Electrical Problems - No EFI

Sapar · 08-10-2010, 06:16 AM

Hi all.
Been here alot to generally find help on all my problems but I cannot seem to find the answers anywhere so I am posting. Hopefully someone can help.

First of all my car is a JZA80 Supra MkIV 1994 with a 2JZ-GTE in it.

Just did a rebuild (bottom end, left heads on), and I cannot get the car to start. It cranks fine, but I do not hear the EFI relays or fuel pump when I first turn the key. Also no check engine light.

And I have plugged in ECU and most things ect... Though I might have missed somthing so feel free to point out the obvious.

Here are 2 things that may have had an impact.

1. Shorted the imobilser/alarm (mongoose M80). I replaced the fuse that blew and now the doors and started and fuel pump cut off function normally. I may have missed another fuse?
2. Shorted the +'ve battery terminal to earth briefly when doing up the battery strap (knew I should have been more careful, but I was excited to get my car going again

) Did not find a blown fuse.

Things I have tested.

Fuel pump -> jumped it with a battery and it runs.
Fuel pump ecu -> tested power comming in. No volts on the main power. do have 12 volts on the fuel gauge.

Checked all main fuses (all of them) and relays (EFI main and EFI 2) (main fuse box in the engine bay).
No power to EFI relays on the resistor side. There is power from the +'ve fuse terminal in the fuse box itself.
Checked earth from +'ve fuse terminal to engine and to chassis and get 12v

Thats as far as I have gotten so far.

I do plan to
: check the power to the EFI fuse
: check the power to the ECU input

I also want to check the 7.5A IGN fuse that is in the wiring diagram, but I can't for the life of me find it. Checked under the steering colum and kick well of the driver, So if someone could give me a general location that would be great.

I am still a bit suspicious of the imobilser cutting the power to the ECU.

I am aware that I still have to do some more testing before I can find the exact problem but if anyone has had these problems before and can give me some more things to test or simple things to check would be great.

Thanking you in advance for your help!

08-10-2010, 06:16 AM	#1
Sapar Stock Join Date: Aug 2010 Location: Perth Posts: 8	Electrical Problems - No EFI Hi all. Been here alot to generally find help on all my problems but I cannot seem to find the answers anywhere so I am posting. Hopefully someone can help. First of all my car is a JZA80 Supra MkIV 1994 with a 2JZ-GTE in it. Just did a rebuild (bottom end, left heads on), and I cannot get the car to start. It cranks fine, but I do not hear the EFI relays or fuel pump when I first turn the key. Also no check engine light. And I have plugged in ECU and most things ect... Though I might have missed somthing so feel free to point out the obvious. Here are 2 things that may have had an impact. 1. Shorted the imobilser/alarm (mongoose M80). I replaced the fuse that blew and now the doors and started and fuel pump cut off function normally. I may have missed another fuse? 2. Shorted the +'ve battery terminal to earth briefly when doing up the battery strap (knew I should have been more careful, but I was excited to get my car going again ) Did not find a blown fuse. Things I have tested. Fuel pump -> jumped it with a battery and it runs. Fuel pump ecu -> tested power comming in. No volts on the main power. do have 12 volts on the fuel gauge. Checked all main fuses (all of them) and relays (EFI main and EFI 2) (main fuse box in the engine bay). No power to EFI relays on the resistor side. There is power from the +'ve fuse terminal in the fuse box itself. Checked earth from +'ve fuse terminal to engine and to chassis and get 12v Thats as far as I have gotten so far. I do plan to : check the power to the EFI fuse : check the power to the ECU input I also want to check the 7.5A IGN fuse that is in the wiring diagram, but I can't for the life of me find it. Checked under the steering colum and kick well of the driver, So if someone could give me a general location that would be great. I am still a bit suspicious of the imobilser cutting the power to the ECU. I am aware that I still have to do some more testing before I can find the exact problem but if anyone has had these problems before and can give me some more things to test or simple things to check would be great. Thanking you in advance for your help! Last edited by Sapar; 08-11-2010 at 05:27 AM.