hesitation/stumble/vibration

I own a 97 tacoma 4x4 with a 2.7 4 cylinder. My first problem is a
hesitation.this problem has gotten progressivley worse.while driving
at steady speeds or accelerating,can sometimes feel slight hesitation.
other times while driving at a constant speed engine feels like it dies
for a split second and then runs fine. I have installed new plugs,wires
fuel filter, fuel injection cleaner ,etc. happens with a full or near
empty tank.does not seem to matter if warm or cold, i would like to
clean the throttle body but toyota dealer says only a certain cleaner
will work???? I have let them have it for 2 days and they could not
duplicate, go fugure,$80 dollars later. my other problem is a driveline
vibration between 30-50 mph, and moaning noise,new u-joints
and tires did not make a difference. Any advise would greatly
be appretiated.i have no other ideas,(hope its not the rearend)
by the way ,it has 90000 miles.

Have you driven in water deep enough to enter the drive shaft(s)?
Have you recently driven off road (tires out of balance b/c of mud, lost weights, low pressure tire rotation etc.)?
The moaning is pretty normal for 4 wheel drives in general. It is most likely gear noise due to normal wear and tear. Double check that all of your gear lube levels are up to par and free of contaminants like water and such.

Have you driven in water deep enough to enter the drive shaft(s)?
Have you recently driven off road (tires out of balance b/c of mud, lost weights, low pressure tire rotation etc.)?
The moaning is pretty normal for 4 wheel drives in general. It is most likely gear noise due to normal wear and tear. Double check that all of your gear lube levels are up to par and free of contaminants like water and such.

I thought that maybe the wheels were off balance,this weekend
i rotated and balanced the tires,but still had the same vibration.
I havent driven in any deep water,my next step like you said is to
pull the diff cover and check for any contaminents.I have been
thinking of sending my rear driveshaft to a specialist to check
for balance.I work at a ford lincoln and mercury dealership(service
advisor) but none of my guys want to work on a toyota.
thank you for the advise. Im at a loss and dont want to spend
a fortune fixing this thing.

You won't spend a fortune and as for that diff cover, leave it alone! Only domestic trucks use diffs that you have to disassemble just to drain fluid. A toyota is simple, just pull the drain plug, clean the magnet, replace and fill until fluid runs out the fill hole! Too easy!!
That vibration almost has to be coming from the tires. The drive shaft would have to be wayyyy off or filled with water to cause a vibration that you could actually feel. My guess is poor balancing of the tires or uneven wear. If they are aggressive tread tires then some vibration is normal.

You won't spend a fortune and as for that diff cover, leave it alone! Only domestic trucks use diffs that you have to disassemble just to drain fluid. A toyota is simple, just pull the drain plug, clean the magnet, replace and fill until fluid runs out the fill hole! Too easy!!
That vibration almost has to be coming from the tires. The drive shaft would have to be wayyyy off or filled with water to cause a vibration that you could actually feel. My guess is poor balancing of the tires or uneven wear. If they are aggressive tread tires then some vibration is normal.


I had originally thought it was from the tires too. first i bought a
different brand of new tires and installed them,same vibration.
all season tires.then i swapped the tires and rims off my buddys
tacoma to see if it made a difference and it had the excact
vibration. his is as smooth as can be.the only other thing i can even
imagine it could be is the driveshaft.Im pulling it saturday and
shipping it out monday to be checked. ill keep you posted
on updates.thank you for info.

"while driving at steady speeds or accelerating,can sometimes feel slight hesitation, other times while driving at a constant speed engine feels like it dies
for a split second and then runs fine"------ had the same problem, tune up, new wires, and had the throttle body sensor replaced, runs nice and clean... good luck

"while driving at steady speeds or accelerating,can sometimes feel slight hesitation, other times while driving at a constant speed engine feels like it dies
for a split second and then runs fine"------ had the same problem, tune up, new wires, and had the throttle body sensor replaced, runs nice and clean... good luck


just wondering what you had involved for a tuneup? ive replaced the
plugs ,wires ,fuel filter and that was it...... I didnt know there
was a throttle body sensor., was it the mass air flow sensor.
I just talked with someone and they told me to pull the maf
sensor and clean it. I did this but it still does it. If you could give me
any more info on the sensor and what was involved in the tuneup
i would greatly appreciate it . thank you for the info

JC, that was all I did, plugs (What a pain) and wires. It was still not running right, so I dropped it by the dealership, got it back later that day, $27.00 for part, and $58.00 for labor. (Work order stated; replaced throttle body sensor), so I'm not sure, but it really runs fine now, almost sounds like a new one. I'm at 134,000 miles and counting. I drive between Washington DC and Virginia Beach twice a week, usually to Va Beach on Thursday and back to DC on Sunday, about 220 miles one way, so it doesn't take long to add up the miles. Good Luck

JC, that was all I did, plugs (What a pain) and wires. It was still not running right, so I dropped it by the dealership, got it back later that day, $27.00 for part, and $58.00 for labor. (Work order stated; replaced throttle body sensor), so I'm not sure, but it really runs fine now, almost sounds like a new one. I'm at 134,000 miles and counting. I drive between Washington DC and Virginia Beach twice a week, usually to Va Beach on Thursday and back to DC on Sunday, about 220 miles one way, so it doesn't take long to add up the miles. Good Luck


Im gonna call my local toyota dealership and ask them about the sensor.
when it was running bad was your check engine light on? mine has not
come on .thanks for info. Im wondering if they meant throttle position
sensor????Was there a part # on the repair order? I need help!!!!
this truck is driving me nuts!!

The receipt is in VA Beach, and I'm in DC, I'll look when I get home. The CEL never came on, just was really running rough, several times sounded like it was going to shut off it was idling soo bad. Keep me posted, and I'll get you the info on Saturday.

The receipt is in VA Beach, and I'm in DC, I'll look when I get home. The CEL never came on, just was really running rough, several times sounded like it was going to shut off it was idling soo bad. Keep me posted, and I'll get you the info on Saturday.


I finally figured this thing out!!!!!!!!!!!!!! i tested the ohms on the tps
sensor,they would gradually go up and all the sudden spike then \
go back to normal.went up and bought one at the toyota dealership
for $45 and put it on(about half and hour).this thing runs like a top
now with no hesitation.thanks guys for the info!!!!!!

p.s. now if i could figure out this vibration??????

jcl27 i to had/have that same problem. i have a 98 prerunner 2.7 that i bout from my bro. it was abused and has 175k miles. i had no power and it idle my teeth fall out. i raplaced coil packs, both o2's,cat,plugs wires,etc with no change. i then went to the intake, i removed the air muffler,vacuume box,put in k&n and opened the filter box. no change. next i put on a header, hooker muffler and 2.5 exaust pipe. great high end power. it is fast as sh** over 35 but know low end and the rough idle is still there. next i will replace the tps after hearing good things. as to the vibration check your wheel bearings. that is my problem. i think yours is a copleat assembly that has to be pressed in and out. a friend had his fail and it cost him 600 bills for one side due to the dammage it caused. good luck and if you or any one else has more info pass it on.

jcl27, I have a '96 4x4 tacoma with 115,000 miles that vibrates between 40 and 50 mph. It started vibrating around 85,000 miles. Since then, I replaced the rear U-joint, shocks all around, front brakes calipers and rotors. I had the drive shaft balanced and tried swapping tires and wheels with my brothers tacoma. Nothing helped the vibration.
My next step is to check the play in the splines on the drive shaft. It may not hurt to check yours. Let me know what you find out.

Have you checked the driveline mounts?