Computer Problem?

[akewlguy]

Hopeful someone can send me in the right direction.

My mechanic thinks my computer is bad... Wanted a second opinion before we replace.

Four weeks ago my 93LS 400 was parked. When I started the car the check engine light was on and power was minimal. I started to give gas and there was minimal power. After a mile I stopped car to look at engine and listen. Turned off car and waited a few minutes. Started car and started to drive to mechanic. The car was sorta moving, but the check engine light would come on every second and almost stall. I dropped to Low and took it easy for a few miles to the shop. Mechanic started car next day and no problem. He hooked up code machine and no problems.

Two weeks goes by I put 250 miles on the LEXUS and nothing happens. Then all of a sudden check engine light and instant power loss. I pull over and then went through the same process of getting it to the mechanic. Mechanic this time is unable to get a code, since machine will not connect. Three days later he brings inside shop. Starts up and everything is okay. Troubleshooting machine hooks up and no error code. He suspects computer and knows the engines is all messed up, mis firing and dumping fuel when the problem occurs. I did spell fuel one time.

So we can not connect when it is messed up, but no error when it runs right. He did check wires and does not see a problem. Calling all LEXUS gods please help. I am driving my wifes GS300 and I miss my LS.

[93ls400walt]

If the check engine light is coming on then there should be a stored code. Also ask him to jump the OBD connector to run in Test mode. Manuel states that Test mode has " HIGH SENSING ABILITY TO DETECT MALFUNCTIONS "

STEPS

1 battery 11V or more

2 Throttle valve fully closed

3 trans in neutral

4 A/C off

5 turn ing switch off

6 use Wire to jump TE2 AND E1

a; turn ing. switch on and check if CEL light is flashing, if not test mode will not work

7 START ENGINE

8 simulate conditions of prior malfunction

9 after road test connect with wire TE1 and E1

10 READ THE CODES FROM THE MALFUNCTION INDICATOR

11 remove the wires from TE1,TE2 AND E2

hints

Test mode does not work if TE1 and E2 are connected after the ign. switch is turned on

when engine is not cranked code 43 is output, but this is not abnormal

when the shift lever is in D, 2, L or R or when the A/C is on or when the accelerator pedal is depressed, code 51 is output, but this is not abnormal