Backfire/ popping and hesitation on hard acceleration

I've been noticing that I have a popping /backfiring noise with hesitation when I accelerate hard on my 03 tundra 2x4. Any ideas on what it could be? 284,Xxx on the gem and if you let off it will go away but just have to slowly give it gas and it will run out till 80 or so but that's about it.

 

When were the timing belts changed?

 

It's scheduled to be done this Friday.

 

Have your ECM checked, tested

 

Did the timing belt cure the problem??

 

Check your MAF sensor and check for possible vacuum line leak or collapse.when you accelerate hard it pulls more vacuum.

 

Replaced MAF, will check vacuum lines,thanks, cheaper than replacing the ecm

 

PS bad gas mileage also all of a sudden

 

Went from 16 down to 9

 

This is a long shot but try running some seafoam through the brake booster vacuum line going back into the intake.start the engine ,pull off the vacuum line,while the engine is running pour half bottle into the line to the intake.go slowly because it will stall out the engine,when you have half bottle poured in,turn off the engine.be sure the truck is level as possible and outside.let the truck sit for 10 minutes.start engine. It may be hard to stats but it will.It will smoke out the tailpipe like it's on fire but don't worry. It's burmibbout build up in the intake and valves drive it for a few miles and it should clear up.You should notice smoother idle and better response. I use it in all my vehicles.Put the rest of the can on the gas tank.Good luck!

 

Had the timing belt replaced, runs stronger than it did but still has the popping on hard acceleration. The tech thinks it could be a broke or weak intake valve spring broke or slightly twisted causing it to not close completely. I have to replace the valve cover gaskets because they've been leaking and another tech said to push down on the valve and see if it's weaker than the other ones. Hopefully I can get it back to him and get it checked out next week. I have a misfire on the #4 cylinder, replaced the coil and no difference, still the popping on hard acceleration. If no evidence of a bad spring the other tech said to swap injectors around. Will post later on the diagnosis. The timing marks all lined up as well when he changed the t-belt Friday.

 

Chief 01, you're experiencing the same problem?
My mileage is still around 13.8 -14.4 so it's about the same, would be a little better than that but I run on about 75 ish in the morning heading to work.

 

Yep, it almost feels like it shuts off and runs rough until i leave up on the throttle,then it smooths out and at red light it idles at 500 and rough and other times it at 750 and smooth, check engine light keeps coming on

 

Not sure if timing belt was ever changed, scanner said something about ECM,

 

Have you disconnected the battery lately for any reason?

 

No, the first codes were for 02 sensors, replaced all,then it was saying miss fire,bou bou one new coil and moved it around, then MAF/VAC code,tryed cleaning it,kept coming up so replaced it.

 

Replaced all plugs also

 

Check the throttle body and see if it's corroded.
Mine was nasty, he cleaned it up with some cleaner and did a fuel injection cleaner and got my idle back up to 950 or so.

 

I did also and a fuel filter.

 

Did all that with seafoam 3 months ago when it first started acting up

 

That's before the new belt and water pump was replaced, belt had 140k on it but nothing other than worn and stretched is all I could see, no teeth missing.

 

Changing timing belt and water pump cam seals r out of my league

 

Sorry for taking so long to get back to ya, making boilo and ya know ya half to test it out, don't mean to get off topic, but it's driving me nuts and emptying my wallet

 

Boilo?

 

172,000 on my 01, bought used 4 yrs. ago, no problems expect front brakes, sounds like the norm from what I hear

 

Yes me too, I was fortunate to be able to watch as he tore it down and see that it was actually replaced with a new one, factory one at that. I hope it's a valve spring though and get it resolved. He's covered up this week but said to holler at him next week. My seals weren't leaking, he changed the left side one but the bolt on the right side was so tight that he was afraid of breaking it off and then it would be a major ordeal to fix that.

 

Yeah, have to keep that family tradition going,lol , 190 proof corn mash, honey and a few cinacinn sticks

 

Oh I see, sounds like you might have to pour a pint of that E90 in the tank with a 1/4 tank of gas and drive it like you stole it. Lol

 

I hear ya,lol, I remember reading that the ECM will cause these issues, somewhere on a different fourm I believe

 

You check you PCV Valve lately? Sounds small but they are important. Could be gunked. Its a vent for your engine that vents out of your drivers side valve cover and into your throttle body. You’ll need to clean the port of the PCV Valve too. I did mine when replacing the Valve Cover Gaskets.

My rpms are Steady Eddy after replacing the PCV Valve and cleaning the throttle body.