2G MFI/MPI Relay

[kahl23]

I know a lot of guys are trying to find the MFI/MPI relay, here's where it is and what it looks like on a 95 GSX.

 

[90TSI717]

alright thanks man. i spent a few more hours searching and someone mentioned that the crank angle sensor (CAS) is the best way to do it on a 2g. i know it is located somewhere around the fire wall. by unpluging the MPI fuse, will this eliminate all spark and cut fuel? i just dont want to see an engine with 2,500 miles go. also, will it throw and codes that i have to clear or restart the ecu? and thanks i was thinking 10 cranks and wait 10 seconds around 4 to 5 times. after i get enough oil pressure, would it be a good time to look for any leaks, or should i start the car and check?

Like Steve said, pulling the MPI fuse will shut off the ECU so there will be no fuel/ spark. If you do unplug the CAS, it will throw a trouble code which will need cleared either by resetting the ECU or by way of a tuning device like ECMLink or just a simple OBDII scan tool. That is why I suggested just pulling the fuse so there will be no trouble codes. You should start the car to make sure both oil and coolant lines show no leaks. Obviously if you prime the turbo and oil shoots out, you need to fix it.

 

[eburg2490skillz]

thanks a lot guys! i dont want anymore work than what i have to. i am doing this alone to really understand my car so i can have more "under the hood" experience in the auto world. plus a check engine light at 1500 miles on the trans, engine and clutch is just embarrassing haha

 

[954g63gst]

What pins would I check on a 95 GST. I believe my MPI is malfunctioning or my ECU. Its one or the other cause the other relays work and my check engine light doesn't come on when my key is in the on position before I crank it.

 

[JFZERO ECLIPSE]

If the cel does not pop up and go off after roughly 5 seconds.... Check the ecu first.... That's where I would put my money...

 

[luv2rallye]

What pins would I check on a 95 GST.

http://www.dsmtuners.com/forums/tun...-power-mpi-mfi-relay-issue.html#post152387614

 

[954g63gst]

https://mail-attachment.googleusercontent.com/attachment/u/0/?ui=2&ik=87f173664d&view=att&th=13f4d2871b0c2dd1&attid=0.1&disp=inline&safe=1&zw&saduie=AG9B_P_J0-19sR5bsjhgjw9zyV3O&sadet=1371389104278&sads=k1zsEMzVZ3AOodXGzBmHshWIWYQ&sadssc=1



This is my ecu appears good. My fuel pump turns on and my starter clicks but does not spin. I ruled out clutch switch and starter relay and the one by the starter relay. its the MPI/MFI that clicks after the pump turns on and the starter clicks once. how do I test the MPI/MFI relay while its plugged in? sorry I just want to get the problem figured out. The car jump starts. And will continue to idle. But wont start itself. The battery checks out at 12.6. I've unplugged the clutch switch nothing changed. If I turn the key without pressing the clutch the relay under the radio clicks if I press on the clutch and turn the key the MPI/MFI clicks but the fuel pump turns on and the starter motor gear comes out but doesn't spin.

 

[Silvas1372]

maybe one of you can help me!!!! my safc2 wont turn off when i turn the car off which means the ecu isnt turning off. ive had the safc for 6 months with no problems but one day just started doing this, the car runs perfect. looked at the ecu and looks fine, no leaks. so i think its the mpi relay becuase if i hit the relay with my hand the ecu turns off!

 

[Nathan Jorgenson]

Here is what the MPI/MFI relays look like on a '97 GSX.

Same as the '95, only these are 2 separate relays and are behind that brace there, held on with the 2 bolts seen in the pic.

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

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

The relay with red wires is for the ECU. That relay brings both pins 12 & 25 up to +12 on the ECU, with key on and the 30A 'moteur' in place. Which is located - fuse box in engine bay.

When that relay is activated, the ECU is in turn, activated. Once that happens, the ECU then turns on the OTHER relay next to it for a brief amount of time, which is for the fuel pump to pressurize (prime) the fuel system when the key is first cycled to the 'run' position.

So if you pull the 30A 'moteur' fuse in the engine bay, then neither of those relays will switch on = no fuel pump because = no ECU.

After wiring in a few things and fixing the ECU wiring, I wanted to throw this out there before I forgot

Any false info, please let me know and I'll edit

Is it located in the same place for the 1g.

 

[steve]

Is it located in the same place for the 1g.

Is the 1G MPI relay located on the passenger side console support? Yes.

 

[Curtis Oney]

ps. I have some 1g MPI/MFI Relays laying around. If anybody needs them let me know. I am cleaning the garage out. (no charge)

I need one