Fuel/Emission/ Electrical/Other?

I have a 1987 automatic 2.0 Camry. I have replaced engine compartment fuel filter, in-tank filter, fuel pump, coil, EFI relay and still the car will just stop running at low rpms and sometimes when I put it in drive. Sometimes it will start right back up and other times it will take sitting for hours. Sometimes the engine has to turn over a lot and when it finally starts it sputters and the exhaust almost smells like old fuel (with good fuel in the tank). The check engine light has never come on and car has new battery too.  Any ideas?
 
P.S. I''ve driven this car hundreds of miles without incident and then sometimes I can''t even get out of the driveway.

Hello,
in response to your symptoms...
It could be a short somewhere on the primary side of the coil. My car just quit in the middle of the road one day.  Investigation found that the condenser under the coil was internally shorted.  Since it was used only for radio suppression, I just clipped the lead and everything went OK.  Recently it stalled again in my driveway and I discovered by testing that the coil was bad.  It could have been bad from the previous incident due to high currents through the coil. 
 
So...investigate the Primary path of the coil to see if there is possibly an intermitten short circuit to the supply side of the primary.
 
Doug J.

Other than replacing parts willy-nilly, have you done some basic troubleshooting when it won''t start, such as; pulling a plug, grounding it and seeing if you have a blue spark, pulling the plugs to see if they are wet with fuel, spraying the throttle body with starting fluid to see if the car will catch and run for a short time, holding the gas pedal to the floor and seing if it starts? 

I can assure you that these parts were not replaced willy-nilly as you call it. This is an intermitten problem. This car has been diagnosed twice by a veteran toyota mechanic and replacing the coil, which was cracked and done first, fuel pump, which worked intermittenly and done second, were replaced by his diagnosis. The fuel filter on the other hand was my first attempt at resolving the problem and done prior to taking it to the mechanic. Plugs were tested along with the fuel injectors, which all checked out by the mechanic.
Occassionally after the car has stopped running it has started up by holding the pedal down and that is when the sputtering and smell takes place. Since the car is fuel injected I never touch the gas pedal when I go to start the car. If the car has sat over night or for several hours it starts right up. This problem only happens when the car is warm. 

Have you checked (tried cleaning) the IAC valve.  This can cause the engine to die when placed in gear.

Does the engine RPM pick up when turning on the A/C.

Does the engine run better (if at all) if you press on the gas pedal?

I will be glad to clean it if you tell me what an IAC valve is and where it is located.
As far as the car running better with the gas peddle pressed I assume your referring to when it is sputtering during restarts after the engine has died. The answer is yes it helps, but sometimes it has died with the pedal pressed. Usually the car idles fine parked and runs fine down the road. Ocassionally it has bucked like it is starving for fuel. I have been able to keep the car running when I come to a stop by keeping the rpms up using both feet one on the gas pedal and other on the brake and putting the transmission in neutral. Maybe this information will help; when tested both coil and fuel pump before being replaced tested good and bad during different testings. When I had to have the car towed the mechanic tested the fuel pump again and it tested bad and this is the reason for replacing it. The coil had good spark at different times but was badly cracked, hince the reason it was replaced. I tested the EFI and replaced it when the continuity check was performed I had to forceably press against prong 1 to get a reading. It was a cheap item so it was replaced. As I''''''''ve stated before the car only has these problems when it is warm. I can start it up first thing in the morning let it sit in the driveway and after it warms up only then does it act up and then it only quits at low rpms (stops, take offs, parked, slow turns into the driveway, parkinglot or space...etc). It has bucked sometimes while driving down the hwy but it has never completely stopped at high rpms unless I am trying to restart it and it is already spitting and sputtering and I''''''''m applying pedal to clear it up.
As far as the rpms and the ac, I have not noticed an increase when it is turned on. I will double check though.

P.S. the mechanic I took my car to is not a flim-flam artist, he has a very good reputation and was highly recommended.

Did the "mechanic" test the engine coolant temp sensor (ECT)? It may be defective or it could have a short in the wiring. The ECT tells the computer that the engine is cold(hot) so the computer enriches the mixture for cold starts but a rich mixture when engine is warm/hot will cause the conditions you describe. It sounds like the car is flooding when hot. The reason the car may work when pedal is put to floor is that it increases the air flow to the cylinders and can help compensate for an over rich condition. Cleaning the IAC (controls idle rpm) as toyomoho suggests can''t hurt, it''s easy to do and you can DIY. Do a search on this site for IAC cleaning and you will probably see many posts. It may have been something the "mechanic" has already done?? 

Are you referring to the cold start injector time switch as the ECT? The only coolant temperature sensor or sending unit I know of is related to the temperature gauge itself. 
I did a forum search and could not find anything about cleaning the IAC valve what it is or where it is located. I looked in my Haynes repair manual and found nothing too. Sorry, so I''m still clueless.

I guess your 87 has a cold start injector (CSI) (are you sure?? What engine?), mine does not but uses the ECT senser to send a signal to ECM for rich cold start. There must be a temp sensor for the CSI (if you have one) which tells the ECM to activate it. Your temp sensor could be faulty to CSI does not shut off or it could be leaking and cause rich mixture because of that.
Here is reference to injectors as per engine:
http://www.autozone.com/az/cds/en_us/0900823d/80/15/74/e5/0900823d801574e5/repairInfoPages.htm

Here is reference to ECT: http://www.autozone.com/az/cds/en_us/0900823d/80/13/ec/3f/0900823d8013ec3f/repairInfoPages.htm

Here is reference for IAC: http://www.autozone.com/az/cds/en_us/0900823d/80/13/eb/ef/0900823d8013ebef/repairInfoPages.htm
 
Edit P.S. - Have you pulled the plugs when the car won''t start to see if they''re wet with fuel?

First I would like to say thanks to those who have replied to my post. However, my problem is still unresolved. I believe everyone is missing something. The problem has been diagnosed by singular sensors or shorts in the wiring directed at a singular part. Remeber the coil was replaced because it was tested good and bad during different tests and was replaced on its physical appearance (visible cracks), but left the car with the same symptoms. The fuel pump was replaced because it tested good and bad during seperate tests as well. Is there a single device, module, or sensor that could cause this type of intermitten problem with more than one component? Maybe the ECU? What do you think, let me know.

P.S. still have not located and cleaned the IAC. The cold start injector time switch tested good. This is a 1987, 2.0 4 cylinder 3S-FE, automatic Camry.