240zt swap question

[pshepard327ci]

hey all, ive been trying to figure out my problem on my l28 turbo into 240, i havent been able to get it started yet. first question i have is when the ecu is powered on, i measured voltage across + - terminals of coil, i get like 3.4 volts or something whcih doesnt seem right, i havent been able to see cranking voltage because im by self. other problem is i dont hear my injectors clicking and dont smell any fuel from engine turning over. i do not have the turbo fuel pump just the one i was using on l24, was hoping to get it at least started with that then upgrade when it was ready to drive, will the injectors fire with such little pressure. oh and do i need the green relay that says e.g.i that is right next to plug 3. on zhome.com it said if it was cut just run b/w wire to power ignition!? thanks for any help, im kinda stuck at this point, im getting very anxious to hear the motor run...!!!

 

peter

[Tony D]

What kind of pump did you have on your L24 before?

You need one capable of 40psi to run the EFI system.

 

 

 

If you are not using the power transistor to tirgger the coil as it was in the ZXT, it will never work.

 

 

Both of these may be the cause for you not getting any fuel, as without a spark timing pulse, the ECU will not supply fuel. But if you are not using an EFI pump, you will getno fuel anyway spark or no.

[pshepard327ci]

i am using the zxt coil with transitor, and i believe i have it all hooked up correctly, the yellow/white on (-) and black/white on postive, then blue on - of coil, and black on + of coil. And about the fuel pump, it is just a regular pump for carbed car, where should i go to pick up a pump. will that walpro that is like 70 bucks on holley website work or do i need to change return lines, if it wont work with stock lines i need to find a stock pump. Any one have one for sale!?!?

 

thanks,

peter

[datsunan]

First of all don't be to hasty to get your car to run you'll run into more problems than you have now. You should have 12v at the coil your problem is that you need the blue wire to + and black to neg, at least thats how my car runs with it. Check Summit racing or cheeper yet your local recking yard. The pump must be for a efi car and if you get it out of a car that you know has the same or more hp than you are running than it should be suficient. your pump needs to be capable of 36 psi at idle and 1 psi for every pound of boost you will be running ie 6psi boost =42 psi of fuel. Hope it helps take your time you'll get it.

[mobythevan]

oh and do i need the green relay that says e.g.i

 

Yes you need it, that is the relay that fires the injectors. If you don't have one or can't find one let me know, I have one laying around that is good.

[pshepard327ci]

thanks for the help, i will see what i can find at a wreking yard as far as fuel pump goes. i do have that green relay, just need to re-wire it up. thanks for the help, it really helps being able to ask someone if something is right rather than break stuff .... thanks

[mobythevan]

sorry, i didn't explain good. the green relay gives voltage to the injectors all the time when the key is turned on, but the ECU fires them. So I suppose you could just tie the wires together like the zhome article says.

 

If you have the relay, probably easier to just wire it in.

[Tony D]

the 240Z vapor return line will work as a return line, the stock one is too small.

You can route the stock fuel pressure regulator return barb right over the side of the intake and J-Pipe to go to the vapor return line. You will have to hook the return line back at the tank to one of the 1/4" barbs, and use the stock return line as a vent (has to come higher than fuel level, then loop back outside the vehicles' interior.

If you are using the stock tank, you can use the stock pickup line and filter to fill the sutre tank for the EFI pump up front, but an electric pump is better.

If you are using a 75 to 6/76 280Z tank then you can simply return the vapor line to the stock return fitting on the 280 tank.

 

Hope this isn't confusing you at all. If you are planning on going high horsepower, you may want to get a Porsche 944 Turbo pump, or high-flow Walbro as referenced in the archives of this site.

 

Those are the biggies concerning the fuel system on a 240 Z. On a 260 or 280Z the return line is fine, but the 240Z's line is too small and will have you running rich as hell if you try to use it!

[Guest bastaad525]

the 240Z vapor return line will work as a return line' date=' the stock one is too small.

You can route the stock fuel pressure regulator return barb right over the side of the intake and J-Pipe to go to the vapor return line. You will have to hook the return line back at the tank to one of the 1/4" barbs, and use the stock return line as a vent (has to come higher than fuel level, then loop back [i']outside[/i] the vehicles' interior.

If you are using the stock tank, you can use the stock pickup line and filter to fill the sutre tank for the EFI pump up front, but an electric pump is better.

If you are using a 75 to 6/76 280Z tank then you can simply return the vapor line to the stock return fitting on the 280 tank.

 

Hope this isn't confusing you at all. If you are planning on going high horsepower, you may want to get a Porsche 944 Turbo pump, or high-flow Walbro as referenced in the archives of this site.

 

Those are the biggies concerning the fuel system on a 240 Z. On a 260 or 280Z the return line is fine, but the 240Z's line is too small and will have you running rich as hell if you try to use it!

 

 

Depends if he sticks with a stock pump or not. My fuel pressure was fine using the very small stock return line on my 240, when I was using the stock turbo pump. When I switched over to the MSD pump (MSD part #2225, a good alternative to the walbro pump, a little less capable, a lot less money) my fuel pressure jumped up to 60psi and the car ran like crap. Then I figured out to do exactly as Tony D suggests and switch the vapor and return lines and no problems since. I dont use the stock pickup, rather, I run my pickup off of the fuel drain at the bottom of the tank... didn't think I could use the stock pickup?

 

 

And man I am HATING that damn green relay... keep having all kinds of problems with the wiring or maybe the relay itself I dunno but it keeps cutting out on me and causing my car to surge or even die, usually on the freeway!