Taco has a hesitation!

My 02 Taco 3.4 kinda stumbles when the throttle is pressed, I can sometimes feel a slight hesitation. I have new plugs and air filter and have ran some injector cleaner thru a couple of times, it has 90k miles. Maybe the plug wires? Any help would be great!

 

I would guess wires next...

But the Fuel filter is a good choice too..

 

I'll guess here and say the fuel filter is a good thing to replace just like posted above. But I will also suggest cleaning the MAS too, and maybe the throttle body?

 

Good call! I will do the filter tomorow, where is it located? (02 tacoma prerunner quad cab) Whats the best way to clean the throttle body? Pull off the intake hose and spray it down with carb cleaner? When is a good time to change plug wires? Thanks!

 

I would try the filter first and then clean the Mass Air Flow Sensor second which is easy, then the throttle body last because it will be harder to do.

But if the filter change or the MAF cleaning does the trick, than you may not have to worry about cleaning the throttle body.

The filter I'm not sure, you may want to get a Hanes manual and that will help you out a lot. The spark plug wires I'm not sure for your truck, but I'll guess and say every 100,000 or 150,000 miles, maybe someone can chime in on that.

http://www.tacomaworld.com/forum/technical-chat/50153-how-cleaning-throttle-body.html

http://4runners.org/writeups/throttle/index.html

 

Will do, thanks for the help.

 

Thanks for the info on the filter location and the online manual.

 

Update: cleaned maf and tb, they looked pretty clean, had some black on the TB. Put new fuel filter in. Same issue, slight hesitation when letting off the gas and then gasing it again, can feel it more on slight inclines/hills when gasing, leting off and then re-gasing it kinda stumbles, not real bad but bothersome. The truck seems to be a little hard starting since day one, seems to turn over quite a bit before firing, Think I mite do plug wires, thats all thats left. I put a flowmaster 50 series on it with stock filter air box, could this do anything? Weird!

 

I got some new plugs to put in and went to instal but they looked brand new so I left them alone, air filter is new too. I am stumped! What is the best muffler to run? I am not very happy with the flow 50, kinda noisy for me.

 

Are you talking about stumble like when you are approaching a hill and you go to get on it and seems like it misses or something then after about a second or so it picks up and takes off?
Mines does this every once in awhile and I never really thought about it being a problem and it never bothered me cause it only happened randomly, but I can see that being annoying if it happened all the time!

Seems to me like it might just be a glitch in the computer software, but like I said mine only happens maybe twice a month.

 

Hmm, have you been getting worse gas mileage? I had a similar problem in my old 1997 Taco, turned out to be a o2 sensor. Also, a buddy just had the same kind of issue in his GT, same issue. o2 sensor. Replaced it and in both cases problem solved. I am not great with repairing autos, so take my advice with a grain of salt. But, it sure sounds like the same issue we both had. 90k is alot on the o2 sensor if I am not mistaken.

 

If it stumbles when you first press the accelerator, that could be the throttle position sensor. If it is either bad or even slightly mis-aligned the engine will stall a bit on initial acceleration.

 

Played with it today driving, it seems to miss a beat when you let off an re exelerate, like it skips a beat trying to downshift. How do you ajust the throttle position sensor?

 

88k miles, just did the timing belt.

 

Sounds like fuel pressure could be low as well. Maybe a sticky fuel pressure regulator?

Also, under what conditions does it stumble? When it's hot? When it's cold?

 

I am stumped, running out of things to replace! Is there a way to check ajustment of the throttle position cable? I feels like the kickdown is slow to react when letting off the throttle and then pushing back down on it. Like it hesitats before kicking down. Fuuuuuudge!!!!!!