2001 corolla - engine hesitates and sometimes dies - Toyota Corolla, Chevy Prizm (1998-2008)

Guest thunter

Hi,

If my 2001 Corolla (35k miles, warranty time expired) is cold, my engine sometimes stumbles and loses RPMs when I turn the car on, put it drive, and press the accellerator. Usually I can play with the gas pedal and get through this stumbling sensation,

but sometimes the vehichle does not recover and dies - at which point I can simply turn the car on again and drive normally. Once the car reaches normal operating temperature, the car runs and idles fine. Here are my observations:

1. Problem seems to occur when the engine is cold but when the outside air temp is hot. For example, I am more likely to experience this problem when I start my car after it has been sitting under the hot sun for several hours, but not in the morning when I go to work.

2. Problem normally happens when accelerating from a cold start (i.e. car has not been in operation for a few hours).

3. Problem use to occur about once every 2 weeks, now it is more frequent - it's almost daily.

4. Problem has occured twice while driving.

- the car was not warmed up yet, or if it was, it just got up to temperature.

- the car was stumbling while idle at a light.

- a lack of accelleration was felt when pressing the gas pedal.

- this continued until I was able to drive faster than idle speed.

5. Sometimes the car dies. This is what happens:

- turned the car on

- put the car in drive

- pressed the accelerator

- car died while turning out of the parking space.

(note: there seems to be a higher chance of the car dying if I'm

making a hard turn in idle speed and the AC is on).

- put the car in Park

- turned the car on

- I am able to drive normally.

6. Problem never happens while idling in the PARK gear

or driving in the REVERSE gear.

7. If the A/C is on and the ambient air temp is hot (90deg or so), I will probably experience the problem

Any help or suggestions is greatly appreciated.

Guest Traveler

Check that no vacuum hoses are off.

Similar problems can be related to bad throttle position sensor or coolant temp sensor.

A shop may be able to recover diagnostic codes that pinpoint it.

Keep a clean fuel filter in it (1000 gallons max IMHO).

Check that no vacuum hoses are off.
Similar problems can be related to bad throttle position sensor or coolant temp sensor.
A shop may be able to recover diagnostic codes that pinpoint it.
Keep a clean fuel filter in it (1000 gallons max IMHO).

I agree. The root cause is the engine computer is not properly setting the idle speed or the mixture for cold operation. How high is the cold idle? It should be close to 2000RPM. IF the throttle position sensor (TPS) is bad, it would operate poorly at all temps. Let the car warm up, in park or beutral, rev the engine rapdily, if it stumbles or hesitates, the TPS is prbably bad. Also, how old is the coolant? Is the coolant level low? Has the tranny fluid been replaced recently? is the tranny shifting smoothly?

1- Vacuum hoses

2 - ECT (Engine Coolant Temp sensor)

3 - IAT (intake air temp. sensor)

Guest clam61

this isn't related, but since u have a 2001, can i ask if you are able to fold down your rear seats?

could you also tell me which model you have, i.e. CE or whatever

Are you sure you're out of warranty? My 2003's bumper to bumper warranty is 3 year / 36000mi and the powertrain warranty is 5 year / 60000mi. Did Toyota extend the warranty coverage for the 2003's?

Did you have the car in for a tune up or 30k miles service? Was it working fine then?

SOunds more like the idle circuit or idel unit is not working properly. Also, what is the condition of your exhaust or your air filter. The fact that it stalls in Drive but not Reverse.... leads me to belive that it's not making enough power since 1st gear is taller than reverse and more likely to stall.

IF it's a major problem... you could just start by turning up the idle. There should be a set screw on the throttle body. if you back it out farther, it should raise the idle. I'd increase it about 200-300RPM. Thsi is a good short term solution I suppose.

Guest thunter

I'd like to thank everyone for the suggestions, and I do have a little more informaiton on the issue.

The warranty is in fact over. This is just a case of bad timing. I haven't had the 30k checkup yet. It was one of those things I was going to get around to doing.

As it stands, I can reproduce my problem by doing the following:

1) start car

2) in PARK, immediately rev the engine. When I mash the gas, I can feel the hesitation.

3) After a few revs, and after I'm satisfied that the car is behaving as it should, everything is fine.

This is very reminiscent of having to warmup an old car before driving it.

What I've done:

1) added some gumout stuff to the tank

2) replaced air filter

3) cleaned throttle body

4) tested the idle position sensor

5) tested the idle speed control vavle

6) inspected vacuum hoses and connections

Things to do:

7) test the MAF sensor

Things I'm hessitant to do:

8) test the fuel pump

9) test fuel pressure regulator

To clam61: The seats fold down and is an LE

What about the EGR and or PCV valve? Take a look at those. Still sound liek an air leak of some kind. Did you check the intake air temp sensor (IAT) and the Engien Coolant Temp sensor (ECT) The IAT is typically on the airbox. The ECT is usually on the thermostat or the radiator.

The fact that it runs fine when warmed up, eleiminates most itemp and should pint to something in the idle circuit or relates to the engine temp.

For the past few months we've been having the same issue with my wife's 2001 Corolla LE. It has close to 60k. Last Friday the check engine light came on so I took it in for service at a local garage. They said the code was "multiple misfires" and replaced the spark plugs. It didn't fix the problem. I got this from another member of Corollaland and am going to try and get to it tonight.

-------

(excerpt from another corolland forum member.)

my wife's car gave us a different code -- one that indicated a bad sensor by the air filter. (I'm not home now, so I don't remember the exact code, but it *wasn't* "multiple misfires.")

She did, however, get that misfire code a few months ago although the car was running fine. In that case the shop simply reset it and all was well till this new code popped up.

Here's what I'd try -- it made a HUGE difference for my wife's car, and it's cheap and easy.

1. Remove the gas cap and put it back on tightly, just in case.

2. Disconnect the negative terminal of the battery and remove the fuse that's labeled EFI. It's small and wedged between two larger fuses, but you can wiggle it out. This will reset the codes while you do the following:

3. On top of the air filter housing (slightly to the back) is a sensor. It's held onto the housing by two small screws and a wiring harness that's easily removed (squeeze and pull gently).

Remove it. On the outside you'll see a small wire with what looks like a drop of oil on it. More importantly, if you look down into the thing you'll see two tiny wires deep down, across one of the openings. They're each about 1/4 inch long; a flashlight helps.

You need to clean these wires. I used some choke cleaner I had, but any kind of alcohol-based component cleaner will do the trick. I sprayed it generously into the sensor, then I GENTLY used a Q-top to wipe those two wires, and another to clean out the inside of the sensor as well as that oil-drop thing.

Let it dry for 15 or 20 minutes, then reinstall it.

4. Replace the fuse and reconnect the battery. (Reset your clock and your radio stations. default_smile

My wife said that cleaning that sensor was "night and day" with her car -- no more check-engine light, no more hesitation.

But I stress that she had a different code, and this might not help. Still, the difference was so striking that it can't hurt. It'll take about 30 minutes, tops.

Good luck!

That did it. Once I cleanded the sensor on the air intake the car has ran great. Thank You so much!!

Jason

For the past few months we've been having the same issue with my wife's 2001 Corolla LE. It has close to 60k. Last Friday the check engine light came on so I took it in for service at a local garage. They said the code was "multiple misfires" and replaced the spark plugs. It didn't fix the problem. I got this from another member of Corollaland and am going to try and get to it tonight. -------

(excerpt from another corolland forum member.)
my wife's car gave us a different code -- one that indicated a bad sensor by the air filter. (I'm not home now, so I don't remember the exact code, but it *wasn't* "multiple misfires.")
She did, however, get that misfire code a few months ago although the car was running fine. In that case the shop simply reset it and all was well till this new code popped up.
Here's what I'd try -- it made a HUGE difference for my wife's car, and it's cheap and easy.
1. Remove the gas cap and put it back on tightly, just in case.
2. Disconnect the negative terminal of the battery and remove the fuse that's labeled EFI. It's small and wedged between two larger fuses, but you can wiggle it out. This will reset the codes while you do the following:
3. On top of the air filter housing (slightly to the back) is a sensor. It's held onto the housing by two small screws and a wiring harness that's easily removed (squeeze and pull gently).
Remove it. On the outside you'll see a small wire with what looks like a drop of oil on it. More importantly, if you look down into the thing you'll see two tiny wires deep down, across one of the openings. They're each about 1/4 inch long; a flashlight helps.
You need to clean these wires. I used some choke cleaner I had, but any kind of alcohol-based component cleaner will do the trick. I sprayed it generously into the sensor, then I GENTLY used a Q-top to wipe those two wires, and another to clean out the inside of the sensor as well as that oil-drop thing.
Let it dry for 15 or 20 minutes, then reinstall it.
4. Replace the fuse and reconnect the battery. (Reset your clock and your radio stations.
My wife said that cleaning that sensor was "night and day" with her car -- no more check-engine light, no more hesitation.
But I stress that she had a different code, and this might not help. Still, the difference was so striking that it can't hurt. It'll take about 30 minutes, tops.
Good luck!

I just wanted to add that I had the same problem on my 2001 LE at 50000 miles, and it turned out to be that sensor. I tried cleaning the two wires, but ended up replacing the part (easy DIY job)!

I highly recommend doing what jeaton posted

I was having a problem where it would idle low and sometimes stall shortly after starting, lots of hesitation in higher rpm ranges, and low gas mileage, no error codes, tried all the usual stuff and everyone I talked to had a different guess (tps, fuel filter, etc), well I stumbled on this post and decided to try it, the wires looked black when I started and shiny silver when done, it accelerates like new again and has no hesitation. haven't run a tank yet but I hope it will help the gas mileage.

my 2001 only has about 35k on it so if anybody has similar issues they should try this, it only takes a few minutes

thanks

sorry to bring up an old post, but some people seem to be having similar issues

Bikeman982

Seems like an easy enough solution to a common problem.

Clean the sensor and it will run better.

Guest anben

Thank you so much for the great info in this forum thread. My 2001 corolla was stalling when cold, and even when warmed up it has not been very good - had to feather the throttle to keep it from stumbling. The dealership was leaning towards a new engine but that didn't make sense to me or my wallet! I cleaned the MAF sensor as per the instructions in this forum, took about 20 minutes - (noted that one of the screws holding the sensor in place was not tight). The cleaning worked like a charm. Went back to the dealership and got my money back for the misguided diagnosis they gave me. Thanks again!

Thank you so much for the great info in this forum thread. My 2001 corolla was stalling when cold, and even when warmed up it has not been very good - had to feather the throttle to keep it from stumbling. The dealership was leaning towards a new engine but that didn't make sense to me or my wallet! I cleaned the MAF sensor as per the instructions in this forum, took about 20 minutes - (noted that one of the screws holding the sensor in place was not tight). The cleaning worked like a charm. Went back to the dealership and got my money back for the misguided diagnosis they gave me. Thanks again!

That's crazy! Really shows just how aweful the service is at many dealerships. I'm glad you got your money back!

Guest Bobdaboider

Seems like an easy enough solution to a common problem.

Clean the sensor and it will run better.

Yup