PurpleDinosaur Posted November 26, 2006 Share Posted November 26, 2006 This has got to be the best place to ask this question. If you don't already know, im one of the odd balls on this site, i race a 93 hardbody with an 86 300zx vg30et engine in it. The 86 300zx I stole the engine from was a manual transmission, so was my truck. Now i've had to switch to an automatic tranny and I have a problem. I dont have the electronics in my wiring harness to properly run it. It works, dont get me wrong, but not like it should. The torque convertor doesn't lock up untill like 3500 or something, and first to second is electronic, i think. anyway i think it starts out in second gear. It still gets me down the track in the 13's at 100 mph, but i know i should be in the 12's. Besides it heats the tranny up somethin awful and because of this problem I will now be purchasing my 3rd automatic transmission. Is there any way to rig,splice,change the wiring in the factory manual 300zx harness to make an automatic tranny work? Do I need to switch ECU's? Is there anyway around this. An older transmission perhaps?HELP!!! Quote Link to comment Share on other sites More sharing options...
mtcookson Posted November 26, 2006 Share Posted November 26, 2006 I believe there should an a seperate ecu for the auto tranny to control it. To run an auto you would need the tranny computer and an auto tranny engine ecu. They say you can put an auto ecu on a manual but not vise versa. Quote Link to comment Share on other sites More sharing options...
Alex_V Posted November 27, 2006 Share Posted November 27, 2006 I would assume you could get a auto wiring harness and auto computer from some one parting out an auto car pretty cheap, thats pretty much all youd need id assume. You might need an auto ECU but being your turbo you'd have to chip it. I didnt read your entire setup, do you have a chip on there now? Id dig out an auto 300zx FSM or hardbody FSM and see if they are seperate systems, or if they can be run independant. ~Alex Quote Link to comment Share on other sites More sharing options...
PurpleDinosaur Posted November 28, 2006 Author Share Posted November 28, 2006 Well, somebody answer me this cause im stupid I guess, Did they make TURBO z31's with an automatic transmission, or were they all manual? I know some of the older nissan/jatco transmissions were vaccuum shifted. And that solves the electronic problem, but what happens when your transmission attempts to shift and your under BOOST? I have the automatic transmission TCU and the wires from it to the tranny, I just don't have a plug to use from the harness to the TCU. My setup is this, 1993 Nissan hardbody/D21 1986 Nissan 300zx Turbo 1996 Infinity 4 Speed Automatic transmission Toyota Supra Intercooler HKS BOV, (leaks after 10PSI) Stock Rear Stock Engine, I have done nothing else to it, that is it. Basicly took the engine out of the car, put it in the truck, intercooled it, and turned up the boost to 10 PSI. It weighs 2863 LBS with the driver. Runs 13's in the quarter mile with 17 inch street tires, would run 12's with the transmission problem fixed. Anyway I found this site that makes an aftermarket TCU for nissan transmissions, that you can control with a laptop computer, and all you need to send it is a signal from your TPS and a signal from you Tach. Does anyone know anything about this company. They are called Powertrain control solutions. this is their link, check em out http://www.powertraincontrolsolutions.com/content-4.html THANKS FOR YOUR HELP Quote Link to comment Share on other sites More sharing options...
NissanSportMag(Z31) Posted November 28, 2006 Share Posted November 28, 2006 Yes. There were a lot of automatic Z31 turbos. And the automatic Z31s were all electronic, not vacuum shifted. And yes. The transmission control unit will need a signal from a different TPS. The TPS found on MOST Z31s is just the standard on/off type. The Automatic and 88/89 California models also included a seperate harness for the computer. This does have a variable signal. Apparently, this type of TPS is also found on a few different Nissan cars. I've heard you can use them from Stanza's, 240SX's, etc. So your old KA TPS might also have that extra harness on it. You can download the 1986 Z31 FSM from http://www.carfiche.com to help in your transmission/ECU wiring. I'm not sure how different it will be from your Infinity trans though. Quote Link to comment Share on other sites More sharing options...
mtcookson Posted November 28, 2006 Share Posted November 28, 2006 The 89-94 Maxima's have a TPS with the seperate harness for the full reading. I'm pretty sure they'll bolt right up as they look exactly the same. Its been a while since I've seen my Maxima stuff so it could be slightly off... but I don't believe so. Quote Link to comment Share on other sites More sharing options...
premo-s12 Posted December 5, 2006 Share Posted December 5, 2006 if you need an ECU i have one off an 85 Turbo (auto). email me tho as i dont log on to this site to often Quote Link to comment Share on other sites More sharing options...
randy 77zt Posted December 5, 2006 Share Posted December 5, 2006 a 96 infinity trans would be on a car with obd2 emissions-mucho electronics needed i would guess.some kind of laptop programmable control would be the best bet.later trans have all kinds of computor controlled parts-like line pressures,torque convertor lock-up,many solonoids on valve body,turbine shaft speed sensors,fluid temp sensor.some trans use the od to split ratios -that is how some late model cars are getting 5 to 8 gears out of auto trans.since i used to work on fords i now some of the fords you can feel 5 or 6 shifts becuse of computor controlled shifting. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.