Skrillah

Hey guys,

As the title describes, I'm having a problem with my engine "surging" when I'm hitting the highway on these cold mornings. I notice the engine RPMs dip very slightly when accelerating, it almost feels like the truck gets hit with a big gust of wind every second or two.

I don't notice it much at idle and it seems to go away once the engine warms up. The plugs are pretty new, plug wires look good, its been probably 2 years (20k miles) since the PCV was replaced, air filter is clean.

Could this be some kind of vacuum leak? I've cleaned the whole intake system, throttle body, and MAF but still having the issue.

Your insight is very much appreciated!

Thanks, Kyle

Skrillah

I know this is a boring topic but come on...someone has to help me out!

Mock Knight

I just got a 97 taco 3RZ powered and am experincing the same probs.....

Skrillah

Yeah I'm not sure the cause...coil packs or wires maybe...dunno

Skrillah

or the tps...?

Allstar93088

does it feel like its stalling out when you get into the accelerator? and finally kick in like its supposed to be?

Skrillah

Yeah, kind of. The best way I can describe it is that it feels like a big wind gust is hitting me constantly...

Allstar93088

Yea i having the same problem but i have 22re. It just stalls to me I can hold my foot to floor and get nothing but lil movement then finally it kicks in...but soon as it warms up it doesnt do it! really wierd...

Skrillah

Hmmm...that sounds more tranny related

Allstar93088

i dont think its in the tranny...its really difficult to explain. It drives ok it just dont have the go to it like it ought too...I know its a 22re but it just dont drive like it ought too until u get it warm

Kiroshu

If its surging its prolly either Missing or a Vacum leak.
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95 Toyota 4-runner SR5 V6 3.0 Automatic 149,500 Miles (bone stock)

07sbock

Its cold. Let her warm up. if its not cold then it sounds like you have an ignition or vacume problem. Plug a code reader up to it and see if anything is on it.

Skrillah

If it is one of these things...could you point me in the right direction of where to start looking?

Kiroshu

Check for vacum leaks trun on the engine and listen any whistling noise and its prolly it. But if not then you might need something simelike a new air filter or something complicated like new vacum or intake hoses. If its missing which it might not be. Does it rumble or shake during idling? If so i would recomend you check your spark plugs and wire they may need replacing.
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95 Toyota 4-runner SR5 V6 3.0 Automatic 149,500 Miles (bone stock)

Kiroshu

Your runner is a 97 i would recomend you knock out the caddy converter too it will give you and extra boost of horsepower.
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95 Toyota 4-runner SR5 V6 3.0 149,500 Miles (bone stock)

Skrillah

I bought a new air filter today so we'll check that out. It doesn't really shake during idle, not excessive lets put it that way. I'm also looking into spark plug wires as we speak.

The exhaust is a summer job, I'm going to completely re-do it, and throw out the caddy then.

Could this be a an o2 sensor?

kmcaprice14

Thats where I'm putting my money. I had a rough idle and the car would sometimes surge for no reason. Plus at idle, I would sometimes tap the gas to correct the high idle, and as I layed into the throttle, the revs would DROP. I swapped out the TPS yesterday ($50 at autozone), replaced it in 5 minutes (as long as you have a stubby phillips head and a strong will not to strip the screws)... now she runs like a kitten. Plus gas mileage improved a bit too. I have 200 miles so far on half a tank!

beatenyota

o2 sensors rarely go bad. unless you used an octane booster with lead additives, or non-sensor safe silicon, it's unlikely the problem. antifreeze getting in the combustion chamber (headgasket leak) would also wipe them out.


If your truck isn't warmed up, it's gonna be running like anyways cause the PCM is in open loop. Give it 5 minutes before you head out on those cold mornings.

It could be a TPS but I can't explain why that wouldn't have the same effect when it is warm.

Maybe check your injectors / run some cleaner through there.

My sneaking suspicion is water in the gas. Rapid changes in temp will cause condensation in your tank. If it's real cold, there will be frozen water on the sides of the tank, and once your truck warms up a bit that will met, and obviously water in the gas is not good for an engine.

Take your filter off, pour out the contents, and look for water. It should be easy to see; bubbles on the surface. Try lighting it (away from other flammable materials) If it doesn't all burn.......... there you go. water. Replace the filter and maybe add a little dry gas.


Sorry I couldn't help more but there's a few of my ideas. I'm leaning toward the water in the gas, or just the fact that your rig needs to warm up before its running properly.

beatenyota

oh and let me know what you find out. My tacoma was doing this earlier in the winter. seems to have gone away now, leading me to believe maybe I had some water in the tank.

Skrillah

Thanks for the replies guys...

I'm thinking the TPS as well but I hate to just throw parts at it. I'm gonna rig it up to my multimeter and test it. I have to agree with Beatenyota that this doesn't sound like the culprit only because it doesn't do it when its warm which to me would be sure sign...although, maybe it does do it I just don't notice. Hard tellin until I get it hooked up...

Unfortunately, I can't test out your gas theory because I've got the 2.7L. The filter is located under the intake and is hard to access unless you're going through the wheel well with the tire off and a lot of busted up knuckles. Believe me I just did back in August, I wish it was under the chassis like the 3.4's....While that may be true, I'll just have to let this tank dry out.

I'll keep ya'll posted, I"m going to go do some work on her now...BURRR!