Intermittent Start Up problem

[borlin]

I have a 2001 V6 AWD 48K miles Highlander LTD and about once every 7-10 days, for the last 6 months, the engine will die within seconds of start up. I'd have to accelerate while trying to start the engine, have it rev very high for about 3 minutes before the engine will remain on. The engine then runs a bit sluggish until I restart it. All other times, engine starts up quickly and without a problem. Took it to the dealer, but they couldn't find anything wrong with it.

I need you help

[drewdog]

what gas do you use (brand and octane) ?

[chrisc16]

Sounds like a bad TPS (Throttle Position Sensor) to me. I had the same exact symptoms on my 02 Tacoma and a new TPS solved it.

-Chris

[borlin]

Originally Posted by drewdog

what gas do you use (brand and octane) ?

Any brand but 91 Octane.

[drewdog]

Originally Posted by borlin

Any brand but 91 Octane.

ok. just curious because my aunt has a fairly recent toyota corolla, but it crapped out on her - mechanic blames the quality of gas she uses. both she and my uncle use the absolute cheapest gas they can find (and lowest octane). so i wondered if that was possible cause.

i found the higher quality gas gives me better mileage/performance than the cheap stuff, so it makes up for the little extra i pay....

[borlin]

After change TPS (Throttle Position Sensor) yesterday.
Still the same.
Is anyone know anything about this?

[t3mp]

I experienced a similar issue with two camry’s, mine and my cousin’s. We also replaced the tps sensor and that didn’t help. It’s something called the idle control valve? I’m not 100% sure what it’s called, but my younger brother who is a mechanic fixed it. All he did was clean it with carburetor cleaner.

I was about to type a description of the solution, but I found a good one on the Edmund forums. http://townhall-talk.edmunds.com/WebX?14@@.ef0c570!make=Toyota

The IAC or Intake Air Control Valve controls the engine speed at idle. It is controlled by the ECM.
Remove the rubber air intake (2) hoses at the throttle body and look inside the body. the tube on the right side has the IAC valve opening for air flow to bypass the throttle blades at idle.

It took me about an hour and half to disconnect and clean the IAC.

I disconnected the negative battery cable
removed the air filter
removed the connectors from the IAC and the throttle position sensor
I had to remove some black hoses from underneath the throttle body and on top of the air cleaner box get clearance that I would need later when I unbolted the throttle body from the intake manifold.
Remove the (3) bolts (2) on top and (1) on the bottom .
Also remove a screw from the firewall side of the throttle body to release it from the engine.

Turn the throttle body to remove the (4) phillips head screws.
There is a rubber gasket underneath, Because engine coolant does circulate through the valve, you only loose about a tablespoon of coolant. I did reuse the rubber gasket.
After you inspect it remove the electrical connector (2) screws carefully pull it away from the IAC.
Look for signs of carbon or scoring on the shaft that rotates also check the operation of the little door openning under the shaft, it opens and closes.
Mine didn't rotate freely and was dirty.(NOTE: the shaft only rotates enough to open and close the door beneath it.
I used a toothbrush and carb cleaner to free it up , the spray will empty out of the opening on the bottom.

It not difficult but there is never enough room to work under the hood.
Before you remove stuff , you have to check if there is a wire attached to it.
If you have a problem with your idle you might try spraying some carb cleaner through the opening in the throttle down to the IAC.

courtesy of Paul.

[borlin]

Thank you for you help. You just save my car. I just clean the "Thlottle Body Idle Speed Control Valve" yesterday. Problem Solved



Thank you very much.

[sledge]

t3mp,

Thanks for the good advice. Was having the exact same problem, and followed your excellent directions. When I got it back together, it started right up, and idles fine now.

Appreciate it....

[smcgough]

I wish to add my name to the list of grateful Highlander owners who benefitted from this thread. Fix works like a charm.


t3mp = Kudos

[Rob SJ]

To: t3mp, Thanks a million for the tip, my wife's 2001 Highlander, 94,000 miles had the exact same problem, last night I removed the throttle body and the IAC valve and cleaned it and then reassembled it all. It took me 3 hours total start to finish. The car starts and idles like new. The cold idle is @1500 RPM and once warmed up it's at @700. All is well.
Thanks again.

[ikaneva]

I had a similar problem with my 2001 V6 AWD (138K miles) Highlander. Without any particular pattern, for the last 4 months, first time in the morning, the engine would die within seconds of start up. I had to accelerate while trying to start the engine for 2-3 min before the engine idles. For the rest of the day as well as all other times, engine was starting up quickly even though it was idling a little low (500-700 rpm). After reading your message - bought Haynes repair manual, new IAC gasket at Toyota dealership. Cleaned IAC valve (it was gunked up!) with rubbing alcohol and Q-tips. PROBLEM SOLVED! Now It fills like car has more power! It has solid idle at 1000 rpm as it was when new.