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View Full Version : Help, Busa Wiring, Need to Fire Up!



Slablocal
02-12-2009, 07:22 PM
Alrighty guys, here is the deal. I am at the last stage of this car and i need to get the thing running to go testing this weekend. It is a busa engine, there is no instrument cluster, no stock ign switch. here is what i have done so far for the wiring...

- 100 ohm resistor between the O/Y & B/W on the IGN Sw connector
- 12v switched to the Orange wire on IGN Sw
- Connected the wires on the side stand switch (Scott @ heads up said no resistor needed...)
- Siliconed the tip over sensor
- Grounded the engine/wiring harness
- Clutch switch is controlled through a toggle switch

I cant get the thing to fire up, a few things i have thought about but have not tried...

- Anti-Theft...do i need to ground this pin or anything>
- Do i need to run a switched 12v to any particular wires on ign sw connector?


Please let me know if there is anything you can think of so i can get this thing going...thanks!

Gene
02-12-2009, 08:20 PM
PM Busasandrail. He knows what to do!

busasandrail
02-13-2009, 09:57 AM
How are you getting power to the red wires in the harness?
Make sure they have power from a master disconnect or something. And make sure it does get back to the battery.

And Im not sure how you bypassed the sidestand switch but I always remove it completely. Im guessing if you jumpered it this could be the problem.

Also assuming you did but check and make sure the master power fuse on top of the starter relay is good. w/o that it wouldnt run.

One more thing does anything turn on at all .....ie fuel pump, does it turn over, anything?

let us know....

Slablocal
02-13-2009, 11:24 AM
How are you getting power to the red wires in the harness?
Make sure they have power from a master disconnect or something. And make sure it does get back to the battery.

And Im not sure how you bypassed the sidestand switch but I always remove it completely. Im guessing if you jumpered it this could be the problem.

Also assuming you did but check and make sure the master power fuse on top of the starter relay is good. w/o that it wouldnt run.

One more thing does anything turn on at all .....ie fuel pump, does it turn over, anything?

let us know....

*The red wires on the harness (reading volt meter from red wire in Ign Switch connector [green 6 wire connector]) have 12v. I believe it is being fed from the 2 red wires on the starter relay. The wires for the starter goes as follows: starter lug to starter relay, second wire from relay to alternator lug (which is on a master batt. switch)

*On the starter relay, the only wires that are modified are the B/Y & Y/G on the plug.... (Y/G was cut and run to the starter switch in the dash, and the B/Y goes to a switch in the dash that completes the ground, the "clutch switch" (used only at startup).

*The sidestand switched was jumped (I asked scott @ heads up turbo if i needed a resistor, he said no)

*The fuse on the starter relay is good. The engine will crank over, but thats it, no spark. we are running a whole seperate fuel pump on a seperate wiring loom (power is from a toggle switch in the dash) so the fuel pump relay is still in the wiring harness, but the pump is not hooked up. So I cannot hear the pump pressure up and shut off.

standfast
02-13-2009, 11:50 AM
You said you have no spark. Are the injectors firing? (pull a plug, smell fuel?) You probably need to confirm that you have 12v constant,ground, and ignition power at the ECU where they are required to confirm that the computer is even on. I am guessing you don't due to a unpatched/cut/blownfuse circuit.

Slablocal
02-13-2009, 12:05 PM
You said you have no spark. Are the injectors firing? (pull a plug, smell fuel?) You probably need to confirm that you have 12v constant,ground, and ignition power at the ECU where they are required to confirm that the computer is even on. I am guessing you don't due to a unpatched/cut/blownfuse circuit.

There is no signal going to the fuel injectors. Nothing shows up on the voltmeter, and the fuel pressure gauge does not drop pressure when cranking. No fuel smell.

busasandrail
02-13-2009, 12:05 PM
On your strater relay the B/Y not only goes to the clutch switch it also goes to the cpu ....if you cut the wire the cpu wouldnt know you where starting the motor. Double check that wire and make sure it goes to the cpu also.
Plus the Y/G wire also goes to the CPU double check that wire too.

Slablocal
02-13-2009, 12:09 PM
On your strater relay the B/Y not only goes to the clutch switch it also goes to the cpu ....if you cut the wire the cpu wouldnt know you where starting the motor. Double check that wire and make sure it goes to the cpu also.
Plus the Y/G wire also goes to the CPU double check that wire too.

So if i reconnect these wires and simply "Y" off them (for my dash switches), would that be acceptable?

busasandrail
02-13-2009, 12:10 PM
I think so......... as long as the loose ends in the harness dont short or ground out.

standfast
02-13-2009, 12:18 PM
Whatever you do just confirm the computer has power to it. Check to see if there is power there before you change anything, if not, make the change and check again. Then you will know when you got it and when to try to start it up again.

Slablocal
02-13-2009, 12:37 PM
Well like i said before, there is power at the red wire on the ign switch connector, but i don't know if that means there is power to the comp. What wire color or ECU plug should i check for power?

Slablocal
02-13-2009, 12:56 PM
What about the antitheft? anything need to be jumped or resisted for that?

busasandrail
02-13-2009, 12:56 PM
The wire to the cpu that is hot is O/W.

This wire comes from the start/stop buttons. Which in turn is feed from the side stand relay. Which you do have installed...right?

busasandrail
02-13-2009, 12:58 PM
antitheft is O/Y wire from cpu. This wire needs a 100 ohm resistor installed in series then landed to ground

Slablocal
02-13-2009, 01:05 PM
Alright, the O/Y has the resistor and is grounded, so that is is taken care of.

This O/W wire on the CPU is NOT HOT when i have this thing cranking, so i think that might be the problem. From what i see on the wiring diagram and what you are telling me, i need to get a straight 12v to the O/W? (12v from my dash IGN switch)

busasandrail
02-13-2009, 01:13 PM
the O/W wire should be a switched 12v source...meaning that when you turn on you ignition it sends 12v to that wire.....

Also you will need to hook up the starter relay wires you cut...the cpu needs to know you are starting the motor.

Slablocal
02-13-2009, 01:15 PM
The relay wires have been reconected and i basically "spliced" into them. I am going to give the O/W wire 12v right now and see what happens....dont leave me yet....savior, haha.

busasandrail
02-13-2009, 01:17 PM
Also make sure you ignition switch (if you using one) doesnt cut the power to the ignition when you turn the key to start the motor.
Some switches are set up this way.

Slablocal
02-13-2009, 09:07 PM
Busasandrail....you are a GOD!

This thing is so much fun, i have had a grin on my face ever since we got it fired up! faster than sh!^ too! thanks again busa and Standfast! I owe you one!

busasandrail
02-13-2009, 10:49 PM
:D glad I could help.