aaron2414

Well im very glad I found this forum and as a new user I hope I am not duplicating a post similar to this. I have done a few days of searching and can't find anyone (so far) that has had this issue.

My problem:
I bought my first SC300 with the 2jz engine and auto tranny last week. I immediately noticed that if I floor it, my car will downshift correctly but then take it's sweet *** time getting up to speed. Its like it has very very limited power but everything else works. There is no jerking when I accelerate, no backfires or misses, and no smoke. I have NO check engine light on but I know something is not right at all.

What I have done so far:
I have changed out my instrument cluster (the tach and gas gauge werent reading and the speedo was off by almost 10mph)
I have also changed the TPS, MAF, and am anxiously awaiting a new ignition coil pack.

Im hoping maybe it's a ignition coil pack issue or even an O2 sensor possibly, but I figured the O2 would have thrown a code.

Any help or ideas would be great!
Nice to meet people who respond too,
Aaron J

aaron2414

*bump*
Update: I have completed a transmission flush and even added about 1/2 a bottle of Lucas Trans Fix to see if maybe it helped ANYTHING (the car has about 192k miles) and the problem remains exactly the same.

Feels electrical considering if I am at a stand still and FLOOR IT, the car doesn't jerk or sputter or anything... it just feels like its dragging an extra 2,000lbs and takes forever to get up to speed. The best example I can think of is that its like watching a normal car in slow motion. (goes all the way to redline and the speed matches where the tach is, but it all happens sooooo sloowwwww)

BenStoked

iTrader: (3)

a couple of things I want to ask just to verify.
1) full tuneup has been done (cap and rotor, plugs and wires, air filter etc.). Kinda implied by the work done, but want to maks sure it's done
2) tps has been properly adjusted, so has timing the distributor

also, it's possible the ecu is bad. typically associated with bad fuel economy, how's yours?

Nova

iTrader: (21)

i know my car felt like crap when it wasnt timed properly. if u can set the engine to top dead center and use a 5mm hex head to take the top timing belt cover off and check that everything lines up. it is a simple and quick way to eminate that.

also what car did u have before this SC, or how long have you been in this car. i noticed that they r not as fast as they look especially when they weigh close to 4000 lbs

aaron2414

Sorry for the long response time:
I haven't done a COMPLETE tune up but rather have replaced my TPS, MAF, manifold O2 sensors, ignition coil, and have installed a cold air intake. This was all done AFTER I noticed my problem in an attempt to fix it. My buddy and I checked that the timing was correct and it is dead on.

@BenStoked my gas mileage is actually horrid :-/ (something like 10-12mpg) That's why I replaced the O2 sensors thinking maybe they were the problem...but nothing has changed. I am thinking I should just get it diagnosed by Lexus and go from there. I don't have proper tools or know-how to check electrical problems and figure having them check things out will cost less than me throwing money at parts hoping they will fix the problem :-(

Any new ideas? or is this slowly approaching an ECU problem for sure?
Thanks guys,
Aaron J

aaron2414

...actually, I will post a youtube video of me driving here in a little bit so I can better show what's happening. Everyone says, "sc300's are just slow" but this is just ridiculous. Something is wrong LOL!
*video post soon*

aaron2414

http://www.youtube.com/watch?v=4USWjElJzi4

Here ya go peeps... this is me with my problem (I sound weird on video...anyways)

Tabaka

iTrader: (8)

damn, that's slower than my 300 NA

Has your engine ever been tuned? It's not getting enough air/fuel is my guess.

aaron2414

See that's the prob... it for sure hasn't been tuned (by me or anyone i know of) but it seems like an air fuel ratio prob... and I have replaced all air/fuel ratio sensors :-( ecu still?

LunaVyohr

You could try just resetting your ECU.

Cleanshots

iTrader: (2)

omg.. um check ur distributer, the timing and double check that the wires are all correct.. check the timing, then pull off the top so you can see the cam gears and make sure the timing belt is not off by a tooth or something.. change plugs, seafoam the car!

aaron2414

Well I have taken my exhaust off and found that my cat had come loose from the inside and was just plugging up the exhaust HOWEVER I am still having the same problem after gutting it. I have a good convo going on my youtube video I posted here as well but am making no headway.

The newest idea thrown my way was that because the cat had come loose, I might have fouled out the O2 sensor that sits AFTER the cat. Would this affect air/fuel? I was under the impression that the 2 O2 sensors on my exhaust manifold did that and the O2 sensor AFTER the cat was just to "taddle" on me if my catalytic converter wasn't functioning... oh yea, I have NO check engine light on either

aaron2414

wow...lots of views and no ideas :-( depressing... I got some work done on my other car (P.O.S. truck up on craiglist for sale btw) at a local shop and the manager said he would "hook me up" with a $50 diag as long as I came in on a Wednesday or Thursday. Im thinking that is my best route now :-(

BenStoked

iTrader: (3)

you never did actually say you got a tuneup (plugs, wires, cap and rotor), nor did you say the tps was adjusted to spec....

aaron2414

Nope didnt get a tune-up, wires are brand new from the dealership I bought it from, cap and rotor were taken apart and visually looked either brand new or within the past year new. Alternator is brand new, and tps was installed at the exact same angle as the stock one was (it has a groove made on it that matched a red line painted on the throttle body). Im honestly thinking its an ECU/ECM problem :-/