Rough Start Up - Engine Sputtering Video

My 2nd gen did this about once a month. My 3rd gen did it just the other day.

Isn't there some kind of fuel system thing that runs when the truck is off?

 

Fuel Pressure Evap system makes a noise a couple of hours after you don't drive but its to balance out the air pressure in the tank. It really has nothing to do with a warm engine..

 

I ask because I'd go out in the garage and hear it running, then the next morning the truck would start like that.

 

I'll record my "cold start" after work. and when its warm.

 

Here's a good question, do you notice a difference in startup between an empty tank and a full tank?

 

No. But never really paid attention

 

If there is, its either the fuel pump or the high pressure fuel rail system.

 

I don't think so, I just filled up and it was happening before and after. Update: Dealership updated software and after couldn't recreate the stutter. I'm not sold on a software issue causing the problem but I guess I'll find out within the next day or so.

 

Definitely didn't fix it. Sounds just as bad now.

 

Woo hoo!

A problem I don't have!!

 

I would try going to a different Dealer, something is not right with that.

 

... yet.

 

Lol. He’s right. Thought I had a unicorn then 10k struck. Bewaaaaarrreeeee!!!!

 

This sounds EXACTLY like my 2nd gen...

 

Update #2 - Started reading post about engine sputtering and found some information on running higher octane fuel. I've run 93 octane since I bought the truck in Dec and really never had a problem. I'm lucky enough to have a job that pays for my gas and thought why not run the good stuff. From the link below, user GIG mentions his experience running premium and how it affected his start up. I went back to the dealership and spoke to the mechanic. I mentioned my octane to the mechanic in passing and he immediately mentioned this. He said that the 02 sensor was reading additional oxygen at first and was creating the sputter. Makes sense that it takes time for the issue to reoccur due to it needs time for the fuel to give off additional evaporates. I'll switch back to regular and update later.

 

Guaranteed, 100%, that will not solve this. This is the problem with internet conjecture....and your mechanic is using your theories to avoid troubleshooting the real problem.

 

Good chance you could be right... I didn’t mention anything but running premium though. Last thing I want is to keep going back if it continues. They monitored the fuel pressure while running and everything was steady. It would be pretty silly that a new vehicle would have issues just running premium in a hotter environment. What would make more sense if there was an issue with the mechanism that should bleed out that ‘extra’ pressure...

 

Given this is direct injection under tons of high pressure, I'd say that pressure probably is bleeding out over time either due to leaking pressure regulator, injectors, or a fuel pump is slow to prime. That delay in building back up the pressure is the slow crank, but once running the pressure would appear fine, so your mechanic is looking at the wrong thing.

Honestly, I'd request another tech on the job, or if you're not comfortable asking for that, take it to another dealership.

 

Thanks for the advice. My knowledge on these truck are limited so I appreciate the input. May try another dealership.

Edit- at new dealership now. Like Scooby mentioned, this mechanic doubts it has anything to do with fuel.

 

In my 2006 Taco, I was able to turn the key "on" and I think I could hear the fuel pump pressurize the system.
How about pushing button without foot on brake....wait a second or 2 and then start truck....
If that makes a difference, would that not point to slow fuel delivery...??

I am no mechanic, but this theory does make some sense to me..!