2005 Tacoma Acceleration Issues

[SouthernVelo]

2005 Tacoma v6 4.0L 4x4 6spd Man.
87,500 miles
Original owner
Check Engine Light Has Never Turned On

Over the last 6,000 miles I have detected an increase in occurance as well as severity of the following issue.

When I accelerate from a stopped position my truck maintains smooth acceleration until it reaches approx 2500-2800 rpms. At this point it feels like the engine skips or kinda misses. Immediately after the skip my truck continues accelerating where it had just left off. This issue will happen about 1-2 times for each gear until I'm cruising at highway speeds. While cruising I do not feel any hesitation in the engine until I depress the accelerator to pass someone or my truck goes uphill. When I accelerate at highway speeds my truck then feels like it enters a lurching rhythm where it accelerates then skips then accelerates and skips over and over again.

Shortly after I first detected this I changed the plugs (Toyota stock), cleaned the airmass sensor and replaced the timing belt. I also disconnected the battery which is supposed to reset the computer, but I'm not too sure that simply disconnecting the battery actually resets the computer. After doing this minor maintenance the problem did not go away.

I have since taken my truck to a Toyota dealership, but they couldn't even detect it. I have also taken it to an independent Toyota repair shop who couldn't detect it until I made them jump in the passenger seat and ride with me. After he detected it he basically said it "felt" like a clogged fuel filter/bad fuel pump, but had never experienced this exact problem in a truck like mine before.

This weekend I plan to remove and clean the throttle body and check the plugs again.

Does anyone have experience with a problem like this? If so, i'd appreciate any information you have to offer.


Throttle Position Sensor
Speed Sensor
Fuel Pressure
Ignition Timing
Accelerator Pump
Air Flow Sensor

[lelandstanford]

Originally Posted by SouthernVelo

Shortly after I first detected this I changed the plugs (Toyota stock), cleaned the airmass sensor and replaced the timing belt....

You replace the timing chain?

I would start with the fuel filter first and double dose the injector cleaner.

[SouthernVelo]

No, I mean fan belt.

I'll juice her up with cleaner when I get a chance to work on her this weekend. I have a strong feeling that the cleaner will have no impact on the problem. I have run multiple bottles through this vehicle in the past w/o any positive results.

[Super Werty]

it could be the fuel pump

The problem is that the entire pump and filter is one in tank unit and it costs several hundred dollars from Toyota. Your best bet is to buy the Walbro 255 pump kit from URD. This allows you to keep the filter outside the tank which means changing the filter takes 5 minutes and $10, instead of a trip to the dealer and $500+. All of the boosted trucks are installing them with great results.

You aren't the first person to have a failed pump either.

Underdog Racing Development

[newsprint25]

I've got a 2.7L 4 cyl. that had an acceleration problem. I just finished replacing the PCV valve this morning, and cleaning the throttle plate and body. Seems like these drive-by-wire systems don't do too well if there is the slightest amount of dirt in the TB. So far, so good. Doesn't seem like a $6 part (PCV) should make that big of a difference, but idle is smoother, and I swear there is restored power. Last week I ran a can of BG 44k+ through the tank, seemed to help a bit, but the PCV replacement and TB cleaning did more.
BTW, which plugs did you use, the OEM Denso Iridiums? I replaced mine with the Denso Plats and so far, so good. With a V6 might be worth the extra $ on the Iridiums. I've also cleaned the MAF sensor. Resetting the computer is done by disconnecting the battery terminal. BUT, after you reconnect the cable, you should let it idle and bring it back up to operating temp, and then turn it off. Don't hit the throttle until after you turn it back on. This will allow the engine management system to re-map your air/fuel ratio. Good luck, let us know if you get the prob resolved!