Really need help hestitaing and stumbling!
 

Ok so my truck has a prob were its hesitating under acceleration. I've tired so much stuff to get it to quit but to no avial. It idles great but just under acc it stumbles and hesitates. Does not miss at idle or constant speed just under acc. I know its not timing or tune-up related. Please give me some ideas. As far as i've trouble shot i'm 90% sure its not a vac leak. Please help i have a 400 mile trip on sun that i "have" to drive for so thanks!

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What troubleshooting steps have you taken so far?

this must be the month of rough idles and hesitation for the 22re.

I've check plugs, wires dis cap and button. All of them good and less than a year old. It only started 2 days ago. Before that it ran like a champ. New coil. New oil and filter. Fuel filter and pump are less than a year old. Not slipping clutch cause does it if its in neutral with revving. not a headgasket. Checked for vac leaks by eye and ear. Found none and am sure there is not one. Changed o2 sensor. Tired resting comp few times. I seafoamed it about 2 weeks ago i'm not sure if i did it right but yea. Timing is good "i belive."

Idles perfect and has only been 2 days of hesitation.

Does it hesitate/stumble just under load?
Throwing any codes?
Have you checked the TPS, ECT sensor and VAF per FSM specs?

It hesitates/stumbles when taking off in 1st going through 2nd and after that it kinda stops. It does do it if i get out and its idling and i rev it up to like 2k or 3k rpm it will steadly miss. no codes. have not checked sensors.

Pull off the sensors one at a time to see if they make a difference. You might also pull each plug wire one at a time at idle and see if any cylinders are dead. Kinda sounds like un-metered air issue or fuel starvation. Runs fine at idle, but crapping as you raise the RPMS, right?

yea crappy upon increasing rpms but idles like a kitten. theres no dead cyls already checked.

My bets are on a clogged fuel filter (fuel starvation), a bad/misaligned TPS, bad coolant temp sensor or bad VAF. Test the TPS, VAF and ECT per FSM. Alternatively, you can uplug each and see if it runs differently.

Well fuel filters are not much so i'm going to get a new one tomarrow and see if its any dif if not i'll try the sensors with a multimeter.

UPDATE! I went just know to try messin with the gas cap. So as you all know it srumbled upon accel. So i took the gas cap "OFF" to see how it would do. The hes/stumbling went away. I thought it might only do it when warm so i drove it around like 20mins no stumble. So i was like alright. So i the tank was like half full with gas so i went to the station to top it off to full and also put gas cap back on. Got alil down the road and it was hes/stumbling alilttle but not much but still some. So i took the gas cap back off and drove it around for about 20 more mins and theres no stumbling or hes!!!!! whats the deal with that? is this a fuel pressure prob or defective cap? There is no fuel leaks so.... i'm stumbed cause its kinda supose to have a cap on at all times...i mean yea....ANYONE!!!?!?!?

well if the tank can't vent , then that will cause a problem. fuel cap , charchol canister.

well how does the tank vent? does it do it though cap? i was told canisters rarely have to be messed with....

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vacume in tank: check valve in the fuel cap allows atmosphere in. pressure in tank: cannister gets loaded with fuel vapor. throttle valve opens past p port: vapors are drawn into the intake. cannister or p port on throttle body clogged: pressured vapor can't go anywhere. the vented fuel cap kinda keeps things in check so theres allways a little bit of pressure loading the cannister.

i have a hesitation problem with my 22re as well. when i fill up the tank and run it just past a quarter tank, i remove the cap and it has a TON of suction.....what dose this mean? Kiroshu, does yours do this as well. what can i check or do to fix this?

Update! Today i replaced the fuel filter and changed oil. Also i tired buying a new gas cap to see if it would fix it. Well when i removed my old cap and drove with not gas cap 90% of the hesitayion problem stopped. Drove down the road somemore put cap back on it started stumbling bad. Took it back off and 90% of it went away but there was still some that was not there before. So i bought a new gas cap and put it on. It still stumbled and hesitated. took the new one off. 90% of the prob went away. So i thought well maybe i got a bad new one. So i went back to a diff parts store and go another new one and put it on. started stumbling and hestiating. took it off 90% of the prob went away. Now i'm quiet sure now its something relating to fuel and or fuel pressre Evap and all that. I'm not sure what to do next. I don't know if its a combo of fuel and something else oe what.....HELP!

can the cannister go bad? if so can you buy then at parts stores? where is that port that can get clogged? i would like to see if its cleanable.