Ignition coil problems or torque converter ?

Hi all- new here. My second tacoma truck now beginning to have issues. 2002 prerunner, 2wd- mosty florida highway driving. 170k mi.

Symptoms:
When acceerating/foot on gas, noticing a 'shuddering' from front end. But this only happens at certain moments when moving steadily. Not happening from stopped position and accelerating. Mainly happens when already moving and accelerating through 45/50 mph uphill or incline. Once get up to higher speeds /or higher rpms symptoms smooth out or go away.

When slow back down to just around 50mph, and then accelerate again, the shuddering will happen again.

Shuddering is non existent or hardly happening when accelerating at same speeds (45/50mph) on flat roads.

With easier/gentler acceleration on gas pedal i can get through 45/50mph without any shuddering happening.

No check engine light. Nothing leaking. Fluid (trans/oil) levels ok.

Tried reinstalling all same sparkplugs and all same ignition coils. Then drove around for a day and symptoms significanty went away. Truck drove smoother for 2 days. Now shuddering symptoms coming back.

Considering just replacing all plugs and and ignition coils. But fear it is torque converter or transm. Have tow package but dont tow anything often, only tow small loads when i do.

Would love advice. Not ready to let go of 2nd truck!

 

Well, even though it appears to be coming from the front end, I would also check the drive-shaft. When was the last time the u-joints were properly lubed ? Do you also have a double-cardan type on your pre-runner. Lube that, as well.

EDIT: could also be motor mounts

 

I had a random shuttering / hesitation problem similar to yours. I noticed you checked plugs and coils. Did you try changing spark plug wires? My truck had 158,000 miles on it, still using factory wires. I recently changed the plugs less than 3,000 miles prior. Swapped in a new set of oem toyota spark plugs wires, hesitation problems gone.

 

Have not tried that thanks. Will do. I just took truck on long highway trip. All ok, except for the occasional shuddering that is still consistent with everything i described before. Its not getting worse. Its an auto transm, and the gears all feel like they are shifting properly. Tried the torque converter test (rev engine, press brake while moving through each gear to listen for telltale signs of torque conv problem)- did not noice telltale signs.

 

Just put full tank premium in tank. Engine seems tonrun smoother. I can still make symptom occur but its a little less severe. Fue injector?

Still no check engine light!

Obviously im still putting around - and my transm hasnt exploded yet.

 

Sounds like you need to break the problem down a little
Tune up , throttle body cleaning etc
When was last transmission service ?
https://www.tacomaworld.com/threads...sions-write-up-your-4-speed-automatic.325531/