Car start, then stall soon after I release switch

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95 Corolla, 200k miles, 1.6L engine with auto transmission. Last smog check a couple months ago I almost fail with high Nox, normal HC and CO, and have to pass with retest. So a couple days ago I did an EGR clean up (taken out EGR valve and EGR hose and spray with parts cleaner) and engine bay degreasing with Simple green and buckets of water. Afterward I noticed the car would start in cooler weather then quickly die down. It happens consistently for 4-8 times, the starter sounds normal as well as the first ignition, and the way it stopped sounds like I turn the engine off after a normal drive. If I hold the acceleration partly it would not stall until I let my foot off it. However if the weather hot it would start on the first try and the drives afterward is normal. I've done the commute 4 miles each way for at least 2 times already and it never stalled while driving. I'm planning on changing the fuel filter before this so I already have the part, but I am postponing it until I I figure out why it would stall. What would it possibly be?
 
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I'm confused if the stalling has started to clear up. It sounds like fuel injection systems wiring had gotten wet and caused a fuel delivery problem. You could inspect the conectors at the injectors and sensors to make sure they are secure, clean and dry. A new fuel filter and cleaning the throttle body if you haven't already would be a good idea.
 

PandaBear

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Originally Posted By: mechanicx
I'm confused if the stalling has started to clear up. It sounds like fuel injection systems wiring had gotten wet and caused a fuel delivery problem. You could inspect the conectors at the injectors and sensors to make sure they are secure, clean and dry. A new fuel filter and cleaning the throttle body if you haven't already would be a good idea.
Actually the EGR cleaning was done 4-5 days ago, not a couple days ago (sorry for the confusion). It goes away then come back, that's what confused me. The wet cleaning was done at least 4-5 days ago and the car is parked outside (dry weather with 70s-80s temperature).
 
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So does it run well if you have your foot on the gas? Sounds like your idle air bypass is plugged up.
 

PandaBear

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Originally Posted By: eljefino
So does it run well if you have your foot on the gas? Sounds like your idle air bypass is plugged up.
Yes, it would run with no problem. During lunch time I went home to check a few things. Voltage when not running is 12V after 8 crank, 13V after idle with foot on pedal for 20 second and then stall, 14.1-14.3V after running 1 minutes and the idle on its own with no foot on pedal. I sprayed some part cleaner (not carb cleaner because I only have part cleaner at home) into the idle air control valve hole, at the bottom of the throttle body butterfly, the hole on the side of the throttle body (front), on the butterfly itself, and into the intake manifold. The liquid came out black / brown with a red tint. I wipe the excess with a torn denim and the thing is black. I didn't spray a lot because I do not want to flood anything. Then I start the engine and let it idle with foot on pedal for around 30 second. Since I have no tachometer, I can only guess it is around 2k rpm. Then it stay idle ok, with the intake pipe and air box off, you can hear quite a whistle. The idle smooth out quite a lot when the engine is almost warm up. I also found an exhaust leak near the O2 sensor, the original paper gasket that came with the exhaust manifold seems to have worn out and disappeared. I'll need a soap bubble test to see if this is the case, but I do feel some air with my hand close to the exhaust manifold without heat shield.
 
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I wouldn't worry about your exhaust right now. Maybe you have a vacuum leak near your intake manifold gasket? Can you spray it with WD40 or something while it's idling? What's this "parts cleaner"? I would only be using car stuff on cars; you might get weird chemical reactions otherwise.
 

JHZR2

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Originally Posted By: eljefino
So does it run well if you have your foot on the gas? Sounds like your idle air bypass is plugged up.
+1, and/or a bad connection on the ICV. Had that on my 91 BMW.
 
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Another possibility is a malfunctioning EGR system; two key problems an EGR valve can cause are rough idle and high Nox. It's usually fairly easy to check, just unhook the hose or pipe that connects the EGR valve to the exhaust pipe and plug it up with something, then crank it and let it run just for a few seconds. If it starts idling smoothly, there you go. That's curious about the temperature differences though.. I wouldn't think temperature would affect an EGR related problem, but I can't think of what it would, either. Oh, and also, it sounds like the leak near the O2 sensor has not yet become relevant, because when they are a problem they lead to rich mixtures. Still might want to get it fixed at some point.
 
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PandaBear

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Just out of curiosity. I noticed that the fuel injectors are freely rotating around inside the intake manifold. Is it normal and does that means there's enough gap that air and water can leak in? I was pouring water around the area after the engine degreasing.
 
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The injectors have o-rings and yeah I guess they could spin. If water got in, it would have blown out by now.
 

PandaBear

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I changed the fuel filter over the weekend, the first start after the change stalled even in warm weather (70F) but this morning it start right up. Will park my car outside tonight and check again tomorrow with colder parts and air. One thing I notice is the throttle cable has some slack. I guess I can adjust it to have better accelerator pedal feel but I'm not sure if it is going to make any difference. Also I notice where the throttle cable pulley (that wheel thing where the cable grip on) rest on is a springy hard stop that is connected to a vacuum hose. What is it? and should I check / test it?
 

PandaBear

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Tried compress air in every single vacuum tube for "testing", and found water spray out between the EGR and the vacuum control valve. After that the car no longer stall in the cold when starting. Maybe not related, maybe it is the help from the new fuel filter. Someone on Toyota Nation suggests a new coolant temp sensor, but since it is no longer stalling, and there was no CEL / code for sensor, I guess I'll wait and see. Thanks guys.
 
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Originally Posted By: PandaBear
Also I notice where the throttle cable pulley (that wheel thing where the cable grip on) rest on is a springy hard stop that is connected to a vacuum hose. What is it? and should I check / test it?
It's called a "throttle opener". It's some kind emissions device. http://www.toyotalexusforum.com/toyota-camry-club/9330-1995-camry-v6-throttle-opener.html I must have lucked out; my 94 7AFE Corolla has NONE of these emissions devices - has no throttle opener nor an EGR valve/system.
 
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My sister's 94 Camry 5SFE has that throttle opener thingy. As best I can tell, it pushes the throttle open a bit with the engine off, so it has a little extra throttle during cranking, then as it starts, vacuum pulls it closed and the IAC takes over.
 

PandaBear

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Actually, I did remember cleaning some grease / oil off the throttle opener and stroke it a few times to see how it works. Maybe it got dirty and stuck closed with vacuum and isn't released / opened until I cleaned it and solve the idle issue?
 
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