99 4 cyl. camry power loss.
 

My car has developed an occasional power loss. Once in a while, it is like it wont respond to the accelerator, until i floor it, then usually the problem goes away. I talked to a guy and he said it sounded like possibly bad gas, or that when the fuel level gets low its is sucking up crap that has built up in the gas tank. I filled the tank with gas from a better quality gas station, and it seemed to go away, but did happen once when the tank was full. Seems to happen every couple of weeks. No check engine light, no codes. Any ideas?

The fuel system is not monitored with the check engine system other then to monitor mixture.

Any relationship to fuel filling frequency? The fuel system has a storage container for fuel vapors. On occasion the container is switched into the engine intake manifold to be burned.

Any relationship to fuel tank level and this problem?

How about engine hot or cold?

Can try to add a container of fuel system cleaner.

The pump is picking up the fuel in the same area regardless of fuel level. Debris should not be an issue.

It seems to be a bit better when there is more gas in the tank. It is at about 1/4 now.
This morning it was about 20 degrees and it ran fine. Lunch time, ~30 degrees, drove home 4 miles it ran fine, on the ride back to work it did it again.
It doesn't happen every day, in fact it's more like every few weeks or so.
The first time this happened I ran seafoam in the fuel tank. This was about 2 months ago.
I would say it happens more when engine is warmed up.
I almost feel like I don't have enough symptoms to diagnose this.

The weird thing about it, is that it doesn't seem to happen the first time I drive it for the day. It seems like first time it's ok, then when i let it sit for a bit, like for lunch break, it does it.

Might be a failing fuel pump or fuel pressure regulator which is mounted on the pump.

Any relationship to weather as in rain?

Perhaps ETC for computer (water temp sensor for computer), TPS, MAP sensor. Can test these if having some service data and an ohm meter.

Weather does not change it, neither does rain.
The tank is full now, and it has been running fine. :confused:

See what happens.

I have not had a problem in weeks. I have been keeping the tank over 1/2 full.
Now on to the ABS problem.

You can also add some dry gas in there which is suppose to absorb any water and help it burn off.
If the problem persists when the level is below 1/2 then I would suspect something wrong with the pump in the tank. Fuel pumps actually get lubrication from the fuel and if it has been run down low a few times it can take a toll.

It figures, I open my mouth about it not happening, and it happens again!
I drove home on lunch break, about 10 minutes, let it sit about 10 minutes, and it happened again! Stopped at a stop sign, engine stumbled. Then seemed like pressing the gas did nothing. Then RPM went to about 4k, car seemed to not want to move. Floored it then it started working ok. Fuel tank is about 7/8 full. It's about 50 degrees today. It ran fine 2 weeks ago when it was ~60.
:mad::confused:

It's back!
 

This problem went away for months, now it's back. For the past week or so it's been doing it every day. It seems to run fine the first time I drive it, then if I shut it off, let it sit for a few minutes it will do it. It will run fine as long as I drive it, until I shut it off and let it sit for a while. It has to have something to do with heating up then cooling down. :mad: Frustrating.

It is possible for the trans to start to slip. Try to differentiate between the engine acting up but the car still moves, and engine issues but the car does not move.

Have you cleaned the IAC valve?

How about fuel pump and the fuel pressure regulator?

I have popped it in neutral when it happened, and it still just bogs.
If i start it after it's completely cooled down and can drive it as long as i won't with no problem, but if i shut it off for 10-15 minutes, that is when i have problems.

When it bogs, does it eventually start to run normally? As in a momentary lack of fuel?

When you have the problem. Might try using a freeze spray on sensors such as cam/crank, ETC. This to cool them down.

It will run normally after it warms back up.
That is a good idea, I should try that.

A part may be heat soaking and getting too hot.