2G Calling all electrical gurus

[J Waite]

Hey guys.

I bought a 1998 GSX from out of state. And OH MY GOD what a mess.

Let me get started on my issue.

There is a a yellow wire run from the rear of the radio area thats jumped in a relay and run to the starter terminal. Disconnect and no start. Reconnect and it starts.

The MFI relay has a jumper wire and additional relay wired straight back to the pump which is a hacked together mess. Fuel level gauge doesn't work and fuel pump pressure is erratic even after swapping to a new pump. And there was a FM101 Fuel level module wired in. Id like.to just figure out what would cause the MFI relay issue.

This is my 3rd DSM but 1st AWD and im a little confused. Could it possibly be a bad ignition switch? I installed a new ecu with ecmlink v3 and still have these issues. Dont want to fry that with weird electrical problems.

Please advise.

Attached photos of yellow starter wire run out the window.

Fuel pump relay relay

And fuel pump connection area in rear

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[Justin DuBois]

Someone bypassed some stuff - MPI relay? - probably cause they could not find or could not identify a failed component. This is gonna be fun.

If I were dealing with this car - I would bust out the 2G wiring diagrams for this year and start putting wires back to stock - noting what was changed. From stock wiring, then its more normal diagnostics to find the failed component. You may need to test individual parts - like the MPI relay, FP relay, and the ignition switch.

 

[luv2rallye]

There is a a yellow wire run from the rear of the radio area thats jumped in a relay and run to the starter terminal. Disconnect and no start. Reconnect and it starts.

The relay this yellow wire hacks to is the starter relay. The black/yellow wire on the connector is the original factory wire that goes to the starter. He probably didn't know he could have used it (or it's broken somewhere) and just ran his own wire all the way to the starter. He may have wanted to just bypass the starter relay as a quick fix to get around whatever issue he had (eg. ignore clutch pedal switch, alarms preventing starter operation, didn't want to waste any more time trying to figure out why starter never works).

The MFI relay has a jumper wire and additional relay wired straight back to the pump which is a hacked together mess. Fuel level gauge doesn't work and fuel pump pressure is erratic even after swapping to a new pump. And there was a FM101 Fuel level module wired in. Id like.to just figure out what would cause the MFI relay issue.

The additional relay is probably a fuel pump rewire to handle a higher current draw and capacity after market fuel pump (https://www.dsmtuners.com/threads/2g-gs-t-fwd-gsx-awd-fuel-pump-rewire-diagram.377570/). Fuel level gauge requires both senders in both tanks to be working and their wiring intact (they are wired in series). Irratic fuel pressure might be a faulty fuel pressure regulator (on the drivers end of the fuel rail). Don't know anything about a FM101 module (aftermarket?).

 

[J Waite]

So far I've downloaded all service manuals and have begun tracing the circuits in question.

Going back as far as possible to stock and then making sure everything is correct seems to be the best option so far.

Im going to do resistance tests on the starter wire that may have been bypassed.

My issue mainly is going to be the fuel pump circuit right now. I went from a wahlbro 255 to areomotive 340 pump. And as the car runs and got warm the pump would die out. The MFI relay is still intact as shown and I have power and the rewire job that is presently there seems to only ground the wire to the pump. Im pulling both sides back out and going to resistance test the floats and make sure everything functions on a bench.

 

[J Waite]

I also failed to mention that I am running an afpr and the car came with an evil energy fuel filter and aftermarket fuel lines that were hobbled together. At that point fuel in and fuel out can be either side of the rail correct?

 

[Justin DuBois]

I also failed to mention that I am running an afpr and the car came with an evil energy fuel filter and aftermarket fuel lines that were hobbled together. At that point fuel in and fuel out can be either side of the rail correct?

I suppose it can? Supply is typically left to right on 1G and 2G - 4G63 Why would you route differently?
Keep an eye on those evil energy AN hose ends. - My oil lines started leaking at the swivels - not long after use. - Fuel line leaks would be so much worse.

 

[J Waite]

Previous owner routed it that way. After finding so many other things wrong I just made note to repair later.