Driving around town no problem but getting on the freeway or anytime I give it lots of gas it surges, feels like it is going to die, like I am running out of gas, plus the Service Engine Light comes on. If I let up on the accelerator, 30 seconds later the Service Engine Light goes off and the car runs fine. I don't know how long it has been going on since most of my driving is in the city at low speeds. Power steering pump replaced last week.
Any ideas?
Thanks, Mary

 

Hey Mary,
I just had the exact same problem and after several weeks and several mechanics, I finally found out that my ECU was going bad and needed to have an ignition coil replaced as well.
Mine started w/ the jerking and blinking cel light but gradually got worse, to the point where i couldnt accel past 20 mph and terrible shaking..eventually the car wouldnt start at all...
I had the ECU and ignition coil replaced, just got my car back last thursday, its running fine now.

have a diagnostics performed on your car (autozone does it for free) if its code 41 (TPS Sensor) its more than likely that your ECU is going bad, i have a 94 also. I had my TPS Replaced, that did nothing, sparks n wires, fuel filter,etc..

if possible, find a mechanic that specializes in Toyota's and Lexus, i wouldnt recommend taking it to a lexus dealer, they'll just rip you off.

i hope this helps you and anyone else that has the dreaded "bucking/jerking/blinking cel" syndrome...i searched the internet for weeks and never found a clear cut answer..

KPZ

 

The only thing I would suggest out of this is "Autozone will check codes for free" I don't see how a code 41 (TPS sensor) indicates that the ECU will be bad. Might have been on yours but telling someone to change the ECU instead of the TPS if it's a code 41 is outragous. Especially with a $800 or $900 difference in price. Always try the cheaper stuff first. Also, Lexus dealers don't "rip you off" they just charge more because these cars are so complex.
I'd say have the codes checked and then let us know what comes up.

 

@ Deanshark

Never said get an ECU before TPS..i actually stated "its more than likely its the ecu going bad"
regardless, i'm speaking on my experience, since i wasted alot of money "throwing parts" at it..

@ Mary
point is, get the codes, see whats wrong and find a qualified "honest" lexus/toyota mechanic, not everyone is lucky enough to find the latter..good luck,

 

Not trying to start any arguement but if you say "it's more then likely the ECU is going bad" to an unexperienced person (not saying that she is but maybe) they are going to think "hey, I'll change the ECU"
Either way, as both of us said, gotta get the codes checked and go from there. Your problem sounds like it was your coil, I had the same "jerking and bucking" and mine turned out to be the AFM. So, it could be all kinds of different things causing the same feeling.
Codes first.

 

Thank you for the help. I have been out of town but will take it in tomorrow if I can to check the code. Will get back to you when I know. Mary

 

Hi Guys, it is a code 41. The mechanic showed me where the TPS is and it didn't look difficult to take off and put a new one. Does it have to be calibrated? I am inexperienced but am pretty mechanical, for a woman anyway.
Thanks, Mary

 

Hey Mary, nice to see a woman that will twist a wrench. If you do change it make sure you change the right one b/c there is also a "sub" TPS along side of the TPS. I know they're adjustable but I'm not sure how or if it needs to be adjusted before it goes on. If you change it and it doesn't work I think you can return it. (if bought at a local store) If it doesn't help then, as KPZ said, the ECU can be bad. (Or a bad wire between the two) I know there are tests you can do on them with a volt/ohm meter but I can't get to my manual right now, it's in my car under 20 inches of snow from last night. It must be nice to be in Hi.

 

Mary, this tutorial http://www.lexls.com/tutorials/EFI/tps.html will show you how to change, and adjust, the TPS. The "sub" TPS I mentioned is used in conjunction with traction control, which the car in this tutorial doesn't have. Hope this helps you out, I'm sure it will.
lexls is awesome.

 

Hi Deanshark.
Thank you so much for your help. I skimmed the tutorial and think I can do this. I am headed to California for a while so will tackle it when I get back. Hawaii's weather is the greatest! Hope you have a mild CT winter.
Mary

 

Hi - finally can respond to the thread about the TPS and the ECM. My son changed the TPS but it did not fix the problem so replaced the ECM which fixed the problem in terms of power, there is still a jump or stutter. I wonder if it isn't a spark plug problem. Thanks for all your help. Mary