Misfire #1 good performance when start, but rough when is warm

[svgarza]

Hi everyone,

im new on this forum great community btw, i just got a 2009 laramie 5.7 im from mexico and since the truck is built in USA it should be ok to ask for help here.

well here are the symptoms, first time in the morning when i start the engine everything is fine it looks fine on idle but when the engine is hot it start to act weird like if im going slow and try to push the gas pedal like moderately it feels like the engine doesnt respond as it should like lots of hesitation on acceleration.

note if i turn off the engine and start it again start normal even if is hot then first moderate acceleration runs fine but when i stop and try to accelerate thats where the rough running begins also if i stop rough idle is present

i ordered the coils i got a great deal $17 each oem and also ordered the spark plugs i did this because i just got this truck and i always do a full tune up even if doesnt need it i like to know when i changed any part or anything else.

other thing it comes to my mind are the lifters and maybe cam i hope i dont need to go that route but well this is very common too

what do you guys think?

thanks

 

[Kotta390]

Hi everyone,

im new on this forum great community btw, i just got a 2009 laramie 5.7 im from mexico and since the truck is built in USA it should be ok to ask for help here.

well here are the symptoms, first time in the morning when i start the engine everything is fine it looks fine on idle but when the engine is hot it start to act weird like if im going slow and try to push the gas pedal like moderately it feels like the engine doesnt respond as it should like lots of hesitation on acceleration.

note if i turn off the engine and start it again start normal even if is hot then first moderate acceleration runs fine but when i stop and try to accelerate thats where the rough running begins also if i stop rough idle is present

i ordered the coils i got a great deal $17 each oem and also ordered the spark plugs i did this because i just got this truck and i always do a full tune up even if doesnt need it i like to know when i changed any part or anything else.

other thing it comes to my mind are the lifters and maybe cam i hope i dont need to go that route but well this is very common too

what do you guys think?

thanks

News to me about lifters and cam having issues in this engine?? I know the lifters can bleed down and cause a tick on first start up but I have only ever heard of one or two where a lifter has collapsed completely. What you are referring to is not a mechanical moving part like you describe. If it was, it would be doing it all the time. Do you have a check engine light on? Normally if your problems were happening in the morning and clear up after it warms up, I would suggest running a fuel system cleaner through the fuel rails.

Since it warms up and starts to have a rough idle and run poorly when you start to accelerate, I would look into your fuel pressure and see if your fuel pump isn't starting to take a crap on you?

 

[svgarza]

yeah check engine is on, forgot to mention that, cleared the check engine when a guy told me it was a misfire in the #1 then it came back on after the first moderate acceleration.

other thing for example i can start the engine let it warm up until it normal temperature and idle is perfect, problem with rough running and rough idle start after i push the gas pedal like when trying to overtake, after that truck acts really weird, if i turn it off and start it again, everything seems to be back to normal until moderate acceleration.

will take a look at the fuel pressure and pump

i knew i was going to spend some extra bucks on this truck when i bought it, because it was parked for like 7 months, but i bought it for half of the market price here in mexico so i have a good margin