Hey Folks,

I have a 2000 4runner - V6. It hesitates when I accelerate hard from idle, or even when I hit the gas while in park...seems like a throttle position sensor or MAF sensor....after the hesitation, the engine runs strong at all speeds. mileage is normal (19+) tune up (plugs, filter, oil) had no effect....haynes manual is useless of course

any ideas?

 

having the same problem 1999 5vzfe. Any suggestions out there?

 

clean your MAF. intermittent CEL will indicate this also. $5 can of MAF cleaner.

 

when was the last time you replaced the plugs, pcv valve, and done t- body cleaning, injector cleaning??? the list can go on...

 

That really is a waste of money. Gasoline is a very potent solvent by itself.

If there is something in the system that is not dissolved by gasoline, nothing else will dissolve it.

Injectors have small mesh screens that are there as a measure of last resort. Taking out the injectors and cleaning the screens or having them professionally cleaned is the way to go, if injectors are the problem.

 

o2 sensors....What the mileage, auto or manual,.....MK is right the list can go on. Have you pulled the plugs to read them?.....we need more data

 

Dude tell me you didnt use Bosch platnum plugs...?

TO be sure, use Only NGKs and Denso Duel electrode plugs....also it could be spark plug cables?

 

no injector cleaning as in a gas additive like seafoam or even better, techron in a bottle... also a good top end cleaner works very well via a vacuum line like the GM top end cleaner. works far better than seafoam........... btw if you use the cheapo gas then you need to do this de-carbon stuff more often. the deposits those leave behind is crazy. you should be able to google the difference in cheapo fuel and lets say shell 87. over time its a big difference. i no longer use cheapo fuel if i can help it

 

I would rule out a tps problem if its a hard accel,tps usually wear out contacts at just "off idle" position(i guess anything is possible though)....could be a MAF,also I would double check your intake tube hoses..on a hard accel,motor torques over on mounts,could make a crack/loose connection worse..allowing unmetered air into engine,causing lean condition...also clean the MAF and inspect its o-ring,make sure its seated and sealing...

another shot in the dark,double check the crank pulley bolt,if it gets loose enough could throw off RPM signal under hard accel.

I am also in the camp of,fuel cleaners,top engine cleaners,additives,ect are a waste of $$,actually I have never seen a toyota fuel filter cause problems,meaning all that was replaced was a filter and vehical is fixed...I know they look awefull after a million miles cut open...but I have never seen it so clogged that it dropped enough fuel pressure to cause any problems.....Same goes with fuel injectors,the solinoid either goes electrically open,or so weak they cannot open the needle valve,They also start getting noisey at this point,electrically is causing this not a partially clogged injector screen,,,when they go bad they do not work perfectly and have a clogged screen,it dosent happen on Toyota's ...Big three,yes it does...

clogged injector,fuel filter..big three yes,the crappy componants on those vehicals..Toyota's nope,not gonna happen.........fuel pumps the same...toyota's almost never go out,leaving you stranded...If you own a chevy,better have a spare in the trunk.