2009 Camry SE 2.4L (2AZ-FE). Getting negative ignition timing (IGN) and what appears to be misfires when accelerating.

 

What is the engine coolant temp reading on the scanner when engine warmed up? Timing is based in part on coolant temp.

If an ign code is pending for a cylinder, swap that coil to another cylinder and determine if the code follows the coil.

Cleaning the throttle body can result in improved idle.

 

Thanks. It is a "new" TB - pulled off a junker that had 55k on it. My OEM TB was not opening the valve, it seemed, so I thought this would have solved the issue. It was running BAD before I put in this new TB, now it is just popping and hesitating. The main prob with the pend code is I never saw it was there until I dug into the gauge, and it has not returned. I was planning on swapping the coil and see if it moved with it, but it's not throwing the pend code reliably, so ?? I'm going to check the resistance of all four coils to see if #2 is notably different.

The engine temp is in the normal range of 188 - what I have noticed it being all the time. Have yet to see it spike over 190.

 

$186 and change, and my car was at the dealer the entire day. Was there at 7:15AM, had them drive me home at 9:00 so I could take my Tacoma to work. Had them pick me up from my house at 4:30PM to go get it.

They have no idea what is wrong.

I understand that with no CELs and no stored codes it is a tough thing to figure out. But I knew the same answer $186 ago. And what really irritates me is that they didn't even scan a single sensor. Yes, you read that right. They did a system scan, couldn't figure it out, so would not isolate any part until they knew what part to isolate. They put in a ticket to TAS, which I assume is advance support at Toyota. The data they sent had too large a gap in frames, so they were instructed to run the scan again at a faster rate then send in the data, so that they could see individual sensors going off and on to better clue in. Of course this means another 2 hours or so diagnostic time, at over $100/hour. I said not a chance. $500 to diagnose? No. Their Master Mechanic told me everything I already knew, and nothing I didn't. Wonderful.

Ran like Holy ****, would barely stay running, tank near empty so pulled into a station. Filled it up, it dies trying to leave the pump. And then...

Seems like it is miraculously better. New gas in the lines and cylinders, and lo and behold I am not seeing a bunch of negative IGN timing on the scanner, no noticeable hesitation, and the RPMs are holding steady. Now, the engine is at operating temp so it has acted better in that state, but I was still seeing negative IGN when accelerating, hesitating on acceleration, and getting the occasional misfire prior. The several miles from the station to home - nothing.

Fingers crossed, but if it turns over fine in the morning when the engine temp is 40F or lower, then it is solved. If so, will be the most expensive tank of gas I ever purchased. We shall see.

 

I hope it is fixed! Maybe a tank of bad gas?

 

I am calling it officially: bad gas. Engine water temp was 40F this morning, and it cranked over easily and stayed at proper RPMs with no hiccup or issue. It had not done that the entire last tank. Last night I did some test driving and had no hesitations, virtually no negative IGN values, and no drops in RPM when accelerating.

Now the manual states I have an 18.5 gallon tank, and the fill-up clicked of at 13 gallons last night, so that would mean I had about 5 gallons still in the tank, give or take (I've never been able to put more than 14 gallons in it). Which means I still may have some crap in there, so by the next tank it should be even better. Appears that the low fuel warning indicator comes on then when there is still 5 gals in the tank. Huh.

 

For your next refill, I would add some Heet or other fuel treatment to help. $5 bottle of dry gas is worth it in my opinion.
Thanks for the update.

 

I added the Heat to that crap tank immediately, as I was on the mind set that the gas was maybe flaky. I had also put in a bottle of Techron since I did an oil change (my standard is to do Techron every OCI). My plan now is to fill with premium when I hit half a tank (tonight or tomorrow morning). I am curious what made the gas "bad", since I did add the Heat to it. My DIY instincts are to roll up my sleeves and pull the fuel pump assembly out, as well as each injector, and give them all some TLC. But, my garage is full of crap, so I work outdoors, and it is getting nice and cold these days. Makes that kind of work less fun And, it is purring like a kitten right now, so ??

 

Just as an update - I have had no repeat of the issue since. I am already mostly through an OCI, and over these last few thousand miles no repeats of the issue.

 

Great job, thanks for posting back with the fix.