Surging while driving

[Krlspokane12]

Hey guys, I hope everyone had a nice holiday season.  I believe that I have another random electrical gremlin but not sure where to start.  So, it started the other morning on the way to the office, the truck started randomly surging as I was cruising down the interstate.  I was traveling between 65 and 70mph, and it feels like the truck is accelerating on it own.  I can hear the engine raise RPM’s about 100 RPM and I can feel the truck accelerate for about .5- 1 sec, then it goes back to normal and then it happens again.  It is totally random, sometimes it happens at slower speeds and sometimes it only happens when driving at highway speeds, and sometimes it does not happen at all.  I noticed this morning that it was still surging even while I was giving it throttle while driving.  So, I’m at a loss here since there is no CEL or codes. The VP is new and has about 6k miles on it, I replaced the APPS last summer, the ECM is new, the batteries are new, the battery cables are new.  I also have not noticed any changes in the gauges, they all still work and seem to always be functioning correctly. Except sometimes the lift pump pressure is low, it stays at 11psi and wont go up to 15 where it normally is, unless I shut the truck off and start it again, then the pressure will be 15, but again this does not happen all the time.  Sorry for rambling and I hope yall can make sense of this.  I’m just not sure what rabbit hole to jump down yet.

[Silverwolf2691]

Check the alternator for having AC noise. Need a volt meter with AC volts capability. I don't remember the limit off hand but 0.08 sounds right..

Edited January 31, 2022 by Silverwolf2691

[Krlspokane12]

Okay thanks, I will try to get that checked tonight.  The alternator is new so many i got a bad reman. I was also thinking of resetting the APPS, not sure if that will make a difference or not.

[jlwelding]

Resetting should be done when batterys have been disconnected for sure. I had a similar surge while using accelerator, when cruise control on it stopped surging, my vp was going out.

[Krlspokane12]

Okay, I have reset the APPS.  See if it makes a difference in the morning.   I could not test the alternator since i cant find my multimeter, it must have grown legs.  I will try to find it this weekend and test to see if there is any AC noise coming from the alternator.  I was thinking about it today and correct me if I'm wrong.  Could this be a VP issue caused by the wire tap from the Quadzilla?  The last few times this has happened was after a hard acceleration where the pump tap was engaged from the Quadzilla (running tune 4 of 6). There are custom tunes based on input from you guys (much appreciated)  So today at lunch I lowered the power setting to #2, I had no issues what so ever at all.  I shut the truck off probably 4 times making different stops during lunch and nothing changed, the truck ran flawless.  Also, on the way home cruising on the interstate, no surging, it never missed a beat. So this is either a coincidence or it really is that random,  let me know your thoughts.  I plan on doing the the W-T ground mod this weekend since I have been planning on doing it for awhile, but not sure if might help solve this issue or any of the other weird dodge wiring issues I'm having, but that is a topic for another post. 

[Mopar1973Man]

21 hours ago, Krlspokane12 said:

I was traveling between 65 and 70mph, and it feels like the truck is accelerating on it own.  I can hear the engine raise RPM’s about 100 RPM and I can feel the truck accelerate for about .5- 1 sec, then it goes back to normal and then it happens again.

Grab a live data tool and monitor the TPS (APPS signal) and engine load. I wanna see if the something else is push the fueling command or is it just a poor quality APPS sensor. 

 

11 hours ago, Krlspokane12 said:

Could this be a VP issue caused by the wire tap from the Quadzilla?

Unplug the Quadzilla main plug for a temporary moment and the turn the key on (not running) and measure the wire tap voltage be sure it same as the battery voltage. This will ensure the tap is good connection and that the VP44 is showing fuel solenoid voltage on the wire tap. Its working if battery voltage is at the wire tap.

 

Another odd one that happen to me is verify the Quadzilla ground is solid I had my truck buck and do weird things when that bolt loosen up for the Quadzilla ground. 

 

11 hours ago, Krlspokane12 said:

I plan on doing the the W-T ground mod this weekend since I have been planning on doing it for awhile, but not sure if might help solve this issue or any of the other weird dodge wiring issues I'm having

AC noise does all kind of weird things. Like my 2002 Dodge (Beast) on the cruise control would randomly speed up and slow down. This is the AC noise from the alternator as the electrical demand went up with the heater blower, big headlights, etc the problem got worse. After doing the W-T ground wire mod the noise was reduced to a mere 11mV AC were about 50 mV AC most people start having random issues because the AC noise pollutes the hall effect sensors like speed sensors on the axles, speeds sensors on the transmission (hence the 3rd & 4th gear lock and unlock issue), this can even pollute the crank sensor signal so the cruise control will surge upwards past the set point and down below the set point because of AC noise pollution. The ground wire mod most the alternator charge lead to the passenger battery and the main grounds for the ECM and VP44 to the block and possible a secondary ground from the driver battery if done like my article. Takes about 2 hours to do the mod and I've done dozens of them and all worked perfectly. Now I've had a few issues with high load accessories like winch popping circuit breakers and fuses for the alternator but that not W-T Mod's fault its a defective accessory drawing to hard on the system. 

[Krlspokane12]

1 hour ago, Mopar1973Man said:

Grab a live data tool and monitor the TPS (APPS signal) and engine load. I wanna see if the something else is push the fueling command or is it just a poor quality APPS sensor. 

 

 

 

 

This morning I opened the Quadzilla app on my phone and watched engine load and throttle position. Not sure if this is as accurate as a live data tool, but its all I had at the moment.  But of course it didn't surge this morning .  I will drive it again at lunch and see if it does anything.  This is such a PIA since it seems to be completely random.  Once I locate my multimeter that wandered off i will test the tap wire on the VP. I will check the Quadzilla ground once I get home.  If this turns out to be a bad APPS, it will be par for the course, I keep getting crap parts that are supposed to be good since I bought an Alliant APPS from Thoroughbred diesel. 

[wil440]

My truck sort off surged or you might call it bucked quite bad when I first fitted the quad always hard acceleration, just sort of jumped a lot till I backed off a little then it was fine, my thought it was the OD slipping

This was on lvl 4 or 5 of a tow tune for stock truck, got ~~ssed off babying it turned it up to 9 and all gone no longer jumps/bucks or surges cos it's always on lvl9 now

[Mopar1973Man]

2 hours ago, wil440 said:

My truck sort off surged or you might call it bucked quite bad when I first fitted the quad always hard acceleration

That excessive low end timing. That is about the only thing that causes the bucking issue in the low RPM's.

[Krlspokane12]

I have reset the APPS, I'm not sure if it did anything since i have not had the surging problem again since i posted this thread.  I will see if it happens again sometime again during this week.  I will still check the VP wire tap and perform the WT mod this weekend.  I hope this will solve my issue for good. 

[Mopar1973Man]

@Krlspokane12 gotta ask what axle gears are running?

[Tractorman]

His signature says 3.55's, but it looks like his tires are 35's.  Oh, oh...

 

- John

Edited February 2, 2022 by Tractorman

[Silverwolf2691]

His signature says 3.55s and 35s.. 

 

Computer freaking out on lock up?

 

Also friendly reminder that above lvl 3 on a quad, every level is a division of 100% wire tap. For instance, i have a total of 5 levels. Lvl 4 is 50% wire tap, lvl 5 is 100%. I did that so i didnt have to tap a billion times to get to full wire tap. Having the full 9 (10?) levels just means each level above 3 is only makes the additional percentages smaller..

[Max Tune]

5 minutes ago, Silverwolf2691 said:

His signature says 3.55s and 35s.. 

 

Computer freaking out on lock up?

 

Also friendly reminder that above lvl 3 on a quad, every level is a division of 100% wire tap. For instance, i have a total of 5 levels. Lvl 4 is 50% wire tap, lvl 5 is 100%. I did that so i didnt have to tap a billion times to get to full wire tap. Having the full 9 (10?) levels just means each level above 3 is only makes the additional percentages smaller..

Hmmm, more confusion, great.

I'm already bald so I guess the only thing left is my sanity, which is questionable at best. When I pull the trigger on a quad, it's gonna be interesting 🤔🤔🤔😳

[Mopar1973Man]

3.55 gears and 35 tires are going to be a problem being the final ratio is 3.21 to the ground. Optimal is 3.55 to 3.73 to the ground. Be ready for a fight with EGTs till you change the gears to 4.10 in both axles which would be 3.71 which work work much better.

 

I'm running 245s on 3.55 which is 3.69 final and capable of 28.04 MPG.

[wil440]

4 hours ago, Mopar1973Man said:

3.55 gears and 35 tires are going to be a problem being the final ratio is 3.21 to the ground. Optimal is 3.55 to 3.73 to the ground. Be ready for a fight with EGTs till you change the gears to 4.10 in both axles which would be 3.71 which work work much better.

 

I'm running 245s on 3.55 which is 3.69 final and capable of 28.04 MPG.

Sorry but I both agree and disagree

 

I agree as Dodge designed the truck to operate 3.55 and 35 tyres does cause some problems no doubt about that certainly with EGT's

 

BUT once that is realised, with a auto just lock out OD and EGT's drop like a stone to figures that are fine, trans then stays in lockup most of the time and you have a really nice high  OD when needed as in downhill

 

My truck.... engine and trans stock as far as I know, quad and mechanical LP, 315 tyres and 3.55's, quad on lvl9 of a tow tune and I tow most of the time.

I lock out OD and 2037rpm is 55mph, 2100rpm is just over 60mph EGT's never a problem, I would say in 3rd LU on our motorways my gearing is a little too low and I could go to a slightly bigger tyre, but I won't,  around town and on smaller roads my gearing is just right as even when not towing I still lock out OD a lot as my truck holds onto lockup to just below our town speed limit

 

All it means is I effectively loose LU for a lot of the time but I wouldn't tow in LU other than downhill anyway so no harm done there

 

More ways than one to end up at the same place 

[Silverwolf2691]

@Max Tune, until you get the quad in your hand and actually mess with it, all of this can be confusing lol. I think the best way to think of the level system is more like "how many times do you want to press a button to get full wire tap?"

 

@Mopar1973Man, IDK whether it is the EPA and their BS or if its the factory programming in general, but my 2019, unless I put it into tow/haul mode, wants to be in as high a damn gear as possible... I'm cruising at 35-40 mph in 6th and lock up.. RPMs are at like 900 or so.. and it doesn't always downshift certain corners so in order to get moving I have to nearly bury the throttle to get it to downshift. 20-25 mph gets locked into 4th and again it doesn't like to leave it if I need to accelerate.. 

 

68rfe gear ratios

1st 3.23:1

2nd 1.83:1

3rd 1.41:1

4th 1.00:1

5th 0.81:1

6th 0.62:1

 

I mostly brought this up to say I think the cruise efficiency rpms might have been lowered for the newer trucks.. granted apples to oranges though too.. My 2019 truck is factory 275-70r18 and 3.55 gears.. 65 mph I'm running only 1500-ish rpms.. to get to 2000 rpm is at or over 80 mph.. (i think its been a while since i paid attention to the rpms while on the highway (freeway? What ever is 65+mph lol)

 

 

[Mopar1973Man]

1 hour ago, Silverwolf2691 said:

I'm cruising at 35-40 mph in 6th and lock up.. RPMs are at like 900 or so.. and it doesn't always downshift certain corners so in order to get moving I have to nearly bury the throttle to get it to downshift. 20-25 mph gets locked into 4th and again it doesn't like to leave it if I need to accelerate..

 

I've seen several auto Cummins do this too but out here you let it use the top gear like yours it would be building mass EGT's because of the constant grades. Very inefficient to run that low out here because it would always have to be lugging climbing 1% to 2% grade. Thankfully most of the ranchers and such all have manuals it the retirees that have the Auto's for towing there RV's and toys. I just done 2 clutch job in this winter already on a 3rd gen and 4th gen. Autos, are not very common out here. You still find out the EGT's drop lower up near 2k RPMs vs letting it settle to the bottom like those do. All you need to do is watch the live data of Engine Load and the EGT's will tell you a bunch.

[Silverwolf2691]

Wish i had i choice of a manual when i got the 2019.. No option there..

[Krlspokane12]

I know the 3.55s are not the best for the 35" tires. My plan is to eventually re-gear the truck once i have the funds to do so.  As of right now, i don't really have an issue with EGT's, i have a hard time getting it over 1250 at WOT.  I can say that the issue I'm having does not feel like a tranny problem, I can feel the truck speed up and then slow down.  It happens for a 2sec period of time but it is not consistent.  it will do it a few times and then stop and then it will happen again.  It also happens at varying speeds, sometimes accelerating from a stop light to cruising speeds.