when you mention the car stalls out and wont start again, does the motor crank and doesnt fire? does the starter not even attempt to turn? weather-wise, happen to notice if this happens more frequently when it's raining or high humidity?

 

The motor cranks but doesn't fire.

I have not noticed any connection between the weather and this issue

 

Have you tried pushing on the gas pedal a tiny bit when its cranking but wont start?

 

Are both your grounds good? I was recently watching a TV show where the expert said that when there are electrical problems the first place to start is to check the grounds. You have two. One going to the engine and one to the body.

 

next time this happens, pull out a plug and ground it to see if you have a spark when cranking. if there is spark, pull the intake hose off the throttle body and spray in some starter fluid to see it that makes the motor sputter. im wondering if this could be fuel pump related.

 

Replace the engine coolant temp sensor. That's 1 problem fixed, but you have another, the ignition coil assuming this is a 4 cyl model.
If it's a V6, from my experience on '94 models, it's time for a new ECM.
As always, I recommend Toyota parts.

 

Thank you soo much for your answer... if you don't mind, would you be able to explain to me a little how these parts are causing my issue?

Also, how big of a job is it to replace these parts, if I was to do it myself?

 

 

I was unable to find a vacuum leak. On a recommendation from another forum, I disconnected the EGR valve from its electrical harness... however, since the problem is intermittent, it is hard to test... how long can I run the vehicle with the EGR valve unplugged?

 

I have read user's comments on this forum which say that if you don't live in California (which I do not) that you can remove the EGR valve entirely.. is this possible? If so, how? It seems like eliminating this system entirely would make troubleshooting a little simpler.

Also, I would have thought that unplugging the wiring harness for the EGR would cause my check engine light to come on, but I drove it for about a half hour that way and nothing showed up.. is that weird?

 

"The Issue: My car will randomly stall out when I am stopped at a red light and will occasionally ride a bit rough while I am driving. When the car stalls out, sometimes it will start back up right away, while other times it will not want to start and take some time to get going again."

A couple years ago, I had this same exact problem with my 93 I4. We replaced this and that. A bunch of new parts and new cleaners. But still we couldn't solve it. First time, car died at a red light, cranked, but wouldn't fire. After the new parts, it would crank, fire, but wouldn't last past 2 blocks before it stalled out. Rinse and repeat. (F Bombs.)

So one day, as I taking things apart for a 10th look...went to put the rotor back on, but I cracked the rotor housing. (F bombs.) Went to Autozone. The size of the rotor metal was like night and day. Installed it, and haven't had a problem since. Sometimes you get lucky.

I know you said you have done a tune-up already. Just throwing this out there.

 

Replace the engine coolant temp sensor. That's 1 problem fixed

Why does that solve a problem? Not doubting, just curious.

Squirting starting fluid is a good idea. This will narrow it down for when you start buying parts. I don't think you need to pull a plug, though. It's either spark or fuel. If it's a spark problem it won't fire. If it's a fuel problem it will.

What was the logic behind the EGR suggestion? I think you did that because it was cheap.

ECM and ignition coil sound like the most likely suggestions.

If it's spark, what else could it be?

pickup coil.
ignition module.
primary wiring.

Assuming you replaced cap and rotor when you did the tune-up.

 

A bad ECT sensor can go intermittently open circuit and cause fuel enrichment which thinks the engine is cold on a hot engine. Basically floods it out and stalls.

 

Minor correction. The circuit won't read "open", as this would cause the CEL to come on or flash when it read open (as if you disconnected the sensor wires).

Mind you, if the problem goes away with the sensor disconnected, then it's the ECT sensor. When disconnected, the CEL will come on, but the ECM is programmed, that if the ECT is disconnected/no signal, it will run as if the engine is at normal operating temperature.

 

but you have another, the ignition coil assuming this is a 4 cyl model

Why do you think it's a dual problem? Are these both "it's time" kind of things with similar MO's that are hard to diagnose because they are intermittent?

 

We still don't know what kind of engine we're working on here. Once we find out, we'll discuss it further.

 

To clarify, the engine in question is the 4cyl.

Ever since I disconnected the EGR valve from its electrical harness, I have not experienced the stall out problem again, however, that could just be incidental.

Should I, if the issue comes back, unplug the ECM and see what that does?

As you can tell, my troubleshooting approach is to start with things that are entirely free to try, haha.

 

I'd like to know what OP disconnected. (this is where pics really help). The only VSV for EGR is way under the intake, UNLESS this is a Calif spec 5SF-E
It appears the problem is still there and by disconnecting whatever has created this code. Therefor, I go back to my original suggestions of replacing the ECT sensor, (easy and cheap) then if that doesn't work, pull the vacuum supply to EGR and see if that changes things.
To check codes jump E1 and TE1 in the DLC under the hood and watch for CEL blinks. Use a paper clip for a jumper.

 

Thank you for getting back with us. Each motor in these models have the "each their own" kind of problems on stalling issues and it really helps to know while posting your concern what we're trying to diagnose here.
You might have nailed it. (let's hope) The EGR sticking and stalling is a very common thing. My test is to just simpley removed the vacuum line going to it and plug it, then go for a drive at cruise speeds for a while. But sometimes, it's just a once in a while thing and hard to nail it down.
These EGR's are very robust so you can remove them and clean them and all the egr ports in the manifold. The diaphragm should be checked in the valve to hold vacuum.
So since you're on a free kick, get your hands dirty and give it a try.
BTW, leave the ECM alone. It's not the area you need to go in.

 

Not too off-topic, I hope.

Any ideas on why water-injection was never used on production cars?

On misty days my 72 Ford F250 w/360 motor used to act like it was on catnip. Peppy and smooth as silk.

Water can be used to blast-clean combustion chambers -- rev the motor and trickle into intake air stream.

Mild use of water would keep valves, pistions and chambers clean.

And cool and regulate the combustion flame.

Perhaps some drawbacks I'm not aware of.

Context here is, water always seemed like it would have been a better alternative to recycling exhaust gas.

 

The EGR sticking and stalling is a very common thing.

I can see how this would explain stalling, but not the dead-for-minutes, hours or days thing.

The thing with the battery and alternator make me think it's something electrical like coil.

 

After reading this I think resetting the ECU replacing the battery had an impact on performance. As the car re-learned, performance degraded.

Please answer the following:
What exactly were the tuneup actions performed?
What is your gas mileage?
Does this happen only when warm?
How often do you change the oil and with what brand and weight?
Do you use fuel system cleaners, if so, what kind?
How often do you change your coolant and with what brand?

 

Here's something easy to do:

If it happens again and won't start.

Turn ignition key to ON but don't crank motor.

Is the engine warning light on?

Not the charging light.

I don't know exactly what the name is under the light.

If the light does NOT come on then you can suspect the ECM is causing the problem.

If it DOES come on, I don't think you can rule out the ECM -- you simply haven't narrowed it down.

But, as I said before.

On a no-start, I would start with a simple squirt of starting fluid into the air filter housing.

And check for the warning light.

 

Well.. I though it might have been fixed with the EGR valve unplugged thing... but unfortunately, I just ran out to get a soda and the car started up super rough (from cold start) and then stalled out... I started it back up and drove down the road, when I came to a stop, the check engine light came on (for the first time that I can ever remember) but the car didn't stall again... when I started moving again, the check engine light went off.. this happened twice, then the car ran okay.

Any thoughts?

 

check engine light came on (for the first time that I can ever remember)

Power of suggestion!

Now you have a code to check for. This might tell you something. (Actually, we should have suggested checking codes before this since it's likely you already had them.)

I don't have a scanner, so when I need codes read I take my car to Advance Auto Parts. Generally, auto parts stores will read your codes for free. Good for business.

Except in California, where they've outlawed the practice -- believe it or not. Probably had an environmental excuse.

You COULD read the codes out yourself by shorting the right pins on a special connector in your car and counting the flashes of the warning light, but it's a lot easier, for you and me, taking your car to the parts store.

Suspense builds...

 

I just did some checking and it turns out your car is OBD2:

BTW, your car is the 1st year Toyota used OBD2. And one of the 1st cars in the US to have it. You have the NEW technology. You just need an OBD2 reader to read the CEL. Most people (even auto places) think the '94 Camry has OBD1, but they are wrong.

http://www.toyotanation.com/forum/103-3rd-4th-generation-1992-1996-1997-2001/263109-1994-camry-v6-check-engine-light.html

This is a major advantage getting diagnostic info from the computer.

Since it's a pre-1996 car the parts store guy might think it's OBD1. Make sure you let him know.

And ask him for any freeze-frame data. Some scanners have this capability. Have him jot it down if it's not too long of a list.

 

Tech1984 is probably right about you causing the codes by unplugging whatever. Since you didn't have the light before and now you do. Still won't hurt to check the codes.

Looks like he also doesn't take me seriously about your car being OBD2. He's probably right. Considering...

And a correction: If flooding is causing the no start, the starting fluid spray test is invalid. So, a definitive spark test could be helpful.

If you get the hard-to-start condition, you might try using the "clear flood mode" while cranking. Holding the gas pedal ALL THE WAY TO THE FLOOR tells the ECM to close the injectors and provides more air for burning/clearing the gas in the cylinders.

 

I'd like to offer some advice, but can't until the questions I asked are answered. Otherwise its guessing, unplugging things which possibly creating more problems.

I have a brushing your teeth vs pulling them out later mindset..:hi: