2G Fuel Pump relay location?

[Bennji Favelle]

Hey all,
My car died again the other day (finally bought a BCAA membership for this car)
When I got it back to my shop I tested the wiring going into the fuel pump with a multimeter and it is not getting power.
So my assumption is that the fuel pump relay stopped working. Can someone let me know where it is? Hopefully with a pic?
Or if there is a fuse that could have blown?

[Bennji Favelle]

Bump
Anyone know where it is?
Seems like something someone would know . . . cause in my research I have found a lot of people bypassing them to give higher voltage to their pumps.

[Ryan Singh]

You might find it here:

http://www.vfaq.com/index-main.html

[Travis Koch]

1G's are under the stereo head unit..... try there.  Or just trace the wire backwards.

or Google.

[KevinBuckham]

Second google link:

http://www.dsmtuners.com/threads/mfi-mpi-relay.263224/

[Brett Haviland]

remember that stock DSM's dont send power to the fuel pump untill it sees a crank signal from the cam sensor.

check for power while the engine is cranking if u havn't already.

[Brett Haviland]

And on 2g's the MPI relay box is also up near the ecu.  I believe its the ecu as well, that turns on the mpi relay.

[Bennji Favelle]

Thanks Brett,
I didn't know that, I will hook the multimeter up again and give that another go.

Most things I have read up on show under radio passengers side, I pulled that panel again today to look more, and still found nothing there . . . Could be cause mine is a Non-turbo 420a that I am having such a difficult time with this . . . I'll try testing power while cranking, but if that still doesn't work, I might just have to run a new relay and rewire it.


I just don't want to spend 2 hours doing that, only to find that it is the pump, not the power or relay.

[Brett Haviland]

Ahhh, okay a 420a. The 420a uses a chrysler engine managment instead of the mitsubishi ecu sensors.  All the 420a stuff is similar to the neon.  With that being said, i think the fuel priming is the same as a dsm (power to pump only while cranking or running). 

 What year? i can help you get some good wiring diagrams for your car.  the 420a cars differ slightly between the years. for a 1996 420a car, it says the fuel pump relay is located "left side of safety wall".  This would put it mounted to the drivers side of the firewall (engine bay side).  If i remember there is a few relays there for various things.  The fuel pump itself says it grounds to a connection at the "front floor crossmember"  The ecu (ecu is located in the engine bay, drivers front)activates the relay on the white red wire (grounds out a IGN + signal (black/white wire)  the fuel pump relay gets its power for the fuel pump from the red/black wire which power comes from a fuse in the engine compartment fuse/relay box.

[Bennji Favelle]

Thanks for the help, it is a 95.

[Bennji Favelle]

I found where the Fuel Pump Relay is on the 420a. (See picture below)



I replaced both relays, and still no prime at fuel pump.
As per suggestion by Brett Haviland, I tried watching my Tach while cranking, and it does not move (that I can see)

Anyone got any other theories? Or Suggestions?

[Brett Haviland]

You have tried to pull any codes? if no codes....

Check for Fuel Injector Pulse, and Spark.  Also confirm the engine has good compression on all cylinders (you can usually hear this while cranking)

check the supplied powers and grounds at the fuel pump relay.  should be two powers, and two grounds... (one will only be grounded when the PCM does so) 

If that checks out (which it seems the relays are not being commanded on by the ECU)  would check for power/grounds/signal also at the camshaft sensor for a starting point.  i believe there is a 8v power on one wire (from ECU) and also a gound wire (grounds at ecu as well) an there will be one other wire.  If powers and grounds test out okay, well then i personally would use a ocilliscope to see how the pattern of the cam and crank sensors look and check out the VSS for a short as well.  If you dont have a ocilliscope, you may be able to see the high/low voltages change on the signal wire with a digital multimeter. 

  Do you have a haynes or wiring diagram?  this will really help out a ton!

[Bennji Favelle]

After replacing Fuel Pump Relays, and both Cam shaft position sensor, and crank shaft position sensor, I replaced the ECU, and voila, my car starts up again!!


Probably won't be insuring it for a while . . . but at least it is running again, so it's time to get back to work on the rest of it.
. . . . well . . . maybe I'll throw plates on it for a week or so . . . we'll see.

[Brett Haviland]

did u know which of those things ended up fixing it?   my guess is cam sensor knowing those 420a's well...

[Travis Koch]

it was the ECU obviously.