2000 Corolla 1.4VVTI Misfiring When Cold

[catha79]

Hi,

My 2000 1.4vvti is giving me some trouble the last while. When I drive it at first (on a cold engine) it misfires for the first 2-4 mins while the engine warms up.

It's generally worse if you push the accelerator down further.

So far I've changed the spark plugs, oil, air filter and also clean the MAF sensor this week. The problem seems to be getting worse.

I also think it's down on power.

Does anyone have any ideas?

Thank you.

 

[Donabed Kopoian]

Check the spark plug wires for wear, if you have a distributor, check the cap and rotor or wear.

Anothet thing might be a broken idle air control solenoid, but it would have to have a large break in it to cause that condition. Don't replace anything without checking it first and verifying that as the issue.

 

[Scott O'Kashan]

catha79 - Any updates?

 

[catha79]

Other than the problem getting worse no. Yesterday I bought a can of Holt EGR and Carb cleaner which specifically mentions to use for MAF sensors. The one I previously uses was just an electronic contact cleaner. I found out at an auto parts dealer that I shouldn't have used that one.

I'll try the new stuff this evening if I get time.

Its driving me nuts lately.

 

[Scott O'Kashan]

Sorry to hear that. Car problems can be a pain in the katoosh.

Is the check engine light on?

 

[catha79]

Hi Scott.

No the engine light never comes on.

 

[Scott O'Kashan]

Take your Corolla to an Advance Auto Parts or Autozone and they will scan the onboard computer for you for free. Write down any trouble codes they find. The check engine light doesn't have to be on for trouble codes to be stored in the computer.

 

[Donabed Kopoian]

Did you check the wires yet?

It might not be a bad idea to resistance check the coils as well. There could be something happening there that causes a miss when cold but then when the coils warm up, they function properly.

 

[catha79]

Take your Corolla to an Advance Auto Parts or Autozone and they will scan the onboard computer for you for free. Write down any trouble codes they find. The check engine light doesn't have to be on for trouble codes to be stored in the computer.

Hi Scott,

I don't live in the USA so don't have these places available. I did have the codes checked a couple of months ago but nothing came up.

Thanks

Cathal

 

[catha79]

Did you check the wires yet?

It might not be a bad idea to resistance check the coils as well. There could be something happening there that causes a miss when cold but then when the coils warm up, they function properly.

Hi Donabed,

I'll try checking over everything again this weekend. Gonna drop it to my mechanic if I can't figure it out after that.

Strangely enough though, I added some Fully Synthetic (bought this by mistake instead of semi-synthetic) oil a couple of days ago as it was low on oil again and it has improved slightly.

Wonder if that has something to do with it?

Cathal

 

[Scott O'Kashan]

Oil wont have anything to do with the problem the car is having.

You're smart to go with a full synthetic oil instead of a pretened-it's-a-synthetic semi-synthetic oil, which can have as little as 1% synthetic oil in the blend and still be called a semi-synthetic oil.

Adding petroleum oil to a synthetic oil only serves to reduce the performance and protection the synthetic oil provides the engine.

 

[catha79]

Hi All,

I got the problem sorted. I brought it to my mechanic and it turned out to be a faulty fuel injector.

He replaced it and the car is running smoothly again. All for the no-so-pricely sum of €50 including the part.

Happy out.

Cathal

 

[Scott O'Kashan]

Glad you were able to get the problem fixed.