2G MFI pin not grounding at ECU

[MattiaFTW]

So I'm doing a weird probably stupid swap. But now i have the problem that if I turn the key there is no click whatsoever at fuel or mfi relay. No check engine light and prob a turned off ECU. Now i managed to find the the reason. If I manually ground it bij putting a cable from the Blue cable to chassis at the mfi relay ( from pin 2 of the left relay in the picture, to the chassis) It does indeed click and check engine light turns on and so the ECU is turned on. How is this possible and what is the fix to just turn ECU on by turning the key.

Thanks for all the input
Mattia

You must be logged in to view this image or video.

 

[steve]

Make sure that the ECU has 12v backup power on pin 80 and that it sees the ignition switch provide 12v to pin 82 when switched to run or start.

It's always possible that the transistor that pulls pin 38 low is blown due to a wiring error. If they get connected directly to a power feed without the resistance of a relay coil the transistor trys to empty the battery and doesn't live long in the attempt.

But check the normal functions first.

 

[MattiaFTW]

Thanks for the reply Steve. Found out the ECU doesn't get the backup power it needs. So yep that probably the problem here. Anyone a wiring diagram or idea why it gets no backup power. Is it an idea to just wire a 12v from battery to it?

 

[luv2rallye]

Test the "Room Lamp" fuse: https://www.dsmtuners.com/threads/1...-fuse-draining-battery.424216/#post-152856627

 

[MattiaFTW]

I did. Nothing wrong with it. Room lights work. No problem with the fuse. Just the power supply wire. Even if i supply 12 v to pin 80 the mfi won't click.

 

[luv2rallye]

What year and is this a 2.0 turbo, NT, or 2.4? Did you do everything in post #2 including checking for power on ECU pin 82 with key on? Then try swapping ECU if possible.

 

[MattiaFTW]

Not possible to swap the ECU. It's a stupid swap. Have a 4g63t 2.0 at. In a 1996 euro GS. Use the trans of the euro GS cause it's a Manual. And use the at harness cause if i don't i miss lots of connectors on the other harness. Nothing seems to work. Car cranks if i directly hold it on battery. Mfi switch only works when manually grounding and no spark or fuel whatsoever.

 

[luv2rallye]

So are you saying you have a USA type Mitsubishi 2g turbo ECU (what year?) with a 1996 European NT engine (or is the euro GS a turbo - I'm not familiar with it)?

 

[MattiaFTW]

I have a 1996 GS euro n/t. In the car is a Japanese import 1998 4g63t auto trans. But the auto trans is switched with the 1996 manual one. So everything is 1996 except the engine itself and the auto trans harness. Those are both 1998

Got the cel to turn on and mfi as well. Just put a test wire from ignition into pin 82 (ignition ig) this means I got bad connection between those 2. Still no spark. Keep u guys updated

 

[MattiaFTW]

After a lot of stupid modifications got it to work almost how it should work. If people are interested in a full description let me know and I'll write one.

 

[steve]

If people are interested in a full description let me know and I'll write one.

Yes, please. It might help someone else out.

 

[Talon_Man]

After a lot of stupid modifications got it to work almost how it should work. If people are interested in a full description let me know and I'll write one.

Sure haveing same problem

 

[MattiaFTW]

Damn that's a long time ago. But i remember i shorted a wire from the ecu to the ignition cylinder. If i remember i can give you full description later today.

 

[RubyEclipse]

Damn that's a long time ago. But i remember i shorted a wire from the ecu to the ignition cylinder. If i remember i can give you full description later today.

I just did the same, shorted a wire from the CAS to the ECU, car won’t start. No ignition turn over or anything. I hear my fuel pump whir and spin, but no even trying to start. How’d you fix your issue if you shorted it out?