solarae

have a 98 2.7 liter, 5speed 4Runner. For several months now I have had a symptom that I thought was water in the gas. At any given moment under load but often when you ease up for a moment and then give more throttle. The truck will cut out for a second. It could be a soft hiccup or a sharp jerk. Sometimes it comes in multiples. Never really stalls but it sometimes feels as though it might. I used alchohol and "HEET". Sometimes it seemed better, sometimes worse. I changed the fuel filter a while back and today I dropped my gas tank, emptied it and dried it and put in fresh gas. It still does it. Any clues?

seanz0rz

change spark plugs and wires with OEM units from toyota (northridge toyota has 20% off)

jimig

I would also add PCV valve while your under there.

toytech76

Before you go throwing a ton of parts at it that it may not need, do some or get some diagnostic work done. Dont say you cant afford it because its gonna cost you that much by buying unneccisary parts for it and not fixing it. Do some simple things like cleaning your MAF, looking for air leaks, ect. If nothing works without buying parts, go get it diagnosed and have it fixed properly

seanz0rz

sparkplugs are 2 dollars each from the dealer, and probably need to be done anyway. wires are a bit more, they wanted 60 or so, i found mine online, but wish i had gone with OEM toyota (and will next time).

i replaced those along with a new fuel filter and that solved my similar problem of stumbling on the freeway around 50 mph. never had a code.

while im not greatly familiar with the 2.7l I4, i know the 5vz-fe is very picky about sparkplugs, and the stock denso plugs work the best.

items like the maf and vacuum leaks, while they should be gone over, should not be causing the problem described. while you are cleaning the maf, you mine as well go about scrubbing down the throttle body and idle air control valve.

some more details might be useful in diagnosing this problem. does it happen when cold or hot? what RPM range (for example mine only happened around 1800 rpm), etc. every detail helps. diagnostics might not help unless you are running them and recording while it happens.

solarae

I really don't think it's the plugs. The symptom is: you are going down the road at any speed and the truck goes HUK HUK and kinda jerks like it all cuts out for a sec. Then it proceeds like nothing happened. Been doing it on and off for months. I replaced the plugs last summer with NGK. I did use aftermarket wires because I broke one of the Toyota ones and of course the dealership was closed. I could replace the wires but for these symptoms it would have to be all plugs or wires all at once. Just a misfire would not make the truck cut out like that. Maybe its the fuel injection. I live in a rural area where most of the mechanics are not very sophisticated and the dealership is a notorious crook so I need ideas from you guys. Thanks.

shell_bunner

I have the same problem with my 2.7 and I'm taking it to a reputable mechanic in the coming weeks. Under load it's hic cup's and stutters, and full throttle it feels like I'm riding a machine gun.

I'm gonna have the fuel filter, spark plugs, wires, and whatever else needs replacing put in. Putting a new air filter in today.

Like the previous poster, I need some suggestions about what it could be. I think it's something with dirty injectors or something along those lines.

Thanx

solarae

Did the plugs and wires. Plugs looked absolutely perfect. Symptoms seemed to be worse right after dropping the tank and only putting in 7 gals of gas so I let it sit a couple of days and then did the plugs and wires. Drove it 30 miles on a fresh tank of gas and symptoms seemed diminished but still definatley there. To recap: Truck idles fine, runs fine, but under load and often when you let up on throttle and then resume load (but could be anytime) truck chugs. Could be soft, could be hard enough to make the truck jerk, could be single, could be multiple, could be short (usually) but occasionally as long as 2-3 seconds going down the freeway at which time I think it might stall but it never does. Been doing it for months. Symptoms almost went away a few times but came back. Never breaks down completely.

deines97runnah

The important part of the story........Never breaks down!

97ltd4x4

I would check the intake boot between the throttle body and MAF for leaks/cracks,When the motor torques up on the mounts it could pull the cracks open and let in un-metered air.Could have a tps going out of range just enough to not throw a code.