ROUGH starts on cold starts?

[HSKR R/T]

Unfor

unfortunately I see you have a tuner and 35's.

When I went in to have them rescan for 34's, they said no way. I said they had no issue rescanning my jeep to larger tires for free. They said, it's not a jeep, sorry. I asked about using a tuner and they said unlike a jeep which they allow mods and don't care (tire size, axle, etc) the ram is "locked". If you modify the coding they will deny warranty work. Even something as simple as tire size. So I had to swap tires back to stock. Even if you reload the stock oem computer, they can tell it's been changed, and void the warranty. Magnusson Moss act aside, they force you to sue them over the warranty.

Sounds like a crappy dealer for you. Would be worth your time to go to a different dealer. Even if it means driving an extra hour

 

[2020Larrie]

Well, it would be more like 4 hours, 2 there and then back.

Not to worry, I'm back in a JLU Rubi again. The mighty battleship Larramie is gone to the next person. Might be last post here, hope you all find the tsb helpful.

 

[stevea547]

Just got mine a week ago.. I'm in PA, have had a new Ram every year for a long time.. Day 2 remote start.. idle all over the place.. thought it was going to stall.. thought it was odd myself

 

[stevea547]

I've experienced very rough starts the last three mornings (at least) when heading to work.
I start the pickup using the remote start usually so it was possibly (see: probably) doing this before and I just didn't wasn't outside to notice it.
The truck acts like it doesn't want to start (but does) and the tachometer is all over the place all the way from near zero to 4K+ revving and nearly dying.
The truck sputters repeatedly and idles VERY rough with what i can only assume is non-standard noise coming from under the hood.
This usually lasts ~10 seconds before it seems to even out and has only been doing this on cold starts but I can't see this as being okay.
Anyone heard of other cases of this?

2019 - Ram - 1500 - Lonestar - 4x4 - 5.7 w/o e-torque - 3.21 gears - less than 2K miles -

I am having same issues. Been back to dealer twice and told they “Can not replicate “. Got worse with change of weather.

 

[MValdez]

I had this issue for over a month. Every morning, horrible rough start/idle. On 3 separate occasions my truck actually stalled out and I had to re-start it. I posted a thread as well and a member recommended i perform a throttle reset. So I gave it a shot and after performing the reset it actually worked. My truck starts up smooth and confident every morning. No rough idle at all.

How to perform Throttle Reset:

To reset the Dodge Ram throttle position sensor(TPS), You need to turn on the ignition without Your foot on the brake, so the engine doesn't start. Then press the accelerator on the floor for 15 seconds. Release the accelerator. Again, press the accelerator on the floor for 15 seconds. Release the accelerator. Then turn the car off and start the engine and drive.

 

[A-TEAM]

Well mine cleared up after that towing trip I had at 12k miles. Now I have 51k and it started rough starting again after towing a camper. Mine seems to happen when something drastically changes what the ecu is used to. Like daily driving for months then loading it up with gear and a 6k lb camper. I’m going to pull the battery cables for a half hour and reset all the computers. That seems to fix most weird ram problems I run into.

 

[A-TEAM]

Until morning…

 

[A-TEAM]

Unhook

 

[A-TEAM]

Also found this sensor was loose and out about 1/4”. Plugged it back in. S&b intake.

 

[A-TEAM]

Just put the battery cables back on and turned the ignition on for a minute then hit the start and it started absolutely perfect. I would try this before taking it to the dealer. All computers need a good power cycle/ reboot now and again.

 

[RamCares]

Just put the battery cables back on and turned the ignition on for a minute then hit the start and it started absolutely perfect. I would try this before taking it to the dealer. All computers need a good power cycle/ reboot now and again.

Hello,

We see that you were able to resolve this concern on your own. However, if this occurs again in the future or you run into additional concerns, please feel free to reach out to our team. We are available via private message.

Lex
Ram Cares

 

[theblet]

Sometimes putting the pedal to the floor a few times helps. Blow out some carbon plus it’s fun.

 

[A-TEAM]

Well its been starting perfect up until this morning, it happened again out of the blue, real rough start, didnt sound happy. It runs fine otherwise. Going to try turning the ignition on and letting the dash lights clear before starting it tomorrow morning and see if that helps.

 

[A-TEAM]

Sometimes putting the pedal to the floor a few times helps. Blow out some carbon plus it’s fun.

Ive done that too and it does indeed clear up right away. Its like the start is lean on fuel when it does the rough start.

 

[A-TEAM]

OK well I started it again this morning, but this time I turn the ignition on and let it sit until all the dash lights cleared, then started it, and it started perfect. It seems to do it when you just jump in hit the brake and start it immediately. Going to try this method for another couple mornings.

 

[Scram1500]

When you're starting the truck, do you leave your foot on the brake pedal? I've had mine run rough and stall if I take my foot off the brake when it first begins to crank.

 

[theblet]

OK well I started it again this morning, but this time I turn the ignition on and let it sit until all the dash lights cleared, then started it, and it started perfect. It seems to do it when you just jump in hit the brake and start it immediately. Going to try this method for another couple mornings.

Interesting. Maybe if you give it a couple seconds before cranking, it gives the fuel pump some time to prime up the fuel rails. The fuel pressure may be bleeding back into the tank when the truck sits for an extended period of time, hence leaning mixture on cold start. Not sure what mechanism keep the pressure while the trunk is off tho. (check valve?)

Curious to see your findings with this.

 

[uncc_99xj]

Interesting. Maybe if you give it a couple seconds before cranking, it gives the fuel pump some time to prime up the fuel rails. The fuel pressure may be bleeding back into the tank when the truck sits for an extended period of time, hence leaning mixture on cold start. Not sure what mechanism keep the pressure while the trunk is off tho. (check valve?)

Curious to see your findings with this.

This was my initial thought as well. There should be a check valve of some sort that keeps fuel in the lines so everything is ready to go once the pump energizes. I'd be willing to bet it's probably integral to the pump these days.

I have an old Cherokee that has a failed check valve (notorious on them). I replaced it once and it lasted 6 months before it went out again. The symptoms are long crank times, and often stumbling for a few seconds once it does fire until pressure builds up completely. After 18 years, I'm used to cycling the ignition 2-3 times on it to get around the rough starts.

I haven't looked, but I wonder if there's a valve on the fuel rail somewhere on the Hemi that you could connect a fuel pressure gauge to. If so, that would be where i'd start.

 

[theblet]

This was my initial thought as well. There should be a check valve of some sort that keeps fuel in the lines so everything is ready to go once the pump energizes. I'd be willing to bet it's probably integral to the pump these days.

I have an old Cherokee that has a failed check valve (notorious on them). I replaced it once and it lasted 6 months before it went out again. The symptoms are long crank times, and often stumbling for a few seconds once it does fire until pressure builds up completely. After 18 years, I'm used to cycling the ignition 2-3 times on it to get around the rough starts.

I haven't looked, but I wonder if there's a valve on the fuel rail somewhere on the Hemi that you could connect a fuel pressure gauge to. If so, that would be where i'd start.

That would definitely show whats happening if its fuel related. On older vehicles we would just put a "T" in line on the rubber hose. Prob not that easy on these.

 

[A-TEAM]

Just an update, ive been turning on the ignition and letting it sit until the dash lights clear , then starting it and its never rough started doing that. It’s almost like the tune needs a few second delay before cranking.