Engine Hesitation

I have tried searching around here for similar problems but come up empty handed.

So here's the problem. I have a 2004 3.4l and when I accellerate quickly the engine hiccups and then it accellerates normally. Seems like most of the time when this happens the engine isn't cold but not yet warmed up yet either. According to my SGII its about 120 degrees. Something like this happened before but happened all the time it ended up being a plug wire so I replaced the wires and plugs in april 2010.

Any ideas on what to check.

All help greatly appreciated.

Thanks in advance.

 

eventhough i have the '01 2.7L and mine did this for a while and i seafoamed the motor, changed plugs, changed oil and cleaned throttle body and Mass air flow sensor which cleaned up the hesitaton, idle and gave the motor an overall "healty" feeling....i think the you will see your fix if you do the seafoam and throttle body cleaning since your plugs and wires are relatively new

 

my 97 3.4 does it when it is cold, it's caused when the engine rpms are up'ed before it gets up to running temp. it's been doin it for 10 years and has never tripped an engine code. It's like there is an automatic choke on the engine that stays on too long, except my yoder aint got a choke..... sorry I don't have a fix for you

 

tps maybe? looking into that (throttle positioning sensor) if above mentioned things dont work first. also check for air leaks in all your hoses and vaccum lines, and try re-seting the computer by pulling the efi fuse in the fuse box....and last but not least while your at seafoaming everything and spark plugs since you have the 3.4l change the fuel filter since its super easy to get too.

 

So far no luck after cleaning and checking the above mentioned ideas. Still hesitates when cold. After the engine is completely warmed up there's no signs of anything wrong. Any new ideas out there before I'm forced to go to the stealership.

Thanks again.

 

maf sensor

 

So after a lot of cleaning and poking around as a last resort I thought I would check my plug wires, I figured less than a year old no way could there be anything wrong with them.... turns out drivers side middle plug wire was all burnt on the outside of the boot. Which is really crazy because last April I replaced what I assumed to be the stock wires because all signs pointed that way and same exact plug wire was burnt then also. I had a hesitation in hard acceleration then also but the symptoms weren't exactly the same as this time so I thought there was something else to it. So I put a new set of plug wires on tonight and I will have to see if that clears up all the issues.

Does anyone have any idea what would cause that plug wire to arch like that and fry the boot twice with in a year?

Thanks again for all the help and suggestions, and any future help.

 

Well new plug wires seemed to fix it but it didn't. The problems I was having lessened but still there on occasion. Today while I was driving I pulled up to a stop sign and kinda rolled through it in 2nd gear went to accelerate and it sputtered and backfired in what sounded like the drivers side of the engine bay. Later in that same drive going up hill in third gear accelerating kinda hard and it stuttered let off and accelerated slower and all fine.

This is driving me nuts and I hate to have to take it to a dealership.

Any new ideas out there?

And as also thanks for the help.

 

Also, during idle and light acceleration no problems. I cant really see taking it to a dealership so that they can poke around try to get it to do it for them and change me an insane amount of labor for diagnosing most likely to come up empty handed. Also hate driving it like it is in case I am making it worse by continuing to drive it but I have no other choice

 

My 08 toyota tacoma hesitates going up a hill only. i changed the 02 sensor, MAF, replaced coil because i had a bad boot on it. changed sparked plugs. stumped....any thoughts?

 

Mine is doing the same thing after cleaning the throttle body and the MAF sensor when the engine is still cold (water temp less than 130).

Last week, I ran a can a seafoam through the tank and 1/3 bottle through the vacuum line.

My running water temperature is 175. Maybe it's too cool.

I plan on installing a new set of plugs tonight, so we'll see what happens.

 

After installing a new set of plugs, my truck is running a lot better. We'll see how it does in the morning from a cold start.

Old plugs: NGK BKR5EKB
New plugs:

$18 Denso K16TR11 Spark Plugs, Pack of 4

Denso K16TR11