Anyone please help, you won't believe this..

[jayjay]

Ok, this is going to sound really weird. (1992 SC400) 4.0 L
I had a big problem of not running good and no power. I put in a new fuel pump,coded check engine light to maf (swapped one from a junk yard). Did some diagnostics and it said that the ECU needed to be replaced. I sent the ECU out for repair and it came back. PROBLEM STILL NOT FIXED.

I send it to Lexus and they say the coil is bad and they replace it. My son drives the car home. When we get home , I drive it down the street.
I notice it is going from 1st gear right to 3rd gear. When you floor the gas it does not down shift to 2nd gear. If you put the gear shifter physically into 2nd gear, it down shifs to second and everything seems to work but you have to do it manually.

A half an hour later.
The car will start and idle but when you give it gas, it boggs and wants to stall. If you leave your foot on the gas it will bog bog bog and rev to about 1500 rpm.s and repeat . I can't even take it out of the driveway.

What happened in that 6 or 7 mile drive home from the Lexus dealership ???

 

[4U2QUIK]

it sounds like it's still a maf problem.

 

[BlackUZZ31]

or a throttle position sensor

 

[sideshow]

maybe lexus put a spell on it heheheeh

 

[Lextreme II]

Perhaps a new problem. I am sure the car was driveable when Lexus release it to you. So whatever the problem it came in was fixed and a new problem arise.

 

[4U2QUIK]

I'm guessing it's an intermittant problem with the maf and or tps wires.

 

[Cobber]

What happened in that 6 or 7 mile drive home from the Lexus dealership ???

I would say your son flogged the guts out of it...........!

Pull the codes it could be anything.

 

[jayjay]

OK, I found it !!!!!
Hope this helps alot of people.
Since I had sent the ECU out to be fixed. I didnt put the carpet back down or cover the ECU. So after the Lexus dealership swapped the coil with a new one and fixed it , we drove it home and all Holy crap happened.
Knowing that the last thing I did was put the interior back together, it dawned on me. It has to be in the wiring.
I had my son get in it and watch the check engine light (since it was on and coding MAF) I also told him to pump the gas (because when u touched the gas it would bog out).
I moved all the wires and it would now rev up, the check engine light also went out.
So i played with it until i found "The Wire". It is the wire that feeds the MAF. Every time I move it one way it would bog and the check engine light would come on, when I move it into the connector (that plugs into the ecu) it would run perfect.

We drove it, it runs perfect, it shifts perfect.
I am going to take the female piece out of the connector and crimp it a little bit to make sure it gets a better connection.

My backround it in telephone wires and I knew that it had to be a high resistant open (loose connection) because it all started after I put the cover back on the ECU and put the carpet back down.

Folks, I would check those connections " FIRST ". I just spent alot of money on this car starting with the MAF then the ECU, fuel pump etc (coil definately was the poor spark).
I believe this would have been kicked around from mechanic to mechanic and shop to shop if I had not done it my self.

I also think that it may solve the intermittent start stall problem as well.
We will wait and see.
So now the car runs fine and no more check engine light with a MAF and IAT sensor codes (24 and 31)

Hope this helps some of you and thanks for the advice.

LOL , One for the telephone guy.....

 

[sideshow]

loose connections happen because too many fkheads
play with the car trying to fix it
best to find good mechanic and stick with them
I've fixed 5 sc400s that stall as u move
bad connection on Efi relay
like I always say these imports start playing up after 15 or so years
heeheh