I have had this almost exact same problem on my 92 sc300 5 speed. Iv checked every sensor, replaced parts, full tune up, still no changes... My master tech at the shop looked at it for half an hour about a week ago and said "yea you got a shark here". meaning its a problem vehicle that he needs time on. If he can figure out anything on my car while were slow during the holiday seasons ill let you know.

 

I finally figured it out. I traced it to the crankshaft position sensor connector. Although it was connected to the sensor, an extra push with extra pressure got it "clicked in". A test run revealed a strong pull all the way to redline! No missing or bucking - just smooth acceleration.

Thanks everyone for the ideas .... I now have the dubious honor of owning the most expensive sensor connector in the world.

 

"Check/replace the simple/cheap stuff first and LOOK everything over real good..ie..vacume lines, electrical connections, grounds etc. Good luck and keep us posted on the fix. It is usually quite simple and "obvious" once you troubleshoot and find it. They are Toyota's remember...."

94SC4, glad you finally found your problem. In my post to you on on Dec 3rd (a week after you posted your problem), I stated the above, surprised it took you so long to find and cost so much to rectify. When I usually state to LOOK, I usually state to TRIPLE CHECK as well, my bad......A good/high powered flash light and a patient/inquisitive mind are the best tools in your "tool box".

 

sounds to me its an electronic issue, and not mechanical like some of you are suggesting.

check the maf, crank shaft sensor, and tps firstly. swap out parts if you can and run it to eliminate possibility.



edit* oops, got it fix, awesome pants! tanks for letting us know.

 

wait you said they did a car wash?....did he happen to wash your engine bay also? don't know about the v8 but on the v6, that will screw you with the idling problem.

 

Glad you found the problem. Sucks you spent all that dinero. BUT your SC is now in tip top shape. Just replace your fuel filter.