My dads 4runner just recently developed a problem that has been getting worse as time has progressed. I dont know much about the 3.0 as i do the 3.4L so ide like to thorw this out to you guys

At start up either cold or if its been sitting about 10+min after driving the truck starts fine but then idles really rough as if its about to die and the truck is shaking pritty badly. If you rev it up a bit it will eventualy go away i guess once it warms up a bit more. Then when your driving at part thorttle on a constant throttle position the truck starts to go faster then slower then faster (you can hear it in the engine)...there is a serious lack of power during this whole time. Thats until you punch it then truck just roars (for a little 3.0L roar ) and drives its normal slow self.
I figure that it could be a number of sensors, im looking at the o2 sensor as it never has been replaced and my 3.4L Taco did similar things when it was a dead o2, and the fact that at WOT it does not use the o2 sensor and at that point the truck runs great. Anyway let me know what you think, winter is here truck was just insured from 3mths sleep and is ready to be driven (by my dad)

THanks guys!

 

I's check your tps, if it sounds like it's hunting for the correct engine speed.
Try this link:
http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml

 

thanks for the tip ill look into that! Thanks for the link too.

 

Also check the timing and perhaps the throttle bodyinjectors need a good cleaning.

 

You call that a stumble? That's not a stumble! Try this one:

Driving along at light throttle, you think you've just hit the worst pothole of your life, only there's no deflection at the steering wheel. This doesn't happen with any consistency: sometimes it's within the first 5 minutes after starting, others you can go all day w/o it happening, or it'll happen after you've been on the road several hours. What you finally notice after several years of it happening [which, btw, it has done since you had 30k miles on the clock, and have complained about to Toyota, but after using your truck for parts deliveries for several days on multiple occasions, they only say "we can't get it to do that..." and give your truck back w/ several hundred more miles on the odo & no gas in the tank] is that the engine comes to a dead halt momentarily, the check engine light comes on, & then everything is running normally again, all within the space of .4082340970143 second.

Now, that's a stumble!

 

yep thats ewhast going on....but just recently the speedo completly died now and all the stumble went away!?????
now the O/D light flashes....and check engien light is on....ill get a code once i get that chance.....damn 3.0L's...

 

any codes?

 

speed sensor?

 

Yea im gonna check for codes tommorw as today i have alot of work to do, 100% of the chance it is the speed sensor that just took a nose dive. I just hope thats it, its just funny how it stumbled alot when the speed sensor was working 50% of the time, but then the stumble went away right when the speed sensor completl died.