[SOLVED] Prizm/Corolla stall problem

NOTE: Since Prizm 1990 is nearly identical to Corolla, Hence this posting in this newsgroup

Hello,

This is for a 1990 Prizm (Automatic, EFI). A few days back, started car, went for a couple of miles (first on city streets and then a mile on the highway). Stopped in traffic and could feel the power cutting off. However, traffic cleared that very second and I hit the accelerator and that was it. Drove for about 35 miles without any problem (25 on highway and 10 on city streets).

Next day, started car in the morning, went for a couple of miles (city street). Stopped at light and car just stalled. Tried to start but it wouldn't start. Let it cool for 45 minutes and then no problem. It started without any problem and runs great. It's been 3 days no problem. But yesterday the same thing happened when I stopped at a light.

What could possibly be wrong - my first inclination was fuel pump or ignition. However, if one of these parts is bad (or going bad) will they not exhibit symptoms all the time instead of intermittent problems that is in my case?

Thanks a bunch for your help.

Reply to
NKaufman
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Yes, a bad fuel pump or ignition system will usually exhibit symptoms all the time instead of intermittently.

There are quite a few things that can cause the stalling problem.

An EGR valve that is stuck in the open position could cause stalling problems. You can try lightly tapping the EGR valve and see if the problem clears up.

Also check for a vacuum leak; leaks, holes, cracks, or gaps in the black plastic snorkel between the air filter housing and the throttle body; idle air control valve; check the air filter to make sure it is not clogged; check the air flow sensor; and check the coolant temperature sender.

If all those things check out OK, check the spark plugs and ignition wires, coil, distributor, fuel pressure, and injectors.

Reply to
Ray O

Follow Ray's advice, and in addition, try driving the car with the O/D (overdrive switch if equipped) off. You may be experiencing a bad transmission shift (lock up) solonoid. Does it only stall when at operating temperature? You mentioned that you let it cool down and then it worked fine. The vehicle should not not shift into O/D until at operating temp (closed loop) and that's when your problem may begin. Just a thought. I've repaired such a problem on several vehicles.

Reply to
user

Thanks Ray, will do and post here what i find.

Reply to
NKaufman

It stalls within the first 2-3 miles of driving when I am stopped (either at a light or in traffic). After that it runs fine. So I guess you could say that it stops the first time it reaches operating temp (does that sound right?).

Thanks

Reply to
NKaufman

Does the temp gauge if equipped indicate in the "normal" range when you have problems? Is the "check engine" light illuminated or has it in the past and now ok? Try my suggestion of driving it with the O/D off and see if that makes any difference. Ignition coils have been known to fail when hot and then work fine again when cooler. Maybe you could check for spark when you are having this problem. This is a difficult problem to diagnose on the news group so more investigation and information is all to the better.

Reply to
user

Temp gauge is always in normal range. Yes, the check engine light does come up when it stalls completely. I do not think my model (Base Prizm) has OverDrive.

If ignition fails when hot and works when cold, then that does not apply to me. In my case, car stalls while getting hot, but once it engine is hot, then it runs fine. It is only the first few miles that is a problem.

Reply to
NKaufman

Do you always have to wait 45 minutes before it will start again? Check the fuel cap vent for proper operation. If you can, check for spark when the car has stalled. That may eliminate the ignition if you have good spark, leading you to check emissions components such as Ray mentioned and the fuel system.

Reply to
user

The OD switch does not prevent torque converter lockup; it only prevents shifting into OD.

Reply to
Ray O

Ray, do you mean that a Corolla has additional gear beyond third? Usually the T/C lockup is overdrive. The T/C will not lock up in first or second gear and only in third gear when operating temp (closed loop) is reached, a specified rpm (usually depending on engine horsepower), and the O/D switch is made. It's kind of a poor man's overdrive gear, without using another gear. It just makes the drive as efficient as possible. I have run into cars where the O/D solenoid fails engaged and when you come to a stop (off ramp from interstate speeds to stop), the engine will stall because the stall speed margin of the T/C is no longer available. The only solutions in that case is to run the car in second (not practical), disconnect the solenoid so it never locks the T/C, or repair the solenoid. Maybe the Corolla is a different design.

Reply to
user

I forget which model years, but for a while, the base model Corolla had a

1.6 liter engine and a 3 speed automatic while other trim levels had a 1.8 liter engine and 4 speed (gear ranges) overdrive transmissions. IIRC, the 3 speed was not electronically controlled and did not have a lockup torque converter, while the 4 speed was an electronically controlled transmission with a lockup TC. IIRC, the "shift" sequence was 1-2; 2-3; 3-lockup; unlock-3-4; 4-lockup. Touching the brake pedal was one of the signals to the transmission ECU to unlock the TC, and you could see the tach needle move up about a needle's width when you tapped the brakes enough to close the brake light switch circuit.

If the OP's car has a locking torque converter, a bad TC lockup solenoid is a possible cause of the stalling, although I have never run across a bad one.

Reply to
Ray O

Hello,

My mechanic took a look and he has changed the fuel filter and cleaned up a part that he said acted as a "choke". Lets see what happens.

--begin-----------------------------

1990-1992 Geo Prizm Reliability Trouble Spots ...have scoured repair bulletins and questioned mechanics to search for commonly occurring problems for a particular vehicle. In some cases we also give possible manufacturer-suggested solutions. In many instances these trouble spots are Technical Service Bulletins posted by the manufacturer, however, we have our own expert looking at additional vehicle problems.

Audio system: The radio/cassette player may have been built with a capacitor installed wrong causing a key-off battery drain. (1990)

Cold-starting problems: Cars equipped with the 1.6-liter engine may hesitate or stall on hard acceleration when cold because of a problem with the engine control computer. (1990-92)

Engine misfire: GM will replace the manifold absolute pressure sensor and its wiring harness on cars that surge or buck at speeds above 45 mph. (1990)

-----------------end of article----------

has anyone seen this?

Reply to
NKaufman

A bad or clogged fuel filter is more likely to cause drivability problems at higher engine speeds than at idle, and there is no choke on a fuel injected engine so unfortunately, it is highly unlikely that your mechanic fixed the problem.

I would find a shop with an ASE certified automotive technician to properly diagnose the car, or check the stuff I suggested before, or take it to a Toyota or Chevy dealer.

Reply to
Ray O

Hello,

Mechanic checked for vacuum leak and nothing.

After some more testing he figures it is the distributor. He tells me that the distributor has all sensors for this car. Is that correct?

thanks,

Reply to
NKaufman

What procedure did your mechanic use to check for vacuum leaks?

I do not understand what you mean when you say that the "distributor has all sensors for this car" because it does not make sense.

I will re-post my previous advice:

I would find a shop with an ASE certified automotive technician to properly diagnose the car, or check the stuff I suggested before, or take it to a Toyota or Chevy dealer.

The person you are taking your car to may charge a lower hourly rate than at an ASE certified shop or a dealer, but if they do not know what they are doing, you are paying them good money to take wild guesses.

Reply to
Ray O

Hello,

What method should he have used to test vacuum leak? The reason I'm asking is so I can ask him why he used method B if method A is the correct one. Right now, I have no clue about the different methods to test vacuum leak and hence will not be able to question him further.

Mechanic is ASE certified and runs a full garage with 4 mechanics (incl himself) and also does safety/emissions testing for state of VA. Further, he is a good family friend and that makes it very difficult to take the car somewhere else. However, this also enables me to question him a bit and throw some ideas without having to worry about whether he'll get upset at the questions.

I did ask him about distributor, he said that the Prizm distributor had various sensors within it. But I asked him why this problem would happen only at during the first 1-2 miles and when car is stopped. he did check one thing when the car had stopped and was not starting. he said there is no spark.

I know you are trying to help and I really appreciate that.

Now, we can replicate this problem every morning and evening (when car has been sitting either on driveway or garage at work) only during the first 2 miles. If I am stopped at light or traffic at the instant when engine decides to die, that's it. I have to let it cool for 10 min and then it runs fine. No hesitation, no problem.

Thanks,

Reply to
NKaufman

I'm not Ray, but I'll take an Educated Guess stab at diagnosis:

The symptom of "It stumbles and dies when cold, but after running a few minutes it's fine" sounds like a vacuum leak on one of the "cold start" circuits that is shut off after the coolant gets close to operating temperature. When the Thermostatic Vacuum Switching Valve (TVSV) on the culprit vacuum circuit warms up and closes, the problem goes away.

And this will be worse at idle when the vacuum leak is a larger percentage of the total intake air for idling.

There are several ways to find a manifold vacuum leak - most common is The Good Ol' Unlit Propane Torch. A vacuum leak causes a lean condition, but if the leak sucks in a propane/air mixture that 'fixes' the lean condition the engine immediately smooths out and speeds up. (Allow 1-2 seconds lag to suck the propane through the hoses.)

Having the EGR valve opening when cold and/or when idling will do this too.

I'll bet you aren't letting it COOL as allowing convection to spread the warmth you were starting to generate in the cooling system from the cylinder walls and WARMS UP the TVSV on the intake manifold. The TVSV closes, and when you try the restart in 5 - 10 minutes the vacuum leak has been shut off and it runs right.

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Reply to
Bruce L. Bergman

I have a 1986 with 3-speed automatic, the A131L, and it definitely has a lock-up torque converter, according to the factory manual and the slight bump I feel when I accelerate. But how does it work? I don't see any electrical connections for a lock-up magnet.

Reply to
larry moe 'n curly

There are dozens of different ASE certifications, and I'm pretty sure that the Pep Boys ASE-certified mechanic who tried to fix my hesitation problem a few years ago was not certified in the area of fuel systems. ;)

AutoZone.com has repair information and diagrams online for several vehicles. Here's a diagram of the 1990 Corolla distributor:

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I'm no expert, but the only sensor I see is the magnetic pickup.

Have you tried posting at

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?

Reply to
larry moe 'n curly

Bruce Bergman's advice is, as usual, excellent. The only additional advice I have to add is that the proper method to check for vacuum leaks is with a vacuum gauge. While a torch will detect the presence of a leak, a vacuum gauge will show quantitative results, and any self-respecting automotive shop should have a gauge on hand.

The Thermal Vacuum Switching Valves (TVSV) that Bruce desribed have plastic bodies, and I've seen them crack and leak when cold, but as they warm up, the leaks seal themselves up. A vacuum gauge would how the vacuum gradually rising with engine temperature.

The National Institute for Automotive Service Excellence has 8 different automotive technician tests. Someone who has passed all 8 tests is an ASE Master Technician. Hopefully, the person working on your car has passed at least the Engine Repair, Engine Performance, and Electrical/Electronic Systems tests. If you are curious, go to asecert.org and look at the practice questions. There are plenty of excellent technicians who are not ASE certified, but IMO, an ASE certification is the easiest way for a non-technical cocsumer to determine whether a technician is knowledgeable. While I had the ASE and Toyota Master Tech certification at one time, I let them lapse since I have not worked for Toyota for some time.

It has been a long time since I have looked at a Corolla, but I can only recall one sensor in the distributor - the reluctor that senses the position of the rotor, and I have never seen one fail sporadically. They tend to work all the time or not work all the time. The same is true of the igniter, as long as nobody has messed with it or the wires.

Under those conditions, I would check EGR valve operation first to make sure it is not opening at idle, either due to carbon buildup inside the valve or due to a vacuum leak.

As far as the no-spark condition, how many miles are on the timing belt? Did your mechanic check the ignition coil's primary and secondary circuits when there is no spark? How old are the spark plug wires and what brand are they? If they are more than 5 years old or have more than 60K miles, replace the spark plug wires and spark plugs with OEM parts.

Reply to
Ray O

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