cold start problem

You can see the earlier threads here are from 2001, on the same topic

-- so it's been going on for a while now. A few light sprays of emissions control safe carburetor cleaner in the small rectangular hole at the bottom of the throttle body with the car idling cold will solve it. Search "IAC" in this group for more.

I own a 97 Camry 4 cylinder myself and the spray-out method didn't work for me. If the pintel is stuck, there's no guarantee it'll unstick. My starting problem was intermittent, then I had Firestone spray out the IAC and the problem became permanent. Took it to the dealer (at Firestone's request), the lousy IAC was diagnosed as bad. $385 later with a new valve installed, the car fires right up and will do so for YEARS. It's your money and your call. The IAC was $222, installation was $140 so you're looking at some real money here.

The dealers do ALOT of these, they knew what to do right away and did it right. You might want to try a fuel induction service. That should clean everything out in there. The problem will probably return in 6-9 months, but it'll buy you time if you want to trad the car away.

Didn't want to say anything, since you had already done this, but if I remember correctly Firestone emptied something like two or more full cans of cleaner and still failed to improve anything. Personally, I would never take my car to Firestone. Occasionally you can find a great mechanic at an unlikely place, but generally, my experience has been that they are less than completely honest or competent.

I started working with cleaning the idle air control valve because the prior owner already had the dealer replace it - as you say not inexpensive, and the problem returned.

With just a very light spray of Berryman, the problem can be corrected in a few minutes at virtually zero cost, with a single 10mm wrench, by removing only one hose clamp. The old IAC valve, works beautifully now.

Firestone had no business dumping that much cleaner through the throttle body. That kind of behaviour can create additional problems.

The Firestone tech said that they sprayed it into the IAC opening until it ran out clear, so the fluid was running out of the housing where they were seeing it flow They probably removed part of the fitting to spray it out real good...whether they broke the pintel is hard to determine. They made a good faith effort and were honest enough to throw in the towel when it went over their heads. I have no beef with them.

I've seen other posts where they recommend doing a "bench cleaning" of the valve. Another post claims that you have to disengage some kind of motor from the throttle body before spraying out the IAC. Everyone agrees it's a band-aid repair...kind of like repairing your radiator by adding a sealer. Cheap can be good...but in the long run?

There's all sorts of theories..... Another poster says Toyota techs won't bench clean the IAC's anymore because it'll just keep happening.. I look at it this way, if it took six years for this problem to develop on my Camry, it won't be back for a couple of years at least, if it does, I get a fuel induction service to free it up for 6 months which will be just long enough time to shop for a brand-new Chevrolet. The only shining star for Toyota is the great service I received at the dealer, expensive yes, but well worth every penny.

I look at

Fuel induction service cleans the fuel injectors. This is not related to the idle control valve. Second, I suspect you're overestimating the utility of the IAC valve replacement. Generally, the electric step motor, and wiring do not go bad. If they actually did test faulty, then I agree to replace the valve. As your engine ages, oil vapor through the PCV valve may increase, which means you will not get the same life out of the replacment IAC as you did when the car was new. But, my friend, you are free to follow your own heart. If you feel better about paying to have the IAC valve replaced periodically, that's fine with me.

Idle AIR control meters only air - cleaning fuel injectors wouldn't touch it.

Fuel Injection Induction Service Basics: The difference between a dirty and clean fuel injection system can be measured in tangible symptoms such as: hesitation, rough idling, engine run-on, pinging and knocking, poor acceleration, lost power and performance, and high exhaust emissions. This regular maintenance routine will help a car run more like new.

What This Means: By cleaning the fuel injectors, intake valves, throttle body, air intake, cylinder heads, pistons and rings, lost performance is brought back. The engine will be cleaned at these points, allowing fuel to be processed more effectively.

The Results: Horsepower returns as performance is increased. Exhaust emissions and foul exhaust odors are reduced while hesitation is eliminated and gas mileage improves.

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Just my personal opinion, but I wouldn't go to Midas either.

Or Pep Boys.

Use the Toyota dealer, or see if you can find a qualified independent mechanic who specializes in Toyota, or learn to do your own work.

Naturally, Midas will justify and sell the services they provide. For example, I hear their lifetime free brake replacement pertains only to the pads themselves, excluding additional labor which is always required and adds substantially to the cost.

If you want to clean the injectors and fuel system, read the technical information at:

I've been to mechanics who have left the cotter pin out of a lower ball joint causing the car to come crashing to the ground months later, fail to drain transaxle oil properly, leave spark plugs finger tight, over fill oil by seven quarts, leave newly installed muffler hanger rattling against the frame, rebuild a manual four speed transmission so it only shifts into three gears and the clutch improperly adjusted, -- and I'm sure there are others. If I understand correctly, you just had a bad experience with Firestone, paying them and then going to the dealer for another $388 repair. I wouldn't expect Midas to be much different, but these franchises have been in business for many years, lots of people must be using them, but I think you can do better.

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I was curious about the word 'pintle' (alternative spelling) and found it to be a piece of metal which pivots allowing a valve or rudder to move.

The Idle speed control system used by Toyota involves a stepper motor and IAC with something like 44 possible positions, giving very fine control of the air allowed to bypass the throttle valve and hence alter engine idle speed. . From what I gleaned from the web,..if the pintel becomes sticky or not free in its movement, the engine idle will suffer. Why does it get this way? Apparently the air quality which is controlled by the IAC can be quite poor if the engine is worn because the PCV valve is located close by,..upstream of incoming air.

If the IAC requires repeated cleans, it maybe the valve is scored and can no longer provide smooth operation.

Just my take on the situation.

Jason

by the

Jason: The PCV valve is located DOWNSTREAM from the IAC ("downstream" meaning after the throttle plate, plumbed into the intake manifold -high vacuum-). The OTHER vent path from the valve cover or crankcase is to a port UPSTREAM of the throttle plate but downstream of the air filter. Anytime blowby volume exceeds the flow rate of the PCV valve, the crankcase now vents that excess blowby thru the hose upstream of the throttle plate. This blowby carries oil and combustion byproducts which accumulate in the small IAC circuit. The correct cleaning procedure is to unplug the IAC while the engine is Hot (ensures the pintle is extended), then shut off the engine. Now remove the IAC from the throttle body and clean thoroughly. Reinstall.

I was complaining to a plumber friend of mine that when I had the dual faucets replaced in my bathroom (because one was broken), the landlord's plumber replaced both (the style was no longer produced) and trashed both, even though one faucet was perfectly good. My friend said he would've done the same thing, when you reuse fixtures, no matter the condition, it comes back to bite you every time. If you're going through the hardship of removing the entire valve from the throttle body you should replace it. I know $220 is a big hit for the valve, but time and labor ain't cheap either.

Now I'm not go>>snip> The Idle speed control system used by Toyota involves a stepper motor

The OTHER vent path from the valve cover or crankcase is to a

Interesting. All the explanatiions in manuals describe how this port supplies fresh air, but they usually don't mention this secondary mode of operation.

I'm not going to reply to your opinions in this thread any longer, we're just rehashing the same point, and you're certainly free to differ. Who knows, maybe you're right. To use the plumbing analogy, I'd liken cleaning the IAC to unthreading the mesh screen at the end of the faucet and cleaning it, rather than buying a new mesh screen, because the IAC valve is unlikely to suffer mechanical wear or corrosion, unlike plumbing fixtures. It just sticks with a teensy tiny bit of contaminant, and that's enough to upset its precise metering of air. Once it's free to move again, all is well. New part, existing part, same story. Believe me, if I thought I'd get better or longer lasting results by buying the new part, I would. Personally, I replace parts that aren't malfunctioning just as a general part of preventative maintenance to ensure optimum condition. Such things as fuel cap, PCV valve and grommet, fuel filter, water pump, spark plug wires by mileage, etc.

It is NOT a bit expenditure of time to remove/clean/reinstall the IAC. But if you're going to have to pay someone to do it, then that's the price of staying uninvolved. It's not a big deal.

If one considers IAC devices have been with us since the last 1970's ... there should be no one calling themselves a "mechanic" that does not understand the inner workings of an IAC.

You're so lucky to have me fleshing out .... "The rest of the story." ;-)

Don't kid yourself, cost is a big factor, this is a $220 part here, if it were a $20 part you would install a new one in a second. Imagine if spark plugs were $50 each, everyone would be cleaning them like crazy too.

The short answer is 'yes', retired to something less nerve wracking and now ... retired completely. :-)

There are LOADS of specialty tools. There is no such thing as a vehicle that doesn't require at least a few such tools. Of course I have a couple of drawers full of specialty tools I've made by cutting off an end, or welding to, or grinding a bit off of otherwise perfectly good hand tools. Making your own is part of being a mechanic. Otherwise, Snap-On, Matco, and the rest will own your paychecks for some years to come.