1jz auto to manual conversion, speed sensor and neutral start switch

johnd-mkiv

New Member
Jul 12, 2010
14
0
0
Essex
I have a auto 1jz loom and ecu with a 5 speed r154 conversion put into an m3 bmw< I have the car running but around 4000 rpm its cutting and spluttering< I have changed the coil packs plugs and ignitor for known good ones and stil the same problems, on researching I have found the following

"with some auto to manual conversions i've done, you'll find you do need those wires, as when you flatten the throttle, and take off up the road, your ecu sees massive load, revs, but no speed as the speed sensor (which is one of the wires to the auto) isn't hooked up, and pretty soon it'll stop the fun, leaving you with an annoying cut out, much like a boost cut. whether this is the case or not for your setup i'm not sure, but i'm pretty sure you'd be better off to grab a manual computer, or figure out some way of 'sensor bending' that sensor (tricking the computer into seeing there is some load, enough to stop the 'cut')."

I have the autobox wires unattached in the engine bay< the neutral start switch must be bypassed further up the loom by the auto electrician as the car runs and drives< but the speed sensor has not been touched< does any one know of a mod to confuse the ecu into this being connected or is it best to leave disconnected as this is not the problem??
 

johnd-mkiv

New Member
Jul 12, 2010
14
0
0
Essex
New update, the engine warning light now comes on after calibrating the tps it picks up in the higher revs but still splutters, before doing the tps no engine light come on i have tried the manual diagnostic check and its showing up code 42 which on looking in the manual is the speed sensor signal.
Im going to try this mod in hope this will cure it, http://www.supraforums.com/forum/sho...d.php?t=349732

i can find the speed sensor wire its just the vss input wire im unsure of. I have an ecu pin out with the speed sensor listed as T8 pink wire & T7 is a blue and red wire that runs up to the grey square block that I guess would have gone to the dash, this is listed as being a/c signal from a/c ecu to engine ecu> would I be correct in cutting these two wires an the ecu and soldering them together to complete this mod. I am running a seperate speedo for this car

Detailed picture of dashboard plugs the on I believe is the big square plug number 9
http://www.supras.nl/index.php?optio...d=38&Itemid=54

ecu pin out picture
http://www.google.co.uk/imgres?imgur...ed=0CBsQ9QEwAA

Your help will be greatly appreciated

John