Toyota Repair: 95 Corolla BUCKING UNDER ACCELERATION, precision toyota, lead tech

Question
Hi Paul:

Thanks for the help.
I have a 95 corolla (1.8litre) w/ automatic transmission and 100,000 miles on it.  I periodicaly have the injectors cleaned and the transmission fluid totally changed out.

My wife drives the car and said it was jerking when she would start driving home from work.
(She leaves work and goes about a 1/4 mile on an incline to get on the interstate)  We also live in Tampa.


3 months ago it was running rough so I took it in to a local garage for a tuneup.  They installed aftermarket wires,cap,rotor and sparkplugs.  The car ran fine for about a month.  Then car then started jerking more frequently (When accelerating)at times it was so bad you had to drive it as if you had an egg under your foot.

I took it back to the mechanic who changed the fuel filter and installed a fuel pump (in tank)
The fuel pump didn't fix the problem so he removed it and said to go to the dealer.

PS: car displays no codes and the problem occurs even when the car is in neutral and revved up.

I took it to Precision Toyota and their lead tech. "Jose" thought it was the distributor.  He ordered then installed the distributor w/ cap,coil and rotor.  It did not fix the problem so he put the original distributor back in.
He put a test light on the injector lead and when he revved the motor in neutral the car would start breaking up and the test light would flash erratically.

He then checked the throttle position switch, disconnected the exhaust, ran a can of injector cleaner thru it and couldn't find out what was wrong.  at this time I had to get the car to use for work so I picked it up.(it was driveable under very light acceleration)
 At the time "Jose" said he "thought" the problem "might" be with the "brain".

I put Premium gas with a can of Techron and started driving the car and it seemed to get better.  after many tanks of gas the bucking was reduced and the problem only occurred under HARD acceleration.  It seemed to be fixed,  The problem is now back when accelerating under modest acceleration.

I changed out the map sensor and the problem persisted.  

At this point I don't know what to do, I have owned the car for 3 years and maintained it well and plan on keeping it for another 3-5 years.

One last thing it seems that the problem might be temperature related.  The problem seemed to start again when it started getting 80-85 degree F.

Answer
from what has been said i have to agree with jose. it seems to be an intermittant computer problem. i'm a toyota tech as u know and from what is said it sounds right. i've seen vehicles have similar problems and had to replace the pcm. but one thing i would do is check the data list for any abnormal data first before i put a pcm in it. go back to jose and ask him to monitor pid data, he'll know what is means. and please get back me.