hi my jap 300zx auto goes in to 3rd then wont cog, or just doesnt go in to 3rd at all, just revs high and doesnt pull, any ideas?

hi my jap 300zx auto goes in to 3rd then wont cog, or just doesnt go in to 3rd at all, just revs high and doesnt pull, any ideas?

 

is there any nasty whirrng noise when your in gear?has it just started doing this or was it gradually getting worse?does it change into other gears smoothly and pull ok?

it is very powerful 1 and 2nd are perfect but as soon as it should be changing into 3rd it sounds like its hitting neutural and changing back down but just revs high and redlines

I have found a thread with the same problem

 

http://300zx.co.uk/forums/showthread.php?t=124009&highlight=automatic+gearbox+problem

 

Were do i go from here does the box have its own ecu? if so how can it be tested?

The box does have its own ecu next to the main ecu.

I've just had the leaking nearside targa problem which drips onto the connectors, two of my wires had come away which gave the problem of taking ages to change up, and O/d not working, it also shunted into gear when it did finally change. Hardwiring did thetrick for me..

Auto box gear slection is done by shift solenoids, this can fail but rarely do, gear drivce clutches do though, usually the gear is in fact has selected correctly but the clutch fails to engage, this can be seen on the ConZult as the gear selects and the line pressure changes but no drive change occurs.

 

Although some odd electrical or bad fluid/filter issues can cause some issues, sadly 99%of the time it means internal gearbox problem, get it checked with a ConZult to be sure, will save you loads of time meassing about.

 

Jeff TT