Acceleration Lag, Driving me Crazy!

[LV2DRFT]

I'm driving a 2003 Camry Solara with the 2.4L 4 cylinder engine, 80,000 miles on it. Here's what I'm experiencing:

When I step on the gas, after stopping the car (i.e. a stop sign) I will occasionally (5-15% of the time) notice "hesitation." This happens after I press down on the gas pedal, before the car starts moving. It feels like it's chugging up or missing in some way... like it's "lagging" to go. Once I'm moving, it's not a problem, it seems to happen almost exclusively in this type of "idle-to-moving" situation. On rare occasions (twice) I've even experienced an engine cut-out. The engine turned itself off after I attempted to merge out into traffic from a stop (not a very happy situation to be in) It is more likely to happen after first starting the car. I'm noticing a little more smoke than what I would expect come out of the exhaust after starting the car first thing in the morning too. It doesn't stay this way, just the first puff of smoke that comes out after turning the car on... it's a little more than what I would call typical.

I attempted a few routine maintenance tasks to try and remedy the situation:
1) Oil change-- didn't help at all
2) Installed new spark plugs-- didn't help at all
** Also I checked under the hood with the engine running at nighttime.. I didn't see any electrical arching coming from the wires. **
3) Replaced fuel filter-- seemed to help a little bit. The car used to have the above mentioned problems as well as it would shake when idling. Since then I haven't notice any shaking while idling (and the engine hasn't cut out completely since then, knock on wood). I'm still feeling the lag though, but maybe about only 75% as intense now.

Also, I'll note it really doesn't feel like it's a transmission problem at all. Shifts perfectly fine and smooth, goes from park to drive to reverse just fine. I don't hear any grinding or anything from the gears. I'm still learning about cars and don't have much experience. I think that what I've discovered trying to fix it might hopefully be enough information for one of you more experienced members to help guide me in the right direction. My wife thinks it could be because of the battery. We tested the battery and got the code for "needs to be replaced," but I didn't think a weak battery could cause this problem, could it? The headlights and radio all work perfectly fine, and it starts right up without excessive cranking. I've got more research to do, and I was thinking about looking into the exhaust components (catalytic convertor, o2 sensor, etc.), or maybe the fuel pump, or God knows what else.

Can anybody help? Has anybody experienced this before? How did you fix it?

Thank you SO much in advance!

[JerryR]

Originally Posted by :

When I step on the gas, after stopping the car (i.e. a stop sign) I will [I

occasionally[/I] (5-15% of the time) notice "hesitation." This happens after I press down on the gas pedal, before the car starts moving. It feels like it's chugging up or missing in some way... like it's "lagging" to go. Can anybody help? Has anybody experienced this before? How did you fix it?

Thank you SO much in advance!

This is a long shot(I'm no expert either), but..
If what you are calling "hesitation" or "lagging" a condition where you try to accelerate from a dead stop, and nothing happens (car does not move/RPM does not change) until you press the accelerator harder, then I suspect you have crud buildup in the throttle body.
If that's the case, cleanup with a throttle body cleaning solvent(make sure it's Oxygen sensor safe) usually clears the problem.
HTH
JerryR

[TheJourneyman]

Pull your PCV and see if it is dirty or not moving freely inside, a quick look and a quick breath through it usually gives you a good idea.

Honestly, if it hasn't been changed and/or you don't know if it has ever been changed just do it. They are cheap.

[TheJourneyman]

Just to flesh out my answer a bit, a failing PCV can cause all of the symptoms you are explaining to a some degree depending on how it is failing.

In your case, if it is actually the PCV, it sounds like it is not closing properly sometimes, or at all. This can be because of it simply being worn out or built up with sludge inside at the mechanism. If it doesn't close, it is messing with your air/fuel mixture slightly which you would notice most prominently at points where you go from idle to acceleration; which changes your vacuum pressure that *normally*operates the PCV in a open close fashion.

At idle it can cause a roughness because of the engine fighting an improper mixture.

Whether this is the problem or not, I would change it either way, they are cheap as dirt and are almost always a simple pullout/pushin in replacement.

Good luck!

[LV2DRFT]

Thanks Jerry and Journeyman!

I'll start with replacing the PCV valve (well, learning what that is, how to replace it, then replace it)

If that's a no, I'll try the cleaner.

I need to replace the battery anyway...

And I'll post my findings.

Thanks in advance!

[LV2DRFT]

I've been doing more research (haven't had much of a chance to look at the car as my wife is always driving it) and I have discovered a pretty consistent answer when others asked a similar question, that it could be bad valve stem seals or guides. I don't even know what exactly this is, but apparently if they are going bad, they will shrink when cold, let some oil leak into the combustion chamber, then the oil will burn off at startup, and when the engine gets hot they will expand, not allowing oil in and therefore not letting the car smoke. The 10-20 second plume of smoke at startup would be the oil burning. I wonder if it could be this as well... and the car hesitating and then sometimes stalling would be a result of the oil still in the combustion chamber messing things up until it all burns out. Or this could be an ADDITIONAL problem to add to the list... So I'm going to find out how to check for this too...

[LV2DRFT]

OK... Spent a little time looking at things tonight:

Check engine light lights up when starting the car like it should.. so the bulb is not burnt out. I'm still not getting a check engine light so no code will be accessible.

Coolant level is fine. Coolant is fine.

Oil level is fine... no noticible loss of oil. Oil is brown, smells like oil, not like antifreeze.

I've spent the last 2 hours trying to find the damn PCV valve. IT should be so easy... where is it? Can anybody show me a picture or something of where this damn thing is?

Thanks!

[ajkalian]

You might be looking in the wrong places. Check out this thread.

The Free Mod Series - Part I Quicker Transmission Shifting

It sounds like snake oil, but adjusting the throttle cable and the transmission kick down cable makes a world of difference.

I'm not sure it this would apply to your setup, but it's worth a look see. Doesn't cost anything either.


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