98 Toyota Camry Sputter Stall

I have a 98 Toyota Camry with 120K miles. Great shape. But, fairly frequently, it decides to get into a stalling mode where I have to keep the accelerator depressed or it will stall (makes a fun drive to work as I have to put it in park every time I stop at a light so I can rev the engine). I think it seems to be initiated when I either ‘floor’ the accelerator or am just being aggressive with the accelerator. Oil smell, too. When I leave the car overnight, it usually is fine the next morning, like nothing ever happened. Been to the dealer, no help (they said they need the car in their shop when it is happening but have not been able to get the car there quick enough for them to look at it before it recovers). Seems like a form of flooding but it happens way to often. I have also poured tons of fuel injector cleaner and water remover but it still happens.

Has anyone experienced this? Any advice?

When was the last tuneup?

When you floor the accelerator, the ECU richens the mix. A richer mix requires a healthy spark. If your ignition system is weak, not putting out a strong spark, misfiring will happen and symptoms similar to flooding occur. It isn’t really flooding, it’s just inability to effectively burn the richer mix.

The problem could be complicated by the source of that oil smell. If your engine is wearing out you’ll be blowing combustion gasses past the rings (known as blowby) and pressurizing the crankcase. That can overwhelm the PCV valve, force oil out the main seals, past the valvecover gaskets, and every other possible path. You’ll smell it.

Has this vehicle been neglected?

Forget the injector cleaner and drygas. Give the car a good, thorough tuneup, “read” the plugs looking for signs of poor combustion (wet electrodes, black buildup, encrusted electrodes, stuff like that) or overdue maintenance (electrodes that have long since vaporized). Check the PCV valve and check for signs of oil being forced out of every seal…signs of crankcase pressurization…signs of blowby.

If this doesn’t help or reveal any clues, post back. But start with these basics.

Also clean throttlebody with carb cleaner

That is excellent commentary. I will start there. Thank you very much.

Thank you. Let us know how you make out.

Hi again,
I made my appt for a tune-up at Toyota for next week. I talked candidly with the shop about what my issues were and asked what they would be looking for in “their” tuneup. Turns out that they really will do nothing that would address the issues in either their Basic or Full Tune-ups (although they do look at the PCV valve) and, again, recommended that, instead of a tune-up, I bring the car in while the problem is occuring or they can also try to make it occur. But, I have been down this EXACT road before with them. So, now I am in a quandry. Your diagnosis seems right on. The vehicle has not been neglected so I am considering trying to direct the process into the most likely areas. I could see if they can simply attack the plugs and the ignition system (by the way I had Sears put in a new battery last week so that is of no issue)…and/or I could direct them in the “blowby” area (I think this is a strong contender because it is an old engine and it does happen in instances where I am accelerating and the presssures are higher…is this ring job a costly $$$ undertaking?..don’t want to get into repair work that is more expensive than the car is worth). I hate to direct them to areas that I feel that they should know about but I don’t want to waste a whole day again with them finding “nothing wrong, sorry” and then send me on my merry way (until I stall). I would appreciate you thoughts/opinions.

P.S. Do you own a shop that I could take it to? (I think you know your stuff)

Took the car into Toyota. They could not replicate the problem but I had them do a tune-up which included all the things you all mentioned. So I have new plugs and PCV and a clean throttle body (and a bunch of other things included in the tune-up). So far so good. I am crossing my fingers. Thanks for your help.

Never use CARB cleaner to clean a throttle body. Use a throttle body/air intake cleaner. Why? Some throttle bodies have a special coating inside that prevent deposits from building up. Using a carb cleaner can either etch or remove this special coating causing deposits to accumulate faster. After that, you can use all the carb cleaner you want.

Tester

Well, it still happens, initiated by the same circumstance. I think maybe that the car engine is old enough and has a mileage that such a problem can be expected. Any final advice for me?