Def sounds like it could be the ignition coil pack. I had my ignition coil go bad on my 95 Jimmy (back in the day) and it ran similarly to the symptoms you are describing. It ran, but very poorly, idled really crappy and had no power. Luckily I was close to my house and made it back. It's a pretty cheap part and should be an easy replacement.

On a side note (and this may be way out in left field) but the real rough idle and poor driving performance also reminds me of a clogged/broken EGR valve. I'm not sure if the 4Runners have an EGR valve, but when mine got clogged on my 95 jimmy, the car idled horribly, and the engine sounded very tinny. However, when I had my foot on the pedal the car ran a little better because the valve was open like it was supposed to be. However, you'd probably be getting some sort of code for the EGR valve if that was the problem (again, i don't even know if yours has one).

Anyways, good luck!!!

Try running some injector cleaner in your tank.

I had a cylinder 3 misfire up until recently. I also did the whole bit -- changed ignition parts, changed the fuel filter, etc. -- no improvement. But then I put a long screwdriver tip to the base of the cylinder 3 injector, while the engine was idling roughly, and I rested my ear on the handle. The lack of a ticking sound meant the injector was not firing. So I replaced the injector and voila! No more rough idle or hesitant acceleration.

Alternatively, your injectors may just be dirty. This may be remedied by adding injector cleaner to your tank or by getting a professional fuel system flush.

Good luck with your diagnosis.

thanks for the response guys gonna try some of those things.

I realize this is an old thread but I thought I would add some knowledge I gained from a good friend who is a Toyota mechanic. He says that when you wait too long on tuning a 3rd generation 3.4 the gap on the plugs will grow and the coil packs have to work harder. This can cause a misfire and wear out the coil packs.

Okay...i've been researching this topic for a while and just gave up. i've been having the same issue on my 2007 4runner with 33k miles that i recently purchased. I tried multiple types of fuel injector cleaner such as cheveron techron, redline, and bg44k. The funny thing is when the car has fuel injector in the tank the car runs well, however when there isn't any cleaner in the fuel tank, the same problem comes back. I cleaned the TB with no change and new air filter with no change.

I finally took it to Toyota and found that it was cylinder 4 misfire. They found that the spark plug had a slight crack in it and which caused all the problems. I've driven approximately 200 miles with no issues.

I hope this helps some people out there.

Riddle me this Batman....

I have a 2004 4runner limited, v6, auto xmsn.

My 4runner seems to hesitate, like a cylinder or two aren't firing. It only happens when the engine & xmsn are warm/operating temp, never when it's cold. Also only does it in drive or reverse - meaning at idle at a stoplight and in Neutral. Today I noticed that it is happening in all gears - all modes of driving. I get no CEL or codes of any kind (no hard or soft codes).

Suggestions?

I looked on the forum for clues and I'll go replace the air filter. It sounds like xmsn to me.

So it finally threw a code and it was a bad coil. The funny thing is that it took so long to finally give a code. It's been months of veerryy slow deterioration.

Anyway, thanks for the help y'all and Jeremy have a beer. You earned it!

i have a 1998 4runner that shakes at idle still, I changed plugs, wires filters, air cleaner, cleaned throttle body, 4 new injectors, motor and tranny mounts, checked every hose on engine, replaced a few that started to crack. it shakes while stopped but as soon as i hit the throttle it runs great, it will keep up with the v 6, runs incredibly well and great on fuel i get 245 miles on a full tank. i have had this runner sense brand new, it had 12 miles on the dash and it now reads 194000. i keep it up but this shaking is really trying my patients. and i have no codes, i unplugged a few things to see if the check engine light would come on and it did. thank you

I wrote about a problem with my 4Runner several months ago and I have done everything the replies said to and it still shakes at idle. It's a 98 4Runner i am the first owner, the truck runs really good, it moves. I own a few v8's so I am no stranger to what power feels like. It has no leaks I have no engine light and I have changed coil packs, injectors, plenum gasket, plugs, wires, checked so many times for cracked vaccume lines including air to intake, mass air meter, EGR, air idle control, tps, cleaned throttle body, changed fuel in tank, checked fuel pressure and pump, changed filter, fuel and.air, changed oil and filter, at 4000 miles, still gold in color. I do my own repairs on my 2013 Pete and others as well. So if I do not get it this round I am going to bury it in the back yard. Thank you

My 92 v6 idles roughly when in drive and stopped at a light or sign, shakes at the end of the engine being turned off while cold, and has started leaking oil more than usual right after being turned off.

Hi All,

I have a 3rd gen 4runner under 120000 miles and I have the same issue with rough idle at park, in addition it sputters under 3000 RPM & under 30mph , no CEL. It also feels like there is low power.

I have performed the following this far, (one item at a time to see if it resolved the issue but so far no luck)

1. Changed the spark plugs
2. Changed the air filter
3. Changed the fuel filter
4. Cleaned the throttle body
5. Checked for vacuum leaks with smoke and propane, no vacuum leak
6. Cleaned the MAF sensor
7. Changed the coil packs and plug wires.

Next item in line - :Use Seafoam
Next item in line - Replace Fuel Pump

Is there anything else I should look at that I haven't listed?

If you have symptoms of low power and sputtering at any rpm you might have a bad fuel pump.

Does it take forever to hit 60-65 mph at full throttle? If so it might be a fuel pump.

If it is only in one spot it could be a bad maf or throttle position sensor (tps) or cam sensor (if vvt).

Also might be worth rechecking the plugs. I've had issues where the store I bought the plugs from dropped them and I didn't see hair line cracks until I drove for 20-30 miles. After a while you'll see carbon tracking indicating a crack.

Hey guys (and gals),
This is my first post so bear with me here... I have a 2002 4Runner that is having an idle issue somewhat similar to others that I've read about but I cannot seem to find the cause. The car starts and runs perfectly and I average around 18-20 mpg which seems normal. However, when I am in Drive or Reverse and stopped the engine will give a fairly sharp vibration/shudder as if it were going to die but it never does. Sometimes this will persist every couple of seconds and other times it is more intermittent.

Thus far I have tried the following in search of a cure:
-replaced leaking valve cover gaskets
-cleaned the throttle body
-replaced in-line fuel filter
-replaced cracked section of intake hose
-Sea Foam in the fuel tank
-Sea Foam intake cleaner into the TB

The problem did go away for a couple of days after cleaning the TB but then returned. I have seen a number of people point to the IAC valve but IIRC the IAC valve is integrated into the TB on 2002's and cannot be serviced/cleaned. Is that correct? I am going to check for possible vacuum leaks but is there anything else that I may be missing? No CEL (tho I know it works).

If the issue is below 3000 rpm, then I don't think it is a fuel pump.

Try to find a junk yard and get the MAF and try it.

Looks like an MAF issue.

Its possible a leaking or malfunctioning injector could cause this.