2022 Ram 1500 Rough start up

[Camren]

Has anyone experienced a "rough start". The best way I can explain this is, my truck spits and sputters as if it's not getting enough fuel like when yiu first try to start a lawn mower after you've run it out of gas. This only happens on the first start of the day, doesn't matter if it's 0500 or 2pm. After that every start is smooth. I want to say it's an injector or fuel pump, but I would think it would continue to start rough all the time.

The truck hasn't thrown a code of any sort, I've filled up at different gas stations thinking maybe I got bad gas, and there is no performance issues. Any ideas or thoughts would be helpful.

 

[Sabibb95]

Same here. Exactly as described. 22 Laramie GT 25k miles.

 

[Camren]

I only put 89 octane in mine. I did use an injector cleaner and it seemed to help, once I get it in the shop, I'll follow up with what they found.

 

[BenchTest]

Did some reading. Sounds like there are two constant themes with people experiencing this. There is a PCM flash that was made to address this issue. Another approach was a TPS reset (throttle position sensor). Another person says his fix was getting away from low octane fuel. I don't agree that low octane fuel would cause the issue unless is was low quality, low octane fuel. These engines should adjust themselves "up or down" for octane, performing better on higher octane as a result, but not causing idle issues on lower octane. Attached a screen shot of the described TPS reset.

 

[BenchTest]

As another reference. Not sure if it relates, but can't hurt.

 

[Camren]

Thanks for the info!! I'll try to reset the TPS and see if that does anything and reply with results. As the truck is still under warranty it's going in to have then run diagnostics. When it says poor fuel quality, is it referring to the Octane (87 vs 89) or more in line of where the gas station sources thier fuel (shell vs Exon)?

 

[BenchTest]

Thanks for the info!! I'll try to reset the TPS and see if that does anything and reply with results. As the truck is still under warranty it's going in to have then run diagnostics. When it says poor fuel quality, is it referring to the Octane (87 vs 89) or more in line of where the gas station sources thier fuel (shell vs Exon)?

In this discussion "low quality" fuel would be a source issue. Your truck should adjust it's timing and air/fuel mix automatically to compensate for 87 vs. 89 octane. If you had poor quality 87 or poor quality 89, then that'd be a separate issue that your truck couldn't compensate for.

 

[Camren]

Ok, turns out it is a bad fuel pump. There is a small check valve on the pump that isn't closing completely and is allowing air to seep in when it sits overnight, causing the rough start on the first start of the day. Mechanic told me to place the ignition to the run position and wait 15-20 seconds before starting to allow the pump to prime a little bit and push the air out. The pump is on backorder for the next 2-3 weeks, so this is the interim fix until I can get it swapped out.

 

[stevenP]

That makes sense, on the pump diagnosis. Wow that long of a back order, thats pretty bad.