Hey everyone,
I've been trying to get this bike running for a while now. I changed the crank position sensor today, hoping it would fire up. After it didn't, I cussed a bit and then went back into the wiring diagram. I wanted to run the codes, but in the instruction I found on the site, you listen for the fuel pump. I'm not getting anything. The bike will crank fine, but it won't fire. I know the fuel pump relay isn't energizing, so no fuel or ignition. I know the fuel relay gets it's ground through the ecm. I figured the ecm would have to be powered, but when I checked the ecm relay, it didn't seem to be energized. The relay gets it's ground through the ecm. I don't have a schematic of the ecm, so I can't find how the relays ground. When I first got the bike home, I looked it over, and found the wire that is the ground for the ecm relay was severely corroded. I changed the pin, and as soon as I put the relay back in, I got the fuel pump, and the bike started. It ran for about five minutes, and then died. Since then, it was hit or miss whether I would get the fuel pump. If it came on, the bike would start, but only for a short time. I replaced the fuel, thinking it was old gas. It started one more time, then nothing. I was reading that the crank position sensor could cause this, so I changed it. Is there anything else that could cause this problem? The electrician in me is saying it is the ecm, but I hope it is something a little less expensive. I apologize for writing a novel, but I wanted to get all the pertinent info down. If anyone can guide me in a new direction, I would appreciate it.

 

Brad223, based on your troubleshooting so far, I tend to agree with you on the ECM.

If you need an ECM, check this guy out. he's got everything and has it at very reasonable prices...

http://www.robsusedharleyparts.com/main.php

 

Thanks for the lead UltraNutZ. I didn't see any on the site, but I'm going to contact them. Is there a way to bypass the ground circuits going through the ecm to isolate the problem to the ecm or another component? Thanks again for your help. Brad

 

#1 )Would it be possible for you to apply power to the fuel pump directly...to bypass everything and just get the voltage to fuel pump?
Trying to isolate the problem..Rule out the fuel pump first.
#2) limited history provided on your bike (repo, found in canal, abused, auction, police?, miles, storage,condition) but: The ECM is known to develop corrosion at the terminals especially if ECM rubber boot was damaged, removed(power commander) or bike was/is pressure washed...clean the terminals really really good first.
Many ECM problems are related to corrosion orr failure to complete contact. Check negative battery cable also.

 

Hey im, the bike was in storage for about 2 years. During that time mice got up under the seat and chewed on some wires. I fixed all that. The big thing was the green wire that is the ground circuit for the ecm relay was corroded. When I found it, the pin has corroded in two. I changed the pin, and the bike started, but it didn't run long. I'll go over all the wires I have moved or touched, and clean the connections. When you say terminals, do you mean the ones in the ecm connector? What do you use to clean them? There is some rust on the frame around the battery box, so I'll check everything. Thanks for your help. Brad

 

I use xxxx steel wool to clean corroded terminals then coat with permatex dielectric grease. (autozone).

 

Disconnect battery...May consider cleaning them with electronic contact spray cleaner and wipe with a clean cloth or swab. Check the female plugs in the caddy for corrosion too. Then reassemble with the battery last...
Mice?
Check negative battery cable that goes to frame. Clean contact and tight at both ends.
Check the wire that runs to fuel pump.
Check the little wires to fuel injectors.
Check the wires that go to coil.
I am taking a guess that you have removed the gas tank and reviewed the wires that run under it and have also reviewed how the wires run under the rear frame/fender to the relays...understand major corrosion at the terminal/wire but what about at the ecm connections themselves? is it corrosion or was it a shorting out?

 

a few more things to check:
battery good..voltage 12+, low voltage will not power fuel pump.
green wire from starter to starter relay
two post circuit breaker that is behind battery(just replace it) and check wires to/from
yellow/green to fuel pump and ground for fuel pump
IS THIS A CALIFORNIA BIKE? those have a special pollution door thing that does not like odd starts..
from book:
shares same green that feeds start relay, shares white/black from ecm and a third wire that is black.

 

Thanks for all the insight guys. I'll check all these things. I found an ECM, but I'm going to go over everything I've touched again to make sure the connections are good and that there is no corrosion before I plug the new one in.

 

Just to let everyone know, The bike will now start. Ended up being the ECM. I cleaned all the connections, then plugged the new ECM in, and she fired right up. Thanks to all who gave assistance. I really appreciate it.