Mike234588

My problem started a week ago my car studdenly stalled on me and won't start o/d light and check engine light were on. I get it towed to a shop they go to start it the next day it starts right up. They can't figure out what was wrong I go to drive to get it scanned for codes no codes. On the way it stalls and then if you hold your foot on the gas it will start. I made it home go back outside to start it and it's back to just cracking and the o/d light was on. I'm lost at this point help is needed. It's a 94 ls400 thanks

dicer

Start with the ripple test.

Mike234588

What is the ripple test ? Thank you

dicer

https://www.clublexus.com/forums/ls-...-by-yamae.html

Mike234588

Thanks my challenge will be getting the car to start. But I will use this and get back with you thank you

Mike234588

Any possibility it could be the crank postion sensor or the tps? Do you have anything on how to check the crank sensor or tps ? Thanks

dicer

Yeah could be anything, but usually a code is set with sensor problems. The best check is when it acts up to use a scope and see if it sends a signal.
With an intermittent I don't think you will find a problem with a simple test, as it either needs heat or vibration or both.

Mike234588

Okay your right so I'm guessing that these computer store codes? I just wonder how if mine does. why mine didn't it and what does the o/d and check engine light mean together as one. It runs fine after it starts this is just bizarre. I'm going to do the test you sent me to check the computer. Have you ever heard of this before ? Thanks I'll keep you posted

Yamae

A dead ECU can't generate codes. I'd simply check the ECU observing the ripple level.
Those QAS capacitors can't live long and the ripple level becomes too high causing the ECU malfunction.

Mike234588

Alright I'll check it and let you know thank you

Mike234588

Will I need the same exact part number for my ecu ? Thanks I would think so but just asking to make sure thanks

dicer

What ever the numbers are on the old unit is what you need.

This is from the LScowboy ecu thread. And maybe something Yamae posted I don't know.
----------------------------------------------------------------------------------------------------------------

As far as I investigate the variation of the ECU for the North American market, there are ECUs as follow.

ECU Part Number USA/CND Some for Taiwan
-----------------------------------------------
90-93 model
Part Number, Production Date, Model(Description)
89661-50010, 05/1989-08/1990
89661-50020, 05/1989-08/1990 W(TRACTION CONTROL)
89661-50030, 05/1989-08/1990 CALIFORNIA SPEC
89661-50031, 08/1990-09/1990
89661-50032, 09/1990-08/1992
89661-50040, 05/1989-08/1990 CALIFORNIA SPEC & W(TRACTION CONTROL)
89661-50041, 08/1990-09/1990 W(TRACTION CONTROL)
89661-50042, 09/1990-08/1992 W(TRACTION CONTROL)
89661-50140, 08/1992-01/1993
89661-50141, 01/1993-08/1993
89661-50142, 08/1993-10/1994
89661-50150, 08/1992-01/1993 CALIFORNIA SPEC
89661-50151, 01/1993-01/1994 CALIFORNIA SPEC
------------------------------------------------
94-97 Model
89661-50220, 10/1994-02/1995
89661-50221, 02/1995-08/1995
89661-50230, 10/1994-02/1995 CALIFORNIA SPEC
89661-50231, 02/1995-08/1995 CALIFORNIA SPEC
89661-50290, 10/1994-02/1995 USA TAIWAN SPEC
89661-50291, 02/1995-08/1995 USA TAIWAN SPEC
89661-50302, 08/1995-09/1995
89661-50303, 09/1995-08/1996
89661-50330, 08/1995-08/1996 USA TAIWAN SPEC
89661-50340, 08/1996-09/1996
89661-50341, 09/1996-07/1997
89661-50370, 08/1996-11/1996 USA TAIWAN SPEC
89661-50371, 11/1996-07/1997 USA TAIWAN SPEC
------------------------------------------------
Model after 98
89661-50430, 07/1997-10/1997
89661-50431, 10/1997-11/1997
89661-50433, 11/1997-02/1998
89661-50434, 02/1998-08/1998
89661-50480, 07/1997-10/1997 USA TAIWAN SPEC
89661-50481, 10/1997-11/1997 USA TAIWAN SPEC
89661-50483, 11/1997-02/1998 USA TAIWAN SPEC
89661-50484, 02/1998-08/1998 USA TAIWAN SPEC
89661-50501, 08/1998-05/1999
89661-50502, 05/1999-08/1999
89661-50511, 08/1998-05/1999 USA TAIWAN SPEC
89661-50512, 05/1999-08/1999 USA TAIWAN SPEC
89661-50530, 08/1999-11/1999
89661-50531, 11/1999-08/2000
89661-50540, 08/1999-08/2000 USA TAIWAN SPEC

Mike234588

So the capacitors Were my issue. But I have a question does the ecu need to be reprogrammed? Like for Example now my radio isn't working thanks

dicer

The ecu on the gen 1's does not need any reprogramming. The radio is lilkely out because there was a security code set in it. The dealer or a qualified lock smith with the right info can unlock it. That info is top secret only for certain people.

If there was no security code set, then, did you not disconnect the battery before trying to remove the ecu? If so that could be the cause of any other strange electronics problems. Always disconnect the battery before touching any of the electrical, except lights and O2 sensors, but in those cases the key is off and in your pocket.

Mike234588

Yeah I had the battery disconnected. Yesterday I got the ecu and installed it then I Hooked up the battery. I didn't actually use the radio is was on but had the volume all the way down. Then today I drove it this morning and no noise. Then this afternoon I'm hearing this wooting noise when the radio is on no matter if the cd is in on or the normal fm. I meant to say something about the noise earlier could the amplifier be bad ? Thanks or do I just need the code to reset it thank you