fl327 Posted August 22, 2004 Share Posted August 22, 2004 dont have to use 300 transistor to use the coil. its a two wire hookup, blue goes to blue wire, the green or other colored wire goes to b/w, turn the key. Link to comment Share on other sites More sharing options...
Afshin Posted September 27, 2004 Author Share Posted September 27, 2004 Addendum: in the original write up I mentioned inserting two new pins (34 & 3) which are connected to + and - terminals going to the coil. However, reading up on the MSD unit, I realized that it is sending 500 volts to the coil (yup, that much ). So for all the people who are using an MSD type unit, in order to avoid burning out any of the circuit in the ecu, you should use the original 12 V wires going to the coil (they are the two wires that feed into the msd unit) to power pins 34 & 3 and not the wires comming out of the MSD unit (500V) to the coil. Link to comment Share on other sites More sharing options...
Sean73 Posted January 15, 2005 Share Posted January 15, 2005 I would like to convert my 84 ECCS to 88 ECCS so that I can burn my own chips, and I know that the 88 ECCS uses higher impedance injectors, so I need dropping resistors. It's been a while since electronics class, so excuse my ignorance-- but wouldn't it be possible to use just ONE dropping resistor to the primary positive(+) power lead to the injectors, instead of 6 dropping resistors to 6 the negative(-) leads that go back to the ECU? The thought of making 6 splices into my neatly taped harness does not sound fun. I have tried an 88 ECU with my 84 ECCS harness, and it works fine without the dropping resistors. Would prolonged use damage the injectors? Anyone try this for an extended period of time? Link to comment Share on other sites More sharing options...
Bernardd Posted January 15, 2005 Share Posted January 15, 2005 I did it for a year with no problems. It's not the injectors, it's the ecu that can be damaged. I always had a spare ecu with me just in case. Link to comment Share on other sites More sharing options...
turbobluestreak Posted January 15, 2005 Share Posted January 15, 2005 would the stock non turbo dropping resister have enough resistance to bring the voltage down? Also are we talking about going from 12volts to 6 volts? tbs Link to comment Share on other sites More sharing options...
Afshin Posted January 16, 2005 Author Share Posted January 16, 2005 The high impedance can cause the low impedance injector coils to overheat (~12 vs 2.5 ohms) and fail. I initially used 370cc SVO injectors and after 6 months 4 out of six of the injectors failed. They overheated and started to leak between the plastic injector base and the metal core. All works great since using the resistors. JWT also instructs on using the resistors. I know Bernard's have not failed on him, but he does not run open track events were the injectors would be working at high capacity/duty cycle for a prolonged time. ALso he is using larger injectors than I initially did, so was probably running at lower duty cycle and generating less heat. I also now use 440cc injectors. It's easy enough to put the resistors in and it was no fun ruining a set of newly rebuilt SVO injectors. My guess is that the non-turbo resistors would work and I don't think that you could use one on the common positive (both oem and aftermarket applications use six). Link to comment Share on other sites More sharing options...
RacnJsn95 Posted May 4, 2005 Share Posted May 4, 2005 I am going to attempt to do this swap with my 78 280z. I think I have everything I need. I have the MAF, ECU, and chopper wheel from an 84 300zx. I have the wiring harness from an 81zx, the dizzy from an 82zxt and the shaft. There is one thing I am not sure about... I have the zxt shaft, but do I need the zxt oil pump as well, or will that shaft fit in my stock oil pump? Later on I plan on switching to a 87-89 ECU so I can reprogram it to suit my needs. Any thing else important I should know? Thanks! Link to comment Share on other sites More sharing options...
Bernardd Posted May 4, 2005 Share Posted May 4, 2005 I am going to attempt to do this swap with my 78 280z. I think I have everything I need. I have the MAF, ECU, and chopper wheel from an 84 300zx. I have the wiring harness from an 81zx, the dizzy from an 82zxt and the shaft. There is one thing I am not sure about... I have the zxt shaft, but do I need the zxt oil pump as well, or will that shaft fit in my stock oil pump? Later on I plan on switching to a 87-89 ECU so I can reprogram it to suit my needs. Any thing else important I should know? Thanks! Gotta have the turbo oil pump. Link to comment Share on other sites More sharing options...
Forrest Posted May 4, 2005 Share Posted May 4, 2005 Does anyone know what's required to reflash the z31 ECU? Link to comment Share on other sites More sharing options...
lifegrddude Posted May 23, 2005 Share Posted May 23, 2005 Hi, does anyone have a wiring diagram for a Z31? I have a Chiltons manual and a FSM for my 82zxt. My Chiltons book doesn't have a wiring diagram for the Z31 unfortunately. (maybe those pages got ripped out by the previous owner) If anyone can shoot me a pm or email me (awamori99@hotmail.com)the diagram, I'd appreciate it a lot. Thanks. Link to comment Share on other sites More sharing options...
Guest troylatif Posted May 24, 2005 Share Posted May 24, 2005 Hi, I've been looking into swapping a 300zx ecu and harness into my 280zxt. My z's actually a conversion and it currently has the 79 ecu and harness. I've heard about some people dropping the whole z31 ecu and harness into a 280zx but the information has been vague. Can anyone who'se successfully done it give a layout of the parts needed from z31 other than the harness and ecu. Also, the connection mapping because I know there are several components in the z31 that the 280zx just doesn't have some of the z31 efi components and I can't see how the z31 harness can plug into the 280zx efi parts. Thanks, Troy. Link to comment Share on other sites More sharing options...
lifegrddude Posted May 24, 2005 Share Posted May 24, 2005 n/m about my previous post, I found dacelooper's old post on zcar. I do have a problem of getting my Z to run though. When I first started it up, it ran on all 6 cylinders but after about 30 seconds of idling, it stalled and the plugs were fouled. I tried to adjust the screw on the side of the maf leaner, but it didn't help. Even after putting in new plugs my Z will only fire on about 1/2 the cylinders and I have to keep the gas floored to get it to idle. I'm going to take a look at my wiring to see if maybe I screwed up somewhere along the way. Also, my tach isn't functional, it just jumps around as if I've added an aftermarket ignition box. I'm running 370's at the moment and my Walbro pump is wired to a kill switch, would that mean I have to still do the pin swap on 108 and 16? (I have done this, but I'm curious as to if it is actually needed) I did notice that with an a/t ecu on my Z (a/t as well) my ignition will shut off when the key turned off. When I tried a m/t ecu, the ignition would shut off once on. I had to pull the bottom plug out to shut the car off. Anyways, any help or advice on cracking these problems will be appreciated. John Link to comment Share on other sites More sharing options...
Afshin Posted May 24, 2005 Author Share Posted May 24, 2005 Dave, aka dacelooper has some nice diagrams and pictures of the ecu plugs... that are very helpful. He was nice enough to poste a link on the second page of this thread, somehow people keep missing it. I would advise that anyone attempting this read all the posts carefully as important info was added from the time I wrote the first post. John, you will flood and foul the plugs with 370cc injectors unless you have the ecu reprogrammed. Adjusting the screw on th MAF won't cut it (you would need a much much larger air bypass than the small hole on the MAF). Put back the original injectors for now. ALso, since the VCM will no longer work, you will need to adjust the throttle body stop screw to adjust the idle up (the throttle body plate needs to be further opened for proper idle with the Z31 set up). Regarding pin 108/16, that is to turn the fuel pump relay on and off, if you have a different set up to turn the pump or relay on and off than you don't need it. Link to comment Share on other sites More sharing options...
lifegrddude Posted May 25, 2005 Share Posted May 25, 2005 Thanks for info, it took a while to get everything sorted out, but now the car runs. I haven't taken it on a test drive yet, however it revs freely without sputtering. The only thing I have left to solve is the ignition. I can't get it to turn off unless I yank out the bottom plug on the ecu out. I guess the m/t ecu's have a slightly different setup than the a/t Z's. I'll look into this a bit later since I have to start up work again tomorrow. Anyway, thanks again for the writeup Afshin, it definitely made the swap 100x easier. John 82ZXT Link to comment Share on other sites More sharing options...
Afshin Posted May 25, 2005 Author Share Posted May 25, 2005 I don't know why your ignition won't shut off, but the automatic and manual ecu have the same pin configurations, so the answer is somewhere else. Also the wires related to this are the same for the 280 and 300zx, so the swap, if done correctly should not affect the turning on and off function. Check out the diagrams.... if I remember correctly, pin 6 is the power source coming from the EFI relay that turn the unit on and off and pin 114 is the constant main power source. Link to comment Share on other sites More sharing options...
tay-fu300zxtt Posted July 6, 2005 Share Posted July 6, 2005 Does this only work with a 1983 280zxt OR 1983 harness, because i have a 1982.. Link to comment Share on other sites More sharing options...
Afshin Posted July 7, 2005 Author Share Posted July 7, 2005 There should be no difference. Link to comment Share on other sites More sharing options...
tay-fu300zxtt Posted July 7, 2005 Share Posted July 7, 2005 thanks man Link to comment Share on other sites More sharing options...
twistex Posted August 28, 2005 Share Posted August 28, 2005 ok i have a diesel maxima block and crank bored and stroked with gas head. cam ported head big valves, springs, knifedge crank long rods.. everything basically. i have a tripple carb manifold but i ported out my injection manifold and adapted a 65mm tb on it and put 280zxt injectors and a fuel presure regulator. well i wana run a new computer system . i had this setup in a 84 maxima and got tired of it not running right with that shitty flap maf. i wana wire in a z31 harness and maf. anyone know how hard that would be ? or would i need to put in a 280zxt harness first ? please help car is all ready to go.. harness is last thing! Link to comment Share on other sites More sharing options...
Nismo280zEd Posted September 4, 2005 Share Posted September 4, 2005 I'm curious as to if I can run the ZXT harness on my 78 280z. I would like to use the MAF and not the AFM, lowering the impendance to the injectors I don't think should be that big a problem. Any Thoughts? -Ed Link to comment Share on other sites More sharing options...
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