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To any who may have insight into this, advice will be appreciated!!!

My wife has a 1997 Toyota Camry, 2.2L 4-cylinder, 140,000 miles approximately. For the last several months the car has been suffering with an intermittent starting problem. It does not happen all the time, though lately it has been occurring more and more.

Problem description:
Upon turning the key the first time, the vehicle will begin to start then will sputter and die, failing to make the final crank to fully activate the engine. In the past, pressing on the gas pedal has started the car (likely a coincidence since the car is fuel injected). After the third or fourth time turning the key the car usually turns over and starts. This happens once a day, sometimes in the morning and sometimes in the afternoon.

Here is the problem. As of today the car has been in the repair shop for three days without experiencing the problem. It has started up fine all three days. As you all know, if the mechanic does not have the problem occur while in the shop, they cannot determine what is wrong with it. We have already had the spark plugs changed, fuel filter cleaned, wiring repaired and air filter cleaned and the problem still happens (the previous repairs were done in response to this very problem). The battery is brand new as of December. We are running out of possibilities and cannot continue to pour money into POSSIBLE causes.

Anyone that can offer insight into the possible problem, please respond. Anyone who has had this EXACT problem with a similiar car and knows the cause and repairs needed, please respond quickly. I thank you all for your attention to this email and your advice.

K. Ranoldo  

carefully note and mark the position of the hoses to the throttle body...     some are vacuum.. some are coolant..    you don;t want to mix them up..

remove the throttle body.. turn it over.. remove the idle air control valve from the bottom of the throttle body..





remove the electric part from the end of the idle air control valve..  

use spray cleaner to clean the shutter valve while rocking the knob on the shaft that fits inside the electric part back and forth..

there is no need to replace it.. it is just filled with carbon..

clean the throttle body bore also...   do not let cleaner spray into the TPS sensor on the end of the shaft..   hold the throttle body with the TPS upward...  wipe the bore and the throttle blade clean ..

put it all back on...  

i would also like you to verify.. with a vacuum gauge hooked to the EGR hose..  that when the engine is warmed up and driving down the road. that there is vacuum signal getting to the EGR valve...   there is a plastic valve  with several hoses near the egr valve.. the bottom hoses goes to the small tube on the base of the EGR valve.. that is the exhaust back pressure transducer.   it its bad..  it will not activate the EGR valve and serious engine damage may happen..    more later tonight.. be sure to post that you got this...    

this is the part i am talking about ... the brown end plugs into the side of the bottom of the EGR valve... when the exhaust back pressure comes up.. the internal diaphragm closes and allows vacuum to reach the EGR valve to make it operate... when this fails...  the EGR does not work...  the check engine light will come on.. the fuel mileage will be reduced...    




when the EGR fails to properly operate...  the engine runs lean... as there is more burnable atmosphere in the engine for the percentage of fuel...   this can get bad enough to damage pistons.... melts the sides and rips the rings off the sides....  

yes.. that exact problem..  and the second problem also...


one thing....   DO NOT use a Phillips screw driver on the screws that hold the idle air control valve to the throttle body... and do not use a phillips screw driver on the screws that hold the electric part to the end...

they are POSI drive... the proper driver will be a POSI drive...  with  PZ not a P on it...   use the wrong screw driver.. it will usually round out the cross and you will have a problem getting them out...

 

i was in a hurry to get away..

the idle air control valve is controlled by the computer...

when the engine is cold.. and you turn the key on.. it sends a voltage to the black electromagnet shown above...

the larger the voltage.. the more larger the shutter valve is opened...   so at low engine temps.. this can instantly control the idle speed to keep the engine revved up to warm it up...

during normal operation as loads on the engine come on.. like putting the transmission from neutral into drive...  turning on the AC compressor.. turning the steering wheel which loads the power steering pump...   the computer can instantly control the idle speed of the engine by changing the voltage to this part...

what happens...   carbon from the EGR system... Oil vapors from the PCV system coat the insides of the intake manifold..

when you shut off the motor.. the throttle valve blade is closed...  the only opening for any HOT air trapped in the intake manifold can really exit is through the idle air control valves shutter wheel.. this causes carbon and oil vapors to build up in the shutter blades causing it to drag and hang up...

there is NO gear reduction direct connection between the electrical portion.. and the shaft..  the shaft only turns about 1/4 of a turn..    the return spring is not very strong nor should it be...

it just needs to be taken apart carefully...   and cleaned...

new ones are available from many parts stores...  somewhere between 220 and 400 bucks depending upon where you buy it.. so cleaning it makes sense... if you have the mechanical skills...