Ok well here goes. I have a 95 4runner. 3.0 6cyl put a rebuilt 3.0 in less than 10,000 miles ago. new with the motor was plugs, wires, cap, rotor, TPS, fuel dampener, and cleaned the intake. And after yesterday a new fuel filter. So just recently I have noticed that when I am driving and putting a load on the motor (accelerating or going up a hill) and the RPMS are anywhere around about 2700 or higher the motor starts to cut out/surge. As i said this is only happening like when i try to give it more gas to keep my speed up when going up a hill for instance. So i am curious as to what you guys think is causing this or if anyone is having the same issue. And what you think could be the problem. Any help/advise is appreciated.
Thanks

 

Im just throwing out some ideas. How many miles on the fuel pump ?, if its original it may be getting weak and not putting out enough presure under load. Check the timing, check for vacuum leaks. Is the TPS properly adjusted ?. the 02 sensor, if its original with a lot of miles on it, replace it. Buy a Denso 02 sensor, DO NOT use a Bosch 02 sensor, they don`t work well in a toyota engine.

Out of all of the things i suggested, i would replace the 02 sensor first. When the engine is at operating temperature the computer uses it to set the air fuel ratio, and if its bad it can cause the problems your having.

 

Thanks for the info. The TPS is adjusted to spec, timing is good, no vacuum leaks that i can find. The fuel pump is a good question as im not sure when it was replaced if ever. I am hearing alot about the 02 sensor and think i will start back up by replacing that. You said to use Denso? Any good info on where to get this at a good price. Or is it best to bite the bullet and go OEM from a toyota dealer?

 

Had a similar issue with my 22RE, ended up being the pick-up coil inside the distributer. FSM gives proper ohm readings. See my thread...

https://www.yotatech.com/forums/f116...lerate-234182/

Might check it out.

John

 

Well. New 02 sensor put in today. NO CHANGE still have the hesitation during acceleration around the 2500-3200 rpm area. Only does it if it is under a load, say up a hill or trying to gain speed in 3, 4, or 5 th gears. Will look into the pick up coil this week. Thanks

 

Ok so i think that I got this hesitation figured out. After many hours searching on here about this 3VZE engine i found that the NGK Vpower plugs are suppose to be gapped at .031 for this engine. New out of the package from Advanced Auto they seem to be gapped anywhere from .040 to .044. I put these plugs in when i put a new engine in about 8000 miles ago, never thought to check the gapping. So pulled the old plugs yesterday, and they were all covered in ash and corrosion!!!! All gapped at over .041. New plugs in gapped correctly at .031 and what do ya know NO MORE HESITATION!!! The good in all this is now i have a new fuel filter and O2 sensor that probably should have been done with the new engine. SO thanks for all the help and all the great info on this site.....
Will test it out in the hills this weekend.......

 

Updates are always appreciated. For future reference, you can test resistance with an ohmmeter on (almost) every electrical part out there, including 02s, to determine whether they're functioning, rather than buying a new one first.