The problem: When the key is turned on the fuel pump doesn't run ( whirly sound) and the bike won't start. I've discovered the br/bl wire on the fuel cut out relay field coil leading to the ECM has 10.5 volts on it , as measured from relay terminal to ground .
When I ground this wire the fuel pump runs as long as the wire is grounded. I've swapped relays with known good ones it's definitely not the relay. There are no stored ECM faults, ignition and run switches are fine.
*I fear this suggests I have a bad ECU!
*
Before I spend big bucks on one of these I could use some help with ruling out any other conditions that might cause this problem or prevent the ECM from pulling the br/bl wire low.
*
I'd like to understand
*
1) What shuts the pump of when the key is first turned on . ( ECM timing function I presume?)
*
2) Does the pump run continuously when the engine is running? With the engine is running, on my bike if I remove unground the br/bl while hile idling the bike runs 10 seconds max and gradually dies from fuel starvation
*
3) Could there be any other inputs to the ECM that prohibits the br/bl wire on the fuel cut out coil from being pulled low?
*
4)There's another br/bl wire that runs from the fuel pump (black connector) to the instrument cluster. What does this do? I've read its used to drive the instrument cluster. If so what voltage might I expect to read on this wire?
*
Any help would be greatly appreciated
*
Regards
Joel Spano
Rochester NY
585-355-8366
When I ground this wire the fuel pump runs as long as the wire is grounded. I've swapped relays with known good ones it's definitely not the relay. There are no stored ECM faults, ignition and run switches are fine.
*I fear this suggests I have a bad ECU!
*
Before I spend big bucks on one of these I could use some help with ruling out any other conditions that might cause this problem or prevent the ECM from pulling the br/bl wire low.
*
I'd like to understand
*
1) What shuts the pump of when the key is first turned on . ( ECM timing function I presume?)
*
2) Does the pump run continuously when the engine is running? With the engine is running, on my bike if I remove unground the br/bl while hile idling the bike runs 10 seconds max and gradually dies from fuel starvation
*
3) Could there be any other inputs to the ECM that prohibits the br/bl wire on the fuel cut out coil from being pulled low?
*
4)There's another br/bl wire that runs from the fuel pump (black connector) to the instrument cluster. What does this do? I've read its used to drive the instrument cluster. If so what voltage might I expect to read on this wire?
*
Any help would be greatly appreciated
*
Regards
Joel Spano
Rochester NY
585-355-8366
Attachments
-
142.2 KB Views: 35