Mitsubishi 3000GT & Dodge Stealth Forum banner
1 - 9 of 9 Posts

·
Registered
Joined
·
15 Posts
Discussion Starter · #1 ·
So Im not getting ground to my injectors on my 1994 3000gt vr4.

Is my ECU bad?

I connected my obd2 and says it no communication..

does anyone know what I should do.. car wont start
 

·
SDSU Alumnus
Joined
·
4,201 Posts
Is your MFI relay functional? Does the CEL cycle on/off upon keying on? FYI, your scanner will likely not work on a "hybrid" ECU.

Also, how are you testing them? Lab/oscilloscope?

-sent from my Galaxy Note 9
 

·
SDSU Alumnus
Joined
·
4,201 Posts
There is a possibility that the ECU is not receiving power. The first, simple check is the engine fuse beneath the dash. If that is not it, then I would recommend that you test the MFI relay.

-sent from my Galaxy Note 9
 

·
SDSU Alumnus
Joined
·
4,201 Posts
Search for it or refer to FSM (service manual)

-sent from my Galaxy Note 9
 

·
Registered
93 NA ATX 3000gt DOHC
Joined
·
3,444 Posts
So Im not getting ground to my injectors on my 1994 3000gt vr4.

Is my ECU bad?

I connected my obd2 and says it no communication..

does anyone know what I should do.. car wont start
Being a ’94 there’s certainly chance that a least capacitors have failed in the ECU. As @bboyalan said OBD2 reader won’t work on a ’94 or even a ’95 for that matter. Below is thread links concerning pulling codes on ’94-’95 easily found by using search bar at top of page. Also a thread with clip from FSM about testing MFI relay, both were supplied by one of our senior and capable members @OhioSpyderman. But the MFI relay only supplies battery voltage to injectors when key is turned ON, the grounding (firing) of injectors is only done by the ECU.


 

·
Registered
93 NA ATX 3000gt DOHC
Joined
·
3,444 Posts
Other than things already mentioned by @bboyalan, there’s also possibility of shorted IAC coil damaging the injector control circuit in ECU, which damage is sometimes visible when viewing ECU board and sometimes not visible, same as true with capacitor damage.
 

·
Premium Member
Joined
·
7,130 Posts
One quick test you can do that will give you a clue if the ECU is even powered up is to check for the 5V reference at the TPS.

I find almost all electrical and component tests can be very quickly done at the ECU connector. I like to just yank the ECU and toss it on the floorboard to perform all the tests. I can test injector circuits, IAC, powers, grounds, sensors, you name it...
 
1 - 9 of 9 Posts
Top