We recently purchased a '91 4runner v6. All was fine for about two weeks until one day it would start bucking at normal driving speed out of the blue.

I called the toyota dealer and they looked at it . They said one of the coolant hoses was leaking which caused a vapour lock in the coolant system ? The cooling system was flushed and a new thermostat installed. My wife picks the truck up and i still bucks out of the blue, she takes it back to the dealer and the parts guy takes it for a drive with her. She said he was driving it more aggressively then she does and noting happened! He told her there might still be some air bubbles that are causing it.


I'm not to sure what to do next?? All the basics have been replaced with toyota oem parts: plugs, wires, cap and rotor aswell as the air filter.

Could it be the fuel filter??

It's a nice truck, but we have spent more on this 4runner in 3 weeks then our previous 4runner that we had for 3 years.

Dan

 

Try a search on here for "bucking" and input my name as the poster.
Look at the first & 3rd results.
https://www.yotatech.com/search.php?...der=descending

It sounds a lot like fouled injectors to me.
But it may not be, but it's worth a shot.