not replaced the servo, but it seems like this would be throwing parts at the issue for no reason - unless these are a common failure point.


Not sure what to really try next. I'll PayPal $25 to anyone that can help me in figuring this out. The only other thing I was thinking about doing was asking my local dealer to do a stock reflash on the truck to see if that remedied anything.
 
Really common issue with these trucks believe it or not. Very few have solved it. Good luck on your search.
 
My '03 used to surge like crazy with Flux 7s, Edge EZ, big single CP3, SB66, and a Smarty. Marco made some adjustments thru beta files, which improved it but it never went away. I bet if you could find someone to wash the ECM (usually only the factory has wash files), your issues would be resolved. This was before HP Tuner days as well. I ran the Smarty bc it was the best thing around, and Bob and Marco were supporting a bunch of development work.

Sent from my SM-G960U using Tapatalk
 
Mine did it a lot and it bugged the hell out of me. Try a different FCA (modded or stock), or go back to bone stock tune, and see what happens.
 
Some 03's use a vacuum pod to control the cruise. I've seen them fail and leak which can cause the surging your experiencing.
 
RascalMafia said:
My '03 used to surge like crazy with Flux 7s, Edge EZ, big single CP3, SB66, and a Smarty. Marco made some adjustments thru beta files, which improved it but it never went away. I bet if you could find someone to wash the ECM (usually only the factory has wash files), your issues would be resolved. This was before HP Tuner days as well. I ran the Smarty bc it was the best thing around, and Bob and Marco were supporting a bunch of development work.

Sent from my SM-G960U using Tapatalk
Click to expand...


Any idea what on the adjustments he made were?

I might have to take it to Dodge to wash it, or do you mean the actual production factory?

I sent an email over to HP Tuners, they replied back that is was probably the tune, then I replied back stating that it happened like it did and even remained when their stock generated file was rewritten. Hopefully I will get a helpful answer back from them.
 
khaoskustoms said:
Some 03's use a vacuum pod to control the cruise. I've seen them fail and leak which can cause the surging your experiencing.
Click to expand...

Where is the vacuum pod? Do you mean the little pump on the passenger side firewall?

Truck still had a ton of vacuum at the Servo when I pulled the hose off the install the restriction even after it had been shut off for a couple of minutes.
 
ATS Dual CP3 kit with stock CP3. It originally happened with just the stock CP3 as well.

We tried to lower rail pressure and also to keep it mostly constant to see if that was an issue with no change.
 
RascalMafia said:
My '03 used to surge like crazy with Flux 7s, Edge EZ, big single CP3, SB66, and a Smarty. Marco made some adjustments thru beta files, which improved it but it never went away. I bet if you could find someone to wash the ECM (usually only the factory has wash files), your issues would be resolved. This was before HP Tuner days as well. I ran the Smarty bc it was the best thing around, and Bob and Marco were supporting a bunch of development work.

Sent from my SM-G960U using Tapatalk
Click to expand...

The good days Roy. Hope all is well. You were and are kicking ass and taking names in life.

Good guy you are.

:woohoo:
 
drewkeen said:
Where is the vacuum pod? Do you mean the little pump on the passenger side firewall?

Truck still had a ton of vacuum at the Servo when I pulled the hose off the install the restriction even after it had been shut off for a couple of minutes.
Click to expand...

The servo/pod that pulls the cable is what I mean. it has a vent port that could be malfunctioning. I had a 12v truck that would surge and randomly accelerate when the cruise was on. Replaced the servo/pod and it was good to go.
 
I have 2003 with a smarty on it. Mine will do the same thing. To fix it I turned down the throttle sensitivity to like 55% or so. That made the cruise much better on mine. I don't know if HP tuners will let you do that or not. But I would try to make the throttle less responsive and see if that makes it better.
 
I also have an 03 with hp tuners. I wrote multiple tunes for it and my "street" tune has the pedal map backed way down from my other tunes. It makes a world of difference. May want to try that.

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Thanks Bob, hope all is well in the PNW! Those were the good old days, I thoroughly enjoyed doing all of that testing with you guys!
Bob Wagner said:
The good days Roy. Hope all is well. You were and are kicking ass and taking names in life.

Good guy you are.

:woohoo:
Click to expand...

Sent from my SM-G960U using Tapatalk
 
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I have a lot of experience with this, but sadly i have never fully cured it.

I have had this problem with 2 different pumps, 3 sets of injectors, and every combination you can think of. its not in the injectors or the map sensor. I have several logs that show it happening between 0 and 30 mm3.

Mine only does it on cruise control and it has to be going downhill somewhat.

When i am on CC i can anticipate it coming after i crest a hill or mountain. I have to tap the brakes or cancel cruise, then re engage. So in other words it only does it when the engine is at 5% load or less.

swapping injectors, pumps, FCA's and MAP's does nothing for it. The best you can do is make sure all your fuel quantity cells are as smooth as possible in your tune and as stated above, the less aggressive your throttle is the more manageable it is.

To the OP, your truck has vacuum based cruise and mine is all in the ECM so these trucks share the same symptoms with different inputs. I have tried countless tunes, speed sensors etc etc and all i can tell you is it never really goes away.
 
Is there a way you can change the values of the PID controller in the ECM for the cruise? It sounds like it keeps overshooting and needs to be tuned.
 
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