Darwin

I was on the interstate a couple days ago. Cruising about 70mph and my 4Runner just starts decelerating like it's out of gas but I have over a quarter tank of gas. No sputtering or other weird sounds/behavior. I manage to coast off an exit and let it sit for about 30 minutes. Still won't start. The engine cranks but won't turn over.

Have it towed to a mechanic. He tells me it's the Idle Control Unit and it will be $565 to replace.

Pretty sure I can do it myself and save at least $300. But I'm just questioning whether that is really the problem.

I guess something just smells fishy. Any input?

mt_goat

I would think the idle control valve(?) would mainly effect the idle, not shut down at highway speed. But I'm no expert.

MaK92-4RnR

ICV should only effect the idle. My truck needed a new one and all it did was "lope" at idle when i first started it. When i hit the gas, it would go back to normal and then shortly after lope again there after.

I would think its a VAFM or TPS if it stalled while you were driving.

Darwin

Thanks for the replies. I've been reading a lot about ICVs this morning. It seems the reason people have to replace this part is because of starting and idling issues. Granted, my 4Runner is not starting, but the ICV doesn't seem to explain why I suddenly stalled at highway speed. The high price tag for this work makes me not trust the mechanic (new to the area and the mechanic).

Darwin

Anyone else have any advice on whether the ICV is the culprit and if $565 is a reasonable charge for replacement? I think I'm going to have it towed to another mechanic for a second opinion. I just called a local Toyota dealer and they quoted me $160 labor to replace the ICV.

J2F42C

It could be gunked up to the point where the valve will not move. But this would be a first that I have heard of an IAC causing the sudden dying of an auto. Ever cleaned the TB?

Could you hear the fuel pump come on when the key was turned over? When pumps die, the car/truck/SUV stops.

Darwin

I have never cleaned the TB.

I did assume the problem would be the fuel pump. Hence my surprise (and current doubt) that it's the ICV. I don't recall hearing the pump come on when I turned the key. I listen for the sound every time I start my 4Runner but this time I was distracted and don't recall if I heard it or not.

J2F42C

I'd have the mechanic run a fuel pressure test as well as listen for the pump.

Ever changed the fuel filter?

sharrack

yea..... back to basics...... no start condition.
check fuses
check for fuel at the throttle body
check for spark.

my runner did something similar last weekend
and only not started for an hour.
then ran .... no problem but did stall exiting
the hwy at 65.
just realized my mass airflow sensor had bugs stuck
to the sensors.... we drove through a fog of bugs minutes
before it stalled... makes sense!
cant imagine the ICV causing a no start condition.
kenny s

Darwin

Here's an update:

Mechanic #2 said the problem is the cam shaft position sensor. I told Mechanic #2 that another mechanic said the problem was the idle control valve and Mechanic #2 said they hooked it up to a computer to diagnose and are confident it's the cam shaft position sensor. I'm not sure what to think at this point.

DRCOFFEE

That sounds more like the issue. That would be a valid reason for it to stall on the road.

Darwin

Here's another update:

The cam shaft position sensor was replaced and that did not fix the problem. So mechanic #2 remembered me telling him that mechanic #1 said it was the ICV, so they replaced the ICV. Still won't start. They did a fuel pressure test and the pressure is good. They are currently doing more troubleshooting.

DRCOFFEE

Just tossing this out there. Is the air intake blocked? Maybe something (rat, squirell) crawled into the fender air intake.

Will it temporarily fire up with the intake tube removed from the throttlebody?

It may be a burned wire. Check around the engine for a wire near the exhaust. You said it stopped suddenly on the road. Something failed at that moment. Check for broken wires under the truck.

kball

Have them check to see if your timing belt broke.

sharrack

Check for bugs on your mass airflow sensor. Just happened to me.
Truck stalled on highway.
Here's the pics, kenny s

Alpine114

Experiencing some similar problems with my 1999 4runner 3.4 but also some other interesting ones. Background: My 4runner had a CEL on for a while, and one day i was driving it, the engine starting making a loud ticking sound, and needless to say, i should have stopped driving there instead of attempting to get it home. Ended up blowing up a loose spark plug. Had the mechanic tap and die new threads in, and it ran well after. I was still getting sub par mpg, around 11, and my cel was still on. So I finally decided to cough up the money to replace timing belt, water pump, and to address the CEL. $1000.00 later, they replaced rear O2 sensor, TPS, Timing belt, Water Pump, Thermostat. Drove it 2 miles from mechanic, cel came back on, and chugging at 2000-3000 rpms...but not below or above, its a manual transmission btw. Also, usually it idles around 750 rpms, now around 1500+. Codes read as insufficient coolant temp( i didn't replace coolant temp sensor, but if i unplugged it, the idle dropped back down to 750rpms, if this means anything) and i forget the other code number, but suggested toward Front O2 sensor. I bought a new denso O2 sensor for front, installed it, and managed to get light off after battery reset, but still same symptoms.....high idle, and jerking/chugging at 2000-3000 rpms... Also in the past, i have cleaned the throttle body, and had a new MAF sensor. Took it to stealership last week, and they think its the IAC. Is it possible that once the mechanic changed out the tps, O2, etc that those parts were actually masking the chugging/jerking problem, and once they were fixed, it wasnt getting the same accelerated fuel supply or whatever as before,or is that just crazy talk?...frustrated and in need of suggestions. thanks in advance.