Corolla 2000, P0171 And Starting Problems

Hi people

As the title says, I'm experiencing some problems with my 2000 Corolla.

Every time I step on the gas, I hear a strange noise coming from the engine.. In spanish we say "pistoning", and it basically happens when the fuel is not being burnt properly and/or the "combustion" is not happening the way it should (that's what It could be, I'm not sure)

Another strange thing is: when idle, a small whistle sound comes from under the hood.

I believe those two problems above are related to the P0171 code. I've tried putting a plastic and covering part of the air intake to balance the mixture, but the code shows up again.

And also, I think not related to the code, I'm having some starting problems. Cold starts are normal and usually good, but when the car was used and the engine has been stopped for about 30min - 1 hour, I have to crank it way too much before it even tries to start.

Any ideas?

Thank you !

some info:

137K miles

28 MPG

No modifications

No recent changes other than tires

I use Castrol 10W-30

Sounds like you are describing "piston slap" or "spark knock". Can lead to rough idle, poor fuel economy, the noise you are hearing, hesitation on acceleration, and loss of engine power.

Can happen on these engines, some are worse that others. Can be described as a dull pinging or metallic clunking sort of noise that is keyed to engine revolutions. Can be caused by a number of things. Since you have a 2000 Corolla - your 1ZZ-FE has VVT-i - that system can get stuck with the wrong valve overlap causing this piston slapping. Can also be caused by excessive clearances in the piston/piston walls. excessive carbon build up inside the combustion chambers, faulty injectors, oiling issues (oil consumption), vacuum leaks, induction system issues, faulty upstream O2 sensor, faulty MAF sensor, clogged cat, etc.

Need to diagnose this a little more - as it could be almost anything now. P0171 is likely the result of the issue - hearing a whistling sound at idle could be related - hard to start when warm is also possibly related. Covering the intake to "richen" up the mixture will not work with this engine or most modern engines - it will just adjust around the obstruction by varying the duty cycle to the injectors. Better to run a datalogging scanner to the car - see what codes are on the ECM, see if there are anything pending, and see if you can grab some data on the STFL and LTFL (short term fuel trim/long term fuel trim).

Might be worthwhile to pull the sparkplugs and see how they look like. If they are heavily worn or have excessive deposits on them - could be the cause of your issues. Definitely the least expensive check/replace at this point.

Quality of gas has a huge influence on how the car runs. Might try running a good quality fuel system cleaner + higher octane gasoline. The higher octane will resist pre-detonation, especially from excessive deposits inside the combustion chamber. If the sparkplugs are not the cause and the higher octane helps - could just be deposits inside the engine. That point - the amount of deposits and their composition will determine how to treat that issue. Basically, need to clean the induction system (intake manifold, throttle body) and inside the combustion chambers (valves, top of pistons, etc).

VVT-i issues are pretty common - the oil control valve (OCV) and the oil control valve filter can be easily clogged - causing valve timing/overlap issues. As this system is a variable valve timing system driven by an actuator and oil pressure - if the oil cannot get to where it needs to go, valve timing will be off. One check is to disconnect the OCV electrical connection and see if the engine stumbles or not. If it runs poorly, it is working correctly, if it doesn't seem to change - then you need to do some more diagnostics.

Vacuum leaks are very common and should be one of the first things you check. Check every vacuum line, hose union, hose tees, in around about the intake manifold, valve cover, and throttle body. Check the PCV valve and the associated hose. Check around the injectors for fuel leaks, check that the coil on plug igniters are in good condition/no cracks, check for exhaust leaks, check chassis ground points.

Battery been replaced recently? If this still has the original battery - could be time for a new one. A battery can be still strong enough to turn the engine over but not provide enough reserve battery power to feed all the electrical systems under certain conditions. Voltage fluctuations and electrical noise can cause the ECM to get confused - corrupt signals. Can cause all sorts of issues that can be hard to diagnose.

First of all, thank you very much for your time.

The sparkplugs are brand new, I changed them 3 month ago and codes P0300 and P130X (x3) "cylinder misfire" disappeared. So I believe they are still fine.

A week after I bought the car, and after noticing some noises, I tried 93 octane gas and I definitively felt it much smoother and more powerful. Been using it since then.

It is not the original battery, but I don't know how old it is.

Where do you suggest me to start??

Thank you very much

If the higher octane helped with the noise - sounds like the car is pretty dirty internally. With that mileage and age - having heavy deposits inside the combustion chambers is not unusual.

Try the simple things first - get a quality fuel system cleaner, add that to your tank with fresh gasoline. Try to pick a fuel system cleaner that has the PEA additive (might find cleaners that list PIB (polyisobutane, PIBA (polyisobutane amine), or PEA (polyetheramine)) - all will work, but they run from good to best - PIB=good, PIBA=better, PEA=best.

Redline Si-1 fuel system cleaner has the most PEA of the ones that I know of, Chevron Techron Concentrate Plus fuel system cleaner has quite a bit (actually twice the PEA compared to their less expensive Chevron Techron fuel "injector" cleaner), Gumout with Regane has a fair amount of cleaner, Valvoline Synpower fuel system cleaner is touted to have some PEA.

See if that helps with the knocking issue. If it doesn't change or gets worse - then you'll have to do a little more diagnostic work and try and localize the sound.

Just bought Red Line SI-1 on Amazon. Should be here this saturday.

Do I put when the tank is empty or full?

Thank you,

Add it to a tank that is low - at least 1/2 way empty - that way you can pour in the entire contents, then top off the tank with fresh gas. You want to make sure you mix it up well with the gas - so do not add to a full tank and do not try and run it at a higher concentration. Read the instructions on the bottle - it will give you an idea of the mix ratio.

Add it to a tank that is low - at least 1/2 way empty - that way you can pour in the entire contents, then top off the tank with fresh gas. You want to make sure you mix it up well with the gas - so do not add to a full tank and do not try and run it at a higher concentration. Read the instructions on the bottle - it will give you an idea of the mix ratio.

Great.. I will.

I'd like to add something.

One of friends (talking about the starting problems when warm) told me to spray some Starting Fluid to the air intake and passing through the MAF. I did it, and the car started after cranking for no more than a second.

Does this mean that I do have some fuel delivery problem?

Thank you

EDIT:

To clarify the whistle sound, I recorded a short video.. Pay attention to the high pitch sound in the background

https://www.dropbox.com/s/ec0mkog12unjje0/20131010_231044.mp4

The fuel system is a returnless, on demand system. This means that fuel is only delivered when needed to help reduce maintenance (fuel is only filtered when needed, not constantly circulated like before) and improve evaporative emissions. Drawback is, that the system has a slight latency in fuel - the engine will crank a couple of revolutions before it will fire.

You issue could be related to a fuel issue - hard to say without more diagnostic work. Could be a vapor lock - common on carburated cars, fuel running to the fuel rail may be vaporizing before it hits the injectors. They are only designed to run liquid, so the fuel pump has to keep pumping fuel up there to cool things down to the point that the injectors can get liquid fuel.

Could also be an ignition issue. If this fuel system cleaner doesn't work - when you get to that point of excessive cranking - stop before it catches and pull the sparkplugs. Want to see if they plug ends are wet with fuel or dry. That will tell you: dry = fuel issue, wet = ignition issue.

The fuel system is a returnless, on demand system. This means that fuel is only delivered when needed to help reduce maintenance (fuel is only filtered when needed, not constantly circulated like before) and improve evaporative emissions. Drawback is, that the system has a slight latency in fuel - the engine will crank a couple of revolutions before it will fire.

You issue could be related to a fuel issue - hard to say without more diagnostic work. Could be a vapor lock - common on carburated cars, fuel running to the fuel rail may be vaporizing before it hits the injectors. They are only designed to run liquid, so the fuel pump has to keep pumping fuel up there to cool things down to the point that the injectors can get liquid fuel.

Could also be an ignition issue. If this fuel system cleaner doesn't work - when you get to that point of excessive cranking - stop before it catches and pull the sparkplugs. Want to see if they plug ends are wet with fuel or dry. That will tell you: dry = fuel issue, wet = ignition issue.

Cool! Will report back after the Fuel Cleaner.

About the sound, did you have the chance to look at the video?

I really appreciate your help

Thank you,

Fede.

Hard to tell from the vid - lots of other background noise, but you can definitely hear a high pitched whistle there. To me, that sounds like an induction whistle - could be a leak in the airbox or the tubing running to the throttlebody. Have to check all around and pull it apart - as sometimes you can get cracks in between the pleats on the airbox tubing.

The 1ZZ-FE engine is pretty noisy to begin with - so it can be tough to diagnose these sounds.

Have you noticed if the sound got better or worse or stayed the same, once the engine gets warmed up?

Hard to tell from the vid - lots of other background noise, but you can definitely hear a high pitched whistle there. To me, that sounds like an induction whistle - could be a leak in the airbox or the tubing running to the throttlebody. Have to check all around and pull it apart - as sometimes you can get cracks in between the pleats on the airbox tubing.

The 1ZZ-FE engine is pretty noisy to begin with - so it can be tough to diagnose these sounds.

Have you noticed if the sound got better or worse or stayed the same, once the engine gets warmed up?

I got Red Line cleaner today. Added it and then filled the tank with 93 octane.

Will drive around tomorrow and let it work.

About the sound, it stays the same.

Looking around, I found this YouTube video. Sounds like my car http://www.youtube.com/watch?v=yldykQZd2S8

Apparently this guy fixed it .. This is what he said:

I took the intake box out and removed the throttle body. Removed IAC valve as well. Throttle plate was dirty, as well as the IAC valve. Cleaned both with tooth brush, carb cleaner, and Seafoam spray can. Installed new OEM gaskets for IAC and TB part number(s)22215-74400

 

22271-0D020

I just saw your tutorial to clean the TB, and it doesn't seem so hard. What about those gaskets? I couldn't find them on amazon.

Gaskets looks like an o-ring - if you are careful, you can reuse them. Better to replace them, as if they could be a potential source for a vacuum leak. I've been able to clean the throttlebody pretty well with it still attached to the intake manifold. But to do a really good job, have to pull it off.

Gaskets looks like an o-ring - if you are careful, you can reuse them. Better to replace them, as if they could be a potential source for a vacuum leak. I've been able to clean the throttlebody pretty well with it still attached to the intake manifold. But to do a really good job, have to pull it off.

is it difficult? from 1 - 10

I love DIY, and I'm willing to do anything as long as I can still use my car the following morning

I'd say this is about a 5 on that scale - 1 being simple. no tools needed and 10 being down to rebuilding the engine. Not to say it is difficult - its the screws on the IAC that will be a pain. Not standard torx drives - they are 5 pointed screw heads. You could jam a slightly smaller torx or even a small flathead in there to get them loose, but usually ends up destroying the head of the screw. Many opted to replace them with more common hardware, after they removed the IAC valve.

If this is your first experience with cleaning the TB - do it with it still attached to the intake manifold. You'll get 80% of the gum and varnish this way. If it still is causing issues - then you know it is something related to the bleed air (siphons air in when the throttle plate is closed) or IAC valve. Those can get completely clogged with gum and carbon deposits - have to pull the TB to get at them at that point. I'd try the least resistance method first - if that doesn't work - then pull the TB.

I'd say this is about a 5 on that scale - 1 being simple. no tools needed and 10 being down to rebuilding the engine. Not to say it is difficult - its the screws on the IAC that will be a pain. Not standard torx drives - they are 5 pointed screw heads. You could jam a slightly smaller torx or even a small flathead in there to get them loose, but usually ends up destroying the head of the screw. Many opted to replace them with more common hardware, after they removed the IAC valve.

If this is your first experience with cleaning the TB - do it with it still attached to the intake manifold. You'll get 80% of the gum and varnish this way. If it still is causing issues - then you know it is something related to the bleed air (siphons air in when the throttle plate is closed) or IAC valve. Those can get completely clogged with gum and carbon deposits - have to pull the TB to get at them at that point. I'd try the least resistance method first - if that doesn't work - then pull the TB.

Ok, so here I am reporting back as I promised.

The tank is almost empty. Today I got back home with 270 miles since my last refill. I bought a second bottle of Red Line to do the "Full treatment".. I'll be adding it tomorrow.

The "pinging" problem seems to have stopped (or at least decreased since I have not heard it again) but the starting problems persist. Today I had to stop for a few minutes to pick up some documents, and (of course warm) it took me about 20 seconds cranking before I opened the hood to spray some starting fluid in the air intake.

About the whistle when idle, I'll do as you suggested and clean the TB with it still attached.

Any ideas? I'm worried about the starter.

Thank you

There could be a vacuum leak at TB/ intake manifold gasket, vacuum/PCV hose/fittings, or the intake manifold itself... You could try locating any vacuum leaks with a cigar/joint in vacuum hose unhooked from brake booster... By the way, does it tend to stall while pumping the brakes hard and repeatedly while idling?

There could be a vacuum leak at TB/ intake manifold gasket, vacuum/PCV hose/fittings, or the intake manifold itself... You could try locating any vacuum leaks with a cigar/joint in vacuum hose unhooked from brake booster... By the way, does it tend to stall while pumping the brakes hard and repeatedly while idling?

other moment than cold start, never really noticed a tendency to stall. Will try that and report back.

There could be a vacuum leak at TB/ intake manifold gasket, vacuum/PCV hose/fittings, or the intake manifold itself... You could try locating any vacuum leaks with a cigar/joint in vacuum hose unhooked from brake booster... By the way, does it tend to stall while pumping the brakes hard and repeatedly while idling?

No, it does not tend to stall.

Ok, so your brake booster isn't leaking... You can try the smoke blown in brake booster hose test to locate you intake vacuum leak(s).

I haven't done that yet, but I'm pretty sure I have a leak because as I said when idle you can hear an annoying whistle.

A guy in another forum recommended to clean the MAF again with the battery disconnected. Now the starting issue seems to be solved!

I turned on the car and left it idling for about 10 minutes. It first started with a very rough sound, like almost stalling. I guess the ECU/ECM was 'learning' again. When I drove around the neighborhood, the first and second time I stepped on the gas the car hesitated. Few minutes later the car was accelerating properly.

Since I was in an urban area, I couldn't go faster than 40mph. I guess tomorrow when I hit the highway I'll experience the same learning behavior, right? What do you guys suggest?

I checked the codes and the P0171 was still there, and now a Cylinder 1 misfire popped up (Is it because it's still learning?). I cleaned them to see if they appear again.