Hesitation when hard accelerating on a 2006 Tacoma

I've got a 2006 Tacoma Double Cab, it's a 4WD and has a 4.0L motor and 160k miles. I've taken really good care of it, oil changed on time every time, changed spark plugs, has a K&N air filter. I recently changed Bank 1 Sensor 2 and Bank 2 Sensor 1 when I a got a check engine code. My problem is, within the last couple of months I've noticed that when I accelerate hard (when passing someone or entering the interstate), the motor is hesitating like it's not getting gas. I haven't gotten a single code for anything. No check engine light which would be helpful. I just changed the Mass Airflow Sensor and reset the computer (unplugged the positive battery terminal for 30 minutes) and I'm still having the exact same problem. Any help would be greatly appreciated!

 

Sometimes when I floor it on th freeway it takes a couple seconds to really get going.

I have a 2014 sport.

 

No it's hesitation in between getting gas and accelerating. Not when I first floor it.

 

Checked your fuel pressure? I also have a 4.0, but I have not looked at the fuel rail. Most have a pressure regulator that often has a vacuum line so that when vacuum drops, pressure goes up. I'd start there. It sounds like fuel starvation, and there is not much in the way, regulator and fuel pump, and a fuel filter perhaps... Any restriction and it might try to bog on acceleration.

 

No, but that was my next step after reading some on here and researching on the web. It's noticeable enough to drive me crazy. I'm going to fill up this afternoon and add some Sea Foam and see if that makes any difference. I'm sure it will be temporary at best but it'll narrow things down a little bit more for me. Any other thoughts or suggestions would be really appreciated! And thanks RobertHyatt

 

Check the spark plugs are tight?

 

No, but I will this afternoon. I just read another thread where the guy was having a similar problem and he said it turned out to be the spark plugs. I've got 160k miles so I'm hoping its nothing to do with the fuel system but I'm starting to lean that way. Really don't want to have to drop the fuel tank.

 

I know 30k for plugs but if you've got 15k plus I'd just change them out but knowing if they're tight is a good place to start.

 

Ok. Yeah, thinking back on it, it's been about two years and around 15k miles since I've changed them. I'll try that next and see what it does. If the spark plugs were misfiring or no good, wouldn't a check engine code come up Steves104x4?

 

Not necessarily. Check if they're tight first but I'd still replace them. In fact, I'd tighten them and put Lucas oil in the gas for a half tank (a week to clean out the chambers) then change the plugs. Then change the oil. Start replacing dried or brittle vacuum hoses.

 

Ok, so I put new plugs in this past Saturday, 10/3 and although i can notice that it's more tuned in, it's still doing the same thing in the middle of acceleration. So I'm pretty sure RobertHyatt is on to something and it's something to do with the fuel system. (Maybe the pump?)

 

Pumps can cause various problems as they die. We fought a series of "bank 1 lean" or "bank 2 lean" on a Thunderbird my son used to own. Never noticed any drivability issues, and it would light the tires on takeoff (4.6 auto). But we kept getting those here and there. A fuel pressure check told the tale however. It was about 20psig or so low. New fuel pump and that problem was gone. My dad had an early 70's Toyota pickup (22r engine). Ran forever, but at one point it started to driving a bit odd, hesitation here and there. But it got worse to the point that we replaced the pump and back to normal. Some fail by dying and you are stuck. Some fail by misbehaving and they can be a pain (as can ANY intermittent problem).. Best fix is always to take them to a shop, where they will almost never act up.

 

White TacomaTRD. Did you ever fix the problem. My 05 with 160k is doing the same thing. Slow normal take offs are fine. Heavy takes it hesitates. And hard throttle is not as bad. I cleaned the mass air valve and the throttle body. Also replace the spark plugs. Still the same.

 

That was in sep of 2015

 

I know. Still need to see if it was fixed

 

The Original poster last posted in 2021. Maybe try and send him a message? Some members get email alerts.

 

Will do. Thanks

 

I’m still learning on how to figure out how to navigate here

 

if the plugs are worn that badly, it would probably have a misfire code. (someone with more electrical experience can probably correct me on this).
shouldn't hurt to check them

the fuel filter is mounted to the fuel pump assembly in the tank and is not very robust.
put a bottle of seafoam in 1/2 gas tank and cross your fingers

when was the last time you removed your entire air intake assembly?
the breathing system does spit oil into the clean side of the airbox.
the charcoal airfilter does get clogged up eventually.

the throttle body probably has some buildup of gunk as well

spraying cleaner wont fix 160k mi of gunk in the intake system. it might need to come off of the engine and get scrubbed out.
get a new airbox gasket, if you do this.

you have an automatic tranny? I assume you know if it is not the tranny causing hesitation?

I don't think these trucks have a code for low fuel flow. (someone else can check me on this)

crud in the intake and throttle body will not necessarily give any air flow code, but can make airflow swirl around funny and cause weird issues.

good luck

 

Spark plugs are less than 10,000 miles on it. That’s the first thing I placed when it started happening. I just cleaned The mass airflow valve and that got the idling better. Also clean the throttlebody all within the last two weeks. I also put some in stuff in the gas tank two weeks ago in the last oil change. Still not noticing a difference.