This is a repost from the newb section:
ok so here the deal. I think this started noticing this about a month ago. basically I have no power up hills. I mostly have noticed this in the morning on my way to work. as soon as I get on the high way my 90 4runner wont accelerate. Ill have the gas pushed half way down and the tac will sit at 2500 rpms and im going about 35 miles per hour, if I push it further it will rev to 3000rpm but instead of going faster it slow down, eventually after driving long enough it drives normally. I also noticed this is more of a problem when its cold or the engine is cold. what could be causing this? btw I recently had to replace the cat because it was stolen of my truck but i dont remember if this happened before or after i started having this problem
took it back to midas to check the cat. they said that was fine. the thought it might be the fuel dampener or the timing. when they did the tests they found nothing
any ideas. i have since taken it to my regular mechanic and they are having a hard time finding the problem.

 

tried pulling any codes?

 

I have/had a very similar problem. Mine is several things but one thing was that the trotlebody in my 22re was clogged with "black goo" and after cleaning it I got a lot better performance.

 

X's 2 on that.

Other very possible causes; TPS, O2 sencor; trying to pull codes may find one or both to be bad; if not, get a multimeter on them and check their resistance to see if it's within spec

 

Check the Fuel filter and fuel lines. The lack of acceleration, and specifically the 2500 rpm, hit gas, goes to 3k and has LESS power, sounds dead nuts on with how my truck acted when the fuel line burst.

The hot/cold, may or may not be related. If it is related, I would assume its since the cold start injector makes your truck use more fuel when cold.

 

its in the shop now. its been there since friday and I hope they find the problem tomorrow. if not i may need to junk it. which i dont want to do at all because i love that truck and I cant afford a new car.

 

they think it might be the tranny but it didnt feel that way to me. i should have it back in a few days and ill know exactly what they have looked at.

 

how hard is it to replace the fuel filter? would doing one of those fuel system clean outs the sell and the oil and lube places help?

 

when was the last time a proper tune up was done?

 

had wire cap and rotor changed at the begining of the summer

 

vacuum line

 

im not really familiar with the 90s model but i got a 01 tacoma and my mass air flow sensor went out and it ran good half throttle but died at full throttle but im not sure u even got a mass air

 

well, we hadn't got that far yet in troubleshooting, but it could be the air flow meter (we have a volume air flow meter- a flapper/door connected to a variable resistor that tells the ECU how much air is entering the engine based on how far that flapper moves and the temp of the air). Not quite as accurate as a MAF, but served its purpose well.

 

Well, he mentioned that the RPMs increase but the speed decreased. Im thinking there are tranny issues.

Let me guess, automatic? Hows the fluid look?

 

for the rpm's to increase without an increase in speed...:
... the transmission is slipping or for whatever reason is delaying a downshift...

... and that makes me wonder if the detent cable is adjusted properly (the cable from the throttle body to the trans).

So have we pulled codes yet?

 

dammit. The one time I skip to the end... Screw you Abe

 

what?

 

what is this "black goo" you speak of?
when i was cleaning the area before my tps i noticed there was some black sticky stuff, is this the black goo? And does it continue on past the tps farther into the throttle body?

 

yes, that is the black goo.
... the PCV system can deposit a LOT of residue within the intake system.

 

i have a 2000 toyota 4runner with a 2002 motor in it and i have been having problems with the idle and now i can't even move the truck it just sputters when i put into gear and try to accelerate. i have fixed the idle issue but i was driving to work this morning and it just start to sputter going up a hill and would not even accelerate at all. i had to limp back home at 5mph. i could barely touch the throttle and then it would cut back out. here is a list of what i have done to the truck to remedy some of the issues.

-clean mass airflow sensor and test
-clean throttle body
-clean idle air control valve
-new plugs and wires
-new fuel filter
-checked catalytic convertor and i can see light through it so i guess thats good
-i unplugged my o2 sensor on downstream and it didn't make a difference
-checked all fuses

i don't know what to do next i bought new oxygen sensors but i don't know if i need them or not i think i need the down stream one but the up stream one looked ok from the outside.

i am at wits end i am about ready to burn this truck to the ground so please help someone.