Hey All

Not sure if i posted about this before as I've had this issue for some time now but it was very rarely it happened.

As of late, it has been happening more.

So here is what happens:

From a stop - i step on the gas (normal acceleration) and as i start to accelerate the rpms drop and go back up and drop, etc and acceleration is not smooth. almost feels like the car is choking or like it was running out of gas. almost seems like it would stall but it never stalls. it goes away after a few seconds and when at speed i never experience it. only when i'm starting from a stop.

Idling - When sitting in a parking lot idling this happens from time to time. the rpms bounce around from idle... almost like it is about to stall but it never does. it recovers.

i can never steadily recreate this issue from the stop to start point but i can probably get a video of it while in idle.

Dash is free of lights. No CEL. New OEM plugs put in a while ago in hopes it would fix it but it didnt. Seafoamed it to see if that would help, nope. injectors going bad?

anyone experience something like this?

03' 4R 4x4 V8 with 217k miles. Has always been rock solid with no issues. This is the first worrisome issue i've ever had with my 4r.

So, just fixed a lot so similar problem, my issue was plugs. But in the middle of all of this, I pulled the MAF and TB and cleaned it out. I also pulled my PCV and cleaned it too.

Have you tried any of that yet? Cleaning those three things is pretty simple and fairly quick.

CRC makes TB and MAF specific cleaner and it's pretty effective...you can find it at your local parts store.

Good luck!!


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I have an 04 V8 and know EXACTLY what you are experiencing. I checked my maintenance log and see that I replaced the plugs at 150K, I have 221K on them now. I've replaced the PVC about 20K miles ago and last week sea foamed the intake. I do have the CRC MAF spray, I will try that but I just thought it was just my truck that experienced it. Strange for sure.

Ok....So two things I have experienced with my 05' with very similar happenings to what you guys are experiencing. Most recent was, I had a tree key stuck in my mass air flow sensor...did some funky things to my truck and made it actually stop completely on the side of the road before I figured it out. Pretty simple fix....Give ur MAF a good cleaning if you havn't already......

2nd....Which is a little bit more of a problem....
When I first bought my 4R from the dealer,used. On my first test drive, everything seemed fine for the first bit. Then i noticed a bit of rough idling....Then when I went to give it some "good" acceleration(pedal to the floor almost) the truck would shutter and have a hard time accelerating.

Made the dealer look into it before I even considered purchasing it....

Turns out it was the FUEL FITLER....had them replaced it and never experienced any issues again....Could be the fuel filter but that seems kind of difficult to diagnose yourself.

Hope this helps

I did clean the MAF when i was replacing the plugs and seafomaing. I did not directly clean the TB as i hoped Seafoam would have taken care of that but i can check the TB and clean it directly.

I replaced the plugs to see if that would help. I used Denso iridium plugs. Haven't tried replacing the PCV valve yet but will look into that.

cleaned out my MAF while changing plugs. But i will double check to make sure nothing is obstructing the flow in the airbox. also i did read somewhere while googling that someone had acceleration issues (not the exact same) and the dealer told him to change out the MAF.

also, i thought it may be the fuel filter. i was thinking maybe it's clogged and is not allowing fuel to get thru very well. so i did some reading and i don't think you can change the fuel filters on a 4th gen 4runner. i remember reading that it is built IN the gas tank so service is near impossible... and actually it is built not to be serviced...? can anyone confirm?

thanks y'all!

Have a look at my TB before and afters at the thread below. I had also Sea Foamed this truck in the past, not sure it gets it all...

1st and 4th Cylinder misfire




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will do. im going to pull and clean the TB this weekend. Also going to order a new PCV valve.

thx!

Went up and found where it was ....mine is an 04 V8. This gives you a pretty good ideal where its located.

Attached Images

 

Pull out the ignition coils and look for cracked boots and inspect the coil in the boot ( don't pull it out just look at it). It seems odd that you aren't throwing any codes though. I have the and issue and I'm hoping it's only the ignition coils and not injectors or just low compression in the cylinders. Another thing to look for is vacuum leaks, those can cause shutter or as I call it hiccuping while accelerating.


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Maybe a stupid question--but would this be a schematic of the fuel tank?

i didnt inspect the coils in detail when i changed the plugs but i remembered overall they looked good. if the pcv valve change doesnt fix it and i cant find any vaccum leaks, ill check the coils next.

just changed my pcv valve and like other posts i've seen, pretty gummy but still rattles. lost the stupid foam insulator for the valve in the process. dropped it somewhere, maybe down the engine bay. LOL

that looks like its on top of the fuel tank? would i have to drop the fuel tank?

found the answer to my own questions. googled it and found some other posts of peeps talking about having to drop their tank. fun fun fun. :T

New pcv but still facing the same issue.

How can I check for vacuum leaks?

Anything else I could check before I drop the gas tanks to replace the fuel filter?

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Came across this while troubleshooting a problem on my moms truck. What was the end result? Did you have success after changing the filter? I realize this is a long dead thread but we’re experiencing similar issues with her 03 v8.