Trans problem

[Sudsy]

G'day all, iv'e got a bit of a problem with the trans in the 37 (1uzfe). It seems like it skips a gear when you take off, starts in first but feels like it jumps to 3rd or od and won't kick back until it gets a bit more speed up. If you change manually it works fine.
Any ideas:dunno: :dunno:

 

[spf_lexus]

Check your trasmission's line pressure... if it's set too soft the kickdown will be "lazy" and shifts will lag... it can also cause some issues w/ other sensors if it's overly soft/stiff. Try driving with car w/ the cable completely off, and then where it is right now, and then with it tightened up a few full rotations. If it ends up curing it ot improving, it wont cost anything. Worth a try

 

[litldv8]

no second gear

hi all i have the same drama with my ls400 1992. doesnt do it all the time but more prevailant when hot. manual shifting the box it works perfectly. did adjusting the kickdown fix this? any other ideas?

 

[sideshow]

has it always run like that
or just started
these autos run crap if no or incorrect speed signal
put a powerglide in it heheheeh

 

[litldv8]

i have had the car for about 6 months and it has always done it to me
why would i put a piece of holden **** like a powerglide in it

 

[sideshow]

litldv8 i presusre yr car is a factory car

so u must have a fault with a sensor or might even be the auto
u need to take it to a specialist maybe

but in a conversion sometimes the speed snesors are not correclty fitted or wired up
which makes gbox change gears at wrong intervals

but these still can be many other causes of this problem

if i took car for drive doesnt take long to test if its mechanical or electrical

 

[Sudsy]

First of all thanks to spf lexus for the reply to my original question but unfortunately the line pressure test didn't make any difference. I spoke to MV automatics and also took it down for him to have a look at it and of course it did everything it was supposed to. He suggested it sounded like a solenoid problem so i replaced both the shift solenoids. Now it seems to change ok but i can be cruising at 100 or so and all of a sudden it seems to neutralise and if i give it more throttle will change back to second but will not change up until i back off a bit. Does the ecu need both speed sensors for the trans to work or only the front one. The reason i ask is coz i have disconnected the rear one and have connected an external sender for my electronic speedo as the stock one wouldn't work with my speedo (TPI). Any ideas???

 

[sideshow]

what 1uz do u have

on the auto there is a front converter speed sensor 2 wire
then near the rear there is an output shaft speed sensor 2 wire
u need both of these otherwise u will have probs

then u might have 1 or 2 other speed sensors 3 wires
these are for the speedo so u have to use these somehow and not the 2 wire ones

make sure both the 2 wire speed sensors are pluigged in

if u have a crown 1uz and auto u also need a 4 pulse or and 8 pulse to the ecu depending which way u go or which signal u use

 

[Sudsy]

Thanks for the reply sideshow. The motor and trans were out of a Celsior. The wires i used were off the 3 wire speedo sensor.