2011 2.7l occasional backfire on startup??

I have an 08. I used to get the pop on cooler mornings after sitting for a wile. I think it is unburt fuel in the cat. I let mine sit and idle for a few seconds before shutting it off. Hasen't done it in 20k miles ever since. it fixed it for me.

I also have a K&N cold air intake. Did it before and after that was installed...

 

when my truck was completley stock, it backfired on startup. when i took out the stock filter, it still backfired. and when i took out the secondary filter, it backfired on startup. and then i put a new muffler on, and it backfires even louder now

most of the people i know with the 2TRs have this problem. seems normal i guess.

 

Mine does it sometimes as well. I could be wrong, but it seems to happen if I shut the truck down immediately upon parking vs waiting a few seconds for it to idle down. Especially if I had just had to rev it a bit to inch into a spot. Either way I doubt it is anything to worry about. Just seems like a bit of leftover fuel burning off.

 

Mine only does it when its been sitting out in the cold and on a slant that makes the nose of the truck lower than the rear

 

We've got two 09 2.7s at work. I drive one of them. It always runs perfect, but has the noise you describe as well. I've heard the other one start up and make the same sound. Both trucks have almost 50K on them with no drama. Just the nature of the beast I think. Sounds like crap but doesn't seem to be hurting anything.

 

I have a Tacoma 4 cylinder with 10,000 miles on it and it sometimes gives a very light pop on start up. It may seem to occur when it does not start immediately.
Has anyone spoken to the dealer

 

I had a dual sport bike that would do similiar things....until I rejetted to a richer mix.....all vehicles come from the factory as lean as they can make them(run)...EPA emission standards.

 

No backfire or other popping sound on cold start here.

 

same here my reg cab has about 8,000 miles and it does it sometimes. although its not very common nor something i believe i could reproduce for the dealer to check out or even for me to video.

 

i actually thought it was due to the muffler i had installed i have a flowmaster 40 and i know i lost a significant amount of back pressure doing so.

 

just bought the 2009 truck with 24k. So far I enjoy running around in it.

The backfire occurs on some cold starts and some afternoons as well leaving work.
I'm gonna try the idle for a few seconds before cutting the ignition off after pulling into work and see if it helps.

 

I've never noticed mine doing this. I removed my secondary filter 30k miles ago and I always let the truck idle for about 10 seconds before shutting it down.

 

I've got a 2010 with about 25k on it. Mine does it all the time, and I haven't had any issues with it. It actually sounds kinda badass.

 

Remember these are Taco's we are talking about, sure they will pass a bit of gas.

 

Mine does it also, and has the secondary air filter removed. It only does it when the day I park it is warm ( for here ) 70's-80 maybe, and it goes down into the low 30's at night,it will make some type of backfire at the exact time it fires up that morning. It never does it a second time either. I alway's blamed it on some part of the cold start enricher trying to compensate for the 50 degree temp. change from when I parked it till when I started it again. Also we just put new Denso's in it, and I don't remember it ever doing this with the original plugs,but my memory ain't all that good either.

 

My Tacoma 4cyl does this, too. Like a lot of others here it hasn't set a code or caused any real issues, just pisses me off because it isn't supposed to happen. I have tried to pay attention to when/where it happens and it is always after sitting for a period, usually overnight. The only connection I have made is that when it happens the fuel is sitting at less than half so not sure if there is a connection there.

 

Well I mentioned this issue in post 21 in 2011. I still get it during cold morning starts sometimes, but after 5 years there have been no ill effects that I am aware of.

It's not ideal, but it doesn't bother me anymore.

 

Same here, 2016 tacoma, on occasion, 1600 miles so far

 

My 2012 pops on cold start. Can't actually hurt anything as it's just unburned fuel leaving the engine while it's cranking. Then it's ignited through an open exhaust valve by the burning gases exiting the engine because the AIS is mixing air into exhaust header.


Greg

 

Both my 05 & 08 4 cly trucks have done this. Usually it occurs after startup when rolling in first gear right when you let off to shift to 2nd. Doesn't usually do it leaving from house in early a.m., just leaving from work in afternoon.