True statments vehicles are generally stressed during extreme cool but if its doing during while of driving then yes it is another issue than it just not being warm. You have a 97 its gonna need a bit more of a tune to tune than new vehicles. Make sure it has oil and everything is connected. Hopping in a vehcile and driving off at 30 some degrees is very hard on it. Gotta let those fluids get flowing.
Your list you need to consider on fixes:
-------------------------------------
O2 Sensor
Caddy Converter Knock out
Plugs and Wires
Air Filter which you did!!!!
Check the vacum and Air Intake System
And as a last resourt Get your Injectors Cleaned

If its none of these then you got big probs and you may have to consult your local Toyota dealer today. <Joke
__________________________________________________ ________
95 Toyota 4-runner SR5 V6 3.0 Automatic 149,600 Miles (bone stock)

 

Plugs are recently new but I'm thinking I need to get some new wires and an o2 sensor...these should be done anyhow I think after 140k miles and I'm guessing both are original

 

Have you even had a valve adj? We see so many of these things with the 4cyl's that have tight valves. That would for sure affect your running. No one asked this....does your temp gauge indicate a normal operating temp? Stuck open tstat will make your engine run colder and will also affect drivability

 

And you are right...don't just throw parts at something. Doing that just wastes time and money

 

Stupid question - what's a TPS??

 

TPS is the Throttle position sensor also known as a pedal position sensor. It is a wound coil (potentiometer) that turns with the butterfly valve in the throttle body to act as an input to the ECU.

 

Exactly what he said! Haha,

The temp gauge shows everything to be ok, I mean it gets warmed up according to that so its not the tstat.

If I needed a valve job, wouldn't I notice something throughout the engine temp range and driving range? There doesn't seem to be any chatter or anything like that...

I did check the resistance on the TPS and everything checked out there so thats not the culprit. I checked for vacuum leaks by spraying throttle body cleaner on the intake and EVAP lines and didn't notice anything.

Monday I'm going to order the o2 sensor and wires I think...like I said earlier, it can't hurt.

Still just guessing at this though...the next option has gotta be injectors but again I just think I'd notice this throughout the driving range. Ugh...

 

you seafoamed the heck out of her yet? Yeah it may not work, but it can't hurt. And if it did work... well its a lot cheaper than O2 sensors.

And if it were an O2 sensor, should't it throw a CEL?

 

No I haven't sea-foamed...I just cleaned the throttle body though. I guess I could try sea-foam, then I'd bet the O2 sensor would throw a code once all the sea-foam crap works through.

It doesn't have to throw a code, I mean it may not be fouled up enough yet to throw one. I figure after 140k miles though, the front one has got to have some crap on it. I'm getting like 13-14 mpg right now so I'd bet the O2 won't hurt to be changed, thats a whole other thing...haha...i think its just because its been in the single digits this past week.

 

Ouch... I've been getting 20-22 in the city and I have a V6. But no single digit temps in south carolina, thats for sure

 

I'm having the same problem. Although I have a 2000 with the V6. It became noticable after I changed the O2 sensor this weekend. Plugs are fairly new same with the air filter, new. I cleared the code with a scanner, that didn't help so I disconnected the battery for a few hours, that didn't help.

 

Hmmm...i changed the air filter and that seemed to help a bit but not much. I'm going to try and run BK44 through it, and maybe get some injectors.

 

so did you ever find out what happened? what worked or didn't work. I'm starting to get this problem and it's getting progressively worse. thanks.

 

TPS = throttle position sensor

 

oops (last post) - newbie mistake - didn't see page 2!

Anyway - I'm also having a smilar problem - any updates on what worked?

 

I'm still having the same issue.

2000 4-Runner, V-6, bone stock, 190K. Here's what mine is doing...

I start it in the morning. It starts fine, has a high (warm up) idle for a long time. After about 2-4 minutes, the engine starts surging. Not a major surge, just a noticeable up and down, rhythmic surge. Probably 200-400 RPM difference.

It sometimes goes away once the vehicle is warmed up and driven for a while, but other times it doesn't. If I'm cruising on the highway or especially up a long gradual incline, it's very noticeable. Again, not a major surge, just a few hundred RPM difference.

I don't have the best gas mileage in the world and it definitely doesn't have a lot of "snap" in the throttle or "get up and go" when I mash the pedal.

I've seafoamed the crap out of it, ran multiple different "ice/water" cleaners, and fuel injector cleaners.

Does anyone have any other ideas? I was thinking maybe the MAF, IAC, or TPS? But as others have stated, I don't want to just start throwing parts at it. That really adds up, you can't return them, and it may not solve the problem.

PLEASE HELP! This is driving me nuts!

 

Anyone have any ideas? Unfortunately, I'm still having this issue. I just haven't got around to researching a cure yet.

I can't be the only one with this issue.....It's driving me nuts!

Any help would be great. Thanks!

 

I have a '95 tacoma with a 2.4 liter. It just started doing the same thing. Surging when the engine is cold. Ambient temp doesn't seem to matter. The surging mostly goes away when the engine is hot.
I'm wondering if it's not the engine temp sensor. Not the sensor that runs the coolant gauge on the dash. On my '95 there is a themistor (I think it's called) on the back of the engine that sends a signal to the computer.
Does anyone know if the O2 sensors can cause these symptoms?

 

I wondered about the temp sensor too. I don't think an O2 sensor would cause that rhythmic surge.

I've often wondered if it could be the idle air control valve (IAC)?

Does anyone have any ideas?

 

IAC. Had this symptom before on 2 other vehicles.