2000 Solara V6 SE 5pd Acceleration issues

[phild1087]

Hey all, first post here. I searched the forums like a good little noob, and really didn't find anything that quite matched my situation...

I have a 2000 V6 Solara SE with a 5pd transmission with about 100k miles on it. Regular oil changes and and basic maintenance have always been done.

About 10 months ago, I got a check engine light for a misfire. We checked everything over, and couldn't find any problems with anything. Cleared the code and never saw the light again. Car was running just fine. But about 8 months ago, I noticed that when I really need to give the car some gas, like pulling out into traffic and such, I was getting surges in the acceleration, which worsened as I went into the peak RPM ranges, and a little lack of overall "pep" in the performance, as well as a dip in gas mileage. Not drastic, but a few mpg from what I usually get (and I check every tank).

I changed the spark plugs a few months ago at a local Toyota dealer, as they were due to be changed anyway, and while it seems like my mileage is back to normal, I'm still having problems with the surging/uneven acceleration and some lack of power. I have no idea what it could be, but I'm thinking maybe the misfire is still occurring, or maybe I have some fuel/air intake problems?

Any help would be appreciated, and if you need any more information, I'll be happy to try to answer as best I can.

Thanks so much!!!

[AliRazoR]

Originally Posted by phild1087

Hey all, first post here. I searched the forums like a good little noob, and really didn't find anything that quite matched my situation...

I have a 2000 V6 Solara SE with a 5pd transmission with about 100k miles on it. Regular oil changes and and basic maintenance have always been done.

About 10 months ago, I got a check engine light for a misfire. We checked everything over, and couldn't find any problems with anything. Cleared the code and never saw the light again. Car was running just fine. But about 8 months ago, I noticed that when I really need to give the car some gas, like pulling out into traffic and such, I was getting surges in the acceleration, which worsened as I went into the peak RPM ranges, and a little lack of overall "pep" in the performance, as well as a dip in gas mileage. Not drastic, but a few mpg from what I usually get (and I check every tank).

I changed the spark plugs a few months ago at a local Toyota dealer, as they were due to be changed anyway, and while it seems like my mileage is back to normal, I'm still having problems with the surging/uneven acceleration and some lack of power. I have no idea what it could be, but I'm thinking maybe the misfire is still occurring, or maybe I have some fuel/air intake problems?

Any help would be appreciated, and if you need any more information, I'll be happy to try to answer as best I can.

Thanks so much!!!

have you ever changed the fuel filter?
maybe your injectors problem?(check resistance of each injector)

[1gse]

Do you remember the code?

[Akfahad]

could possibly be the coil pack as well.

[arabianobsession]

Also see if any gaskets are blown and leaking. I had that problem once on an older car, it had a lack of power and surged because the engine would detect weird amounts of air seeping in where the gasket blew out and would try to compensate for it. I, too, had a dip in gas mileage and performance.

[phild1087]

I'm pretty sure the spark plugs didn't do much to help my mileage, as over the past few months I've still been getting consistently lower mileage. It was probably just temporary wishful thinking.

Miles used to be around 25 around town, and now it's down to 20-21. I don't know if that's considered "significant" or not.

One other thing that might worth noting: I did some other reading in this forum, and apparently the knock sensors on the 1MZ-FE do NOT handle gas below a 91 octane very well, and around the time I started noticing problems, I switched to using 87 octane from using premium to try to free up a few bucks in my budget. I'm going to try switching back to premium for a while, and see if I can notice any difference in performance and/or mileage.

Side note: I live in Upper Michigan, and it's getting very cold this time of the year, and it takes the engine that much longer to warm up because outside temps are in the teens. Is that going to affect the numbers/performance at all, and make my observations worthless? Any fuel additives/cold weather tips people know for helping out your engine?

Sorry for the novella, I greatly appreciate any input/random thoughts, and I will activate email alerts for responses so I actually get back sooner than 10 months later this time

[arabianobsession]

^Cold weather is ALWAYS going to affect your MPG. My 2011 Camry averages 27 MPG in the summer, but now I'm only getting about 22. And that's with it being an I4!! There's not much you can do to stop it....just wait for warmer weather to come back is all. It's been pretty frigid here in Wisconsin the last week or so and what a difference it makes in the MPG.

[phild1087]

Well that's aggravating. Oh well. At least someone else out there feels my pain

I just saw you posted about the gasket leaking thing (when it came to the uneven/surging acceleration). Are there any other symptoms for if that is what's occurring?

[arabianobsession]

Not every time a gasket leaks will it do what I was talking about. Usually it's when a corner blows out.....besides the uneven/surging acceleration, you may also feel a major loss of power. Meaning, you could have your foot to the floor and it won't go, it's acting like it's feebly dying. *laughs*

Pop open the hood and check for oil leaks around the engine, and if you see any coolant leaking around the head gasket.

[phild1087]

Ohhhh okay. Yeah, nothing drastic with the power loss like that. Just slightly weaker acceleration that what it used to give, which the occasional surges in power. As far as I've seen from poking under the hood, no fluids have been leaking. I'll give a closer look next time though.

Any chance it might be a sensor? I had a Ford Probe that acted funny when the oxygen sensor (or mass airflow, can't remember exactly) went bad. Not sure if that has any bearing on this situation, just a thought.

[arabianobsession]

Could be a sensor....a friend of mine had an 02 Cavalier that wouldn't start because the Knock Sensor was effed up.

Check the MAF too, currently my 2000 Maxima is having acceleration problems too, it surges and bucks even, and I know the MAF is going bad.