I have a 92 4runner V6, It havs a miss/stumble/sputter at low rpms especially under a slight load. Dealer replaced coil, plugs, wires, TPS, fuel filter, fuel pump and it is still there. It is not throwing codes and the service MGR basically told me without throwing alot more money at it he couldn't fix it because the techs don't know what it is....HELP!!!

 

did they check EGR function, etc?

 

Check all the vacuum hoses going to the EGR system.

Valves been adjusted ever?

 

Nineball,
I have no idea what the problem is, but I can relate to your experience. It annoys me to no end when you go to the dealership...the last place you want to go...and they change a bunch of parts and charge you crazy money and then the problem isn't even solved. That really annoys me. Of all the people who should know what is going on don't because they rely too much on codes.

Question, could it possibly be a head gasket problem? Maybe there is some coolant fouling out a spark plug or something?

Another question, could it be some wires have gotten too close to your engine and exposed some wires? This happened to someone on here as I read the post yesterday. He found some wires had fallen onto the engine behind the EFI inductor towards the back of the engine.

I feel your pain.

 

Find a dealership that has a tech old enough to be born before your vehicle, preferably one who was old enough to work on your vehicle when it was new. I'll bet $10 a good Toyota Master Tech who has 25+ years like mine does could diagnose/fix it in less than an hour.

EDIT: I have nothing against those younger than myself or young mechanics. Old dogs can learn new tricks...it's the new dogs that can't learn the old tricks without an old dog to teach them. I also would not have paid for their "guesses". You either fix it or you don't...no such thing as a "maybe".

Good luck.



Random Rant: It kills me how so few people know the person(s) that work on their vehicles by name or know anything about them. What other thing that you possess is as important as the safety and proper function of your vehicle? My service manager probably hates to see me coming, but I dang sure get my vehicle fixed properly when I take it to the dealer. And knowing my mechanic by face/name has been very beneficial many times and I do not mind paying for excellent service.

 

don't know about the EGR, I have heard you can plug some of the hoses going into it and basically render it useless, if anybody know how to do this please let me know. As far as the valves being adjusted it had a new long block put in 20k miles ago....

 

there is a vacuum hose going into the top of it. pull it and stick a screwdriver bit or something in it. that's what is in mine right now. took away teh stumble, grumble until i can get some time to repair/replace the items needed.

 

Wabbitt,
I never thought about the age of the mechanics as being a determining factor as to where I bring my truck. From now on- when I absolutely have to bring my truck to the dealer- I'm going to ask how old their oldest mechanic is.

 

Wabbit is full of all sorts of useful tips and ideas.

 

I'd be pissed too.. You don't pay for guesswork. At a minimum they should give you the labor for free and just charge for parts.

 

You said coil, plugs, and wires, but didn't mention dist cap and rotor. That would be the first place I'd look.

 

X2, this message is to short, so now it is longer.

 

cap and rotor also done.....

 

Check and clean the IAC on the throttle body. Due to the way the pvc vavle is routed back into the intake it gets clogged up with oil. Cleaned mine out and no more stumble.

 

all good advice, check egr . but just blocking the vacuum hose may not be the total answer. you may also have to block off the valve from the plenumn. and age isnt always a determining factor in choosing your tech. im only in my early 30s but ive been a toyota tech since 93.

 

IAC? Definition please...

 

How about the fuel pressure regulator?? I would check the fuel pressure on the fuel rail.

 

37lbs

 

It had the recall done?

Anybody check the compression?

 

idle air control valve. you will see a little port in the throttle body, that leads to it. spray it out with some throttle body cleaner and then blow it out w/ an air gun. iv fixed a lot of problems this way.