Crank no Start (JDM BH5 Wagon)

[Justyn]

Hello guys,

 

Pretty much going to try to put as much information here so someone can help me. I did an engine swap and no the fuel pump is not coming on. I checked the fuel pump by itself to see if it would turn on and it does. So they have something wrong with the wiring maybe.

 

Things I already replaced. I replaced the fuel relay under the dash and that didn't resolve it. Was wondering if the O2 sensor needs to be plugged? I haven't received my new one yet.

 

Kinda need help with directions on what else to check.

 

Thanks!

 

Vehicle Info is JDM 1998 Subaru Legacy BH-5 Wagon Manual Swapped

Edited April 9, 2020 by Justyn

[doublechaz]

You need a multimeter, the FSM that goes with the ECU you are using, the FSM for the wiring harness you are using, and lots of time.

 

Start at the ECU and see if it is commanding the fuel pump to turn on. Then follow the wire to the other end, probably at the relay, and see if the command is still there. Check for power at the relay. Check to see if the relay is actually passing the command into the wire for the fuel pump. Follow the wire to the other end and see if it's still there. Check for ground quality even under high load.

 

You'll have to read a lot from the FSM to see how it all works and what voltages to test for. Example: the fuel pump relay turn on signal at the ECU is most likely a conduction path to ground. That pin is probably no connection for relay off and pulled to ground for relay on. In that case there will be 12 volts on that pin when the relay should be off. You would have to verify that the 12 volts is coming from a source to the relay, through the relay and to the ECU.

 

There's no quick parts shotgun for a mix and match engine swap.

[Justyn]

Alright picked up a multimeter but anyone has the correct JDM FSM?

[doublechaz]

I don't remember where I got mine, but it's for a 95 USDM NA.

 

I think there was some stuff in the sticky about various pdf downloads, but I'm not sure as I already had mine before I found this forum.

 

Edit:

 

At a glance http://jdmfsm.info/Auto/Japan/Subaru/ looks promising.

Edited April 12, 2020 by doublechaz

[giiyanman]

I got a FSM copy for AUDM 98-03 Liberty's. Basically the same as JDM but de-tuned because of Australia's lower quality gas. Let me know if you need it. This thing is 4400 pages long lol.