Hi

I have fitted a 1uzfe lexus engine (4.0l) with standard ECU and standard A340 Auto transmission in a Mercedes Benz 380 SEC

(I 've also fitted carbon fibre replica mustang front end and taillights, but that's another issue)

The engine /transmission /ECU combo comes out of a mid nineties Lexus LS400 so I'm hoping some knowledgeable Lexus tech can help me out.

The problem I have is that the transmission will not select 1st gear when I come to stop and take off again (for example when stopped at a robot)
When the car is first started, it will take off in 1st, but it seems when the engine/transmission warms up it does not want to select 1st gear, even if I move the lever to the "low" position.

The transmission shifts through gears fine once moving and even downshifts when required. I have adjusted the throttle cable to spec and even advanced it a bit, but it makes no difference.

Does anybody have an idea what the problem could be ?
Is there a way to force the gearbox into first gear (apart from a new controller)?
I thought it could be some sort of traction control intervention between the engine and gearbox , and if so ,is there a way to disconnect it (the TPS for the traction control is still fitted on the engine).

I'm using a 3.46 diff (out of a Benz W116 350SE, the original 380 SEC a 2.46 diff ratio !!!) with 295/30/20 tyres on the rear, so a 2nd or it feels like maybe even 3rd gear start means the car is a total dog off the line, with lots of slip and noise with little movement.

Thanks

 

Here a pic of the controller I built to solve the transmission problem!!





Rotary Switch controls shifts manually