3,4 stumbling need a hand

[3rd gen Mattie]

Ok I know this has been covered but the 4 runner I bought for my mom has this stumble if you run the crap out of it it’s fine but say you are driving and come up to a hill and press the gas it will stumble a few times I can hear it in the exhaust at idle I tuned it up before driving it for the first time did the valve cover gaskets tube seals plugs cleaned the throttle body changed air & fuel filters changed the oil poured some sea foam in each plug hole down each runner of the intake and a full bottle in the gas tank let it soak for a few days she fired right up and is so quite u can’t hear it run . But I just don’t know what else to do it hasn’t thrown any codes it could be a clogged injector, junk from the tank clogging the pickup
Coil ,plug wire any input would be greatly appreciated

 

[Blitzkrieg]

To be clear - did this issue start after you did what you state above OR did you do what you stated to try to resolve the problem that was already occurring?

 

[spartacus]

Ok

i would also clean the maf and test it. check for vacuum leaks.replace the pcv valve. low cost but effective .Do you have access to obd -IIscan tool. if you do then you can look at stft and ltft and figure out if the engine is running lean or rich.what are your maf readings and o2 readings etc and will give you a better diagnostic picture.

 

[3rd gen Mattie]

To be clear - did this issue start after you did what you state above OR did you do what you stated to try to resolve the problem that was already occurring?

I just did that work before I even started it but didn’t notice the skip when I first started it

 

[jgue467]

...
plug wire any input would be greatly appreciated

If you haven't already put in a new set of plugs and wires, I'd do that next. Cleaning MAF as others suggested is also a good idea, lots of how to on here and youtube vids, careful - sensitive parts yet it can make a big difference.

Seafoam is good at cleaning out the fuel intake system yet like other products takes 2-3 tankfuls for a 'full' effect you can feel. So keep doing that some more.


Luck and enjoy that runner! :cowboy:

 

[97t4r81]

FUEL FILTER. Oem is best, but new beats old. Adjust throttle cables if they have lots of slack. Otherwise everyone’s suggestions are all relevant.

 

[3rd gen Mattie]

I have a extra maf and I hav the coils from mine so I’m gonna have a swap fest today I guess

 

[Ricktuk]

order one of the obdII blutooth readers from Amazon. gives a running diagnostic. The BAFX is the one I got. $21 bucks. It picked up a problem my Father in law was having in his Dakota. code was popping up and then clearing itself. but could be seen while it was running. Of course that was Chrysler electronics. but a great device at the price

 

[Chillnfixit28]

Hey if you turn the key to the on position but dont start the car, after everything primes and cuts off, open the hood and listen. Is there any noises? Any at all?

 

[TennesseeRed]

Maybe check the cat? if it's bad, it can run fine on level ground, but do just what you're describing on hills.

 

[3rd gen Mattie]

I drove it yesterday for about 4 hours & on the way back I noticed the ECT power was off so I turned it on and while it didn’t totally go away it drastically reduced the bucking I’m kind of with you on the cat you can hear the skip at the tail pipe . I don’t really feel like it’s a plug or coil maybe a wire at the most
But just going off experience I’m gonna say ether the cat or a potentially clogged
Boot on the fuel pickup

 

[3rd gen Mattie]

Hey if you turn the key to the on position but dont start the car, after everything primes and cuts off, open the hood and listen. Is there any noises? Any at all?

About the only audible noise it makes at all is that possessed fuel vent that makes the electrical buzz noise even when it didn’t have a battery in it ( that’s just f’n weird)