Just finished putting my 08 nightster back together. Got it started, and even drove it for about 10 mins after putting in a full tank of fresh gas and an oil change. When I got back to my house, the bike quit while idling. Then it would not restart...

So when I hit the starter, the bike IS CRANKING over. My kill switch is in the right position and my key is also in the right position.

I initially checked for spark by removing the spark plugs, and grounding them to the bike while starting to see if I can visibly see a spark... and I couldnt. BUT I am concerned I was doing it wrong due to the fact that my plug wires are aftermarket and short... so where I am grounding might not be working properly.

Second issue is that when I turn the KEY to Ign, the fuel pump is not coming on either. So I checked power coming out of the System Relay at the Fuel Pump Fuse and I am getting a 1-2 second spike in voltage of 12V... which I believe is correct.

So as of now I believe the fuel pump is bad, and the spark plugs are fine (due to improper spark test). But I can't be 100% sure. The only thing common to the two is the System Relay, wich is sending power to the pump... so I am a bit stumped.

Anyone see this before???

Thanks for you help... I know this is a long read

 

Oh and I have quickly glanced over the bike and no connectors are open. I've checked the ECM for damage, and it looks good. the pins are in good cond.

I did have my fuel tank off, as I put the grinder to make it bare metal. Perhaps I didnt clean the inside well enough before re-installing the fuel pump. If it gets clogged up, does it make sense that it would stop working all together? I assume it would still come on at least, but just not pump any fuel... but I am on here cause I dont know!! hehe.

Thanks again

 

My favorite subject....well let's see where to start!!

You must use a ground to your bike in order to check for spark and best place in on the headbolts(top of them). Alot of people do spark test incorrectly and try using the coated fins for contact point, don't.


Changing relays($8) each is cheap as is cleaning the contacts as they seem to corrode easy. Check fuses too.

Also make sure your battery connections are stable.

My bike wouldn't start due to a bad fuel pressure regulator. When tank was off did you take the pump out at all?? Pump would still prime though if regulator was bad, mine did...hmm. I had same problems almost and thought it was spark(which it wasn't). I changed my whole ignition damn near and the culprit was the $30 fuel pressure regulator on the fuel pump, inside tank. This regulator is actually quite common to go bad from what i found.

Hope this helps

 

All good suggestions by tacokid. It's probably best to use a jumper wire clipped to the sparkplug tang and then clipped to a good ground on the bike to test.

You should see solid voltage, not a spike at the fuse when you turn the key on. If you saw only momentary volts, it's almost for sure the sytem relay is dropping volts across it's contacts inside.

Swap the starter relay and system relay and see if the fuel pump primes and then possibly the engine won't crank because of the bad relay. But sometimes they do come back to like though and work again for awhile.

 

Ok, thanks for the info.

I know I wasnt getting a good ground on the fins and did try using the head bolts, which I checked for continuity to ground before I started with the plugs and nothing... Hmmm.

My next step when I get home is to start again from scratch with a more clear (and less angry!) head..

I did have the fuel pump out for about a month or so while I worked on the tank. There may have been more dust than I thought in the pump which could have clogged it up. But I think it should still cycle regardless. Today I will pull the pump and do some metering. I will also do a more thorough inspection of my plugs and connections everywhere as something may have vibrated off on my first ride.

Suppose I could check the coil too, and try the spark test again. Is the spark really hard to see?

Anyways, thanks again. Any ideas are welcome as riding season is here!

 

Oops, I just saw that reply about swapping the solenoids after I wrote my last msg. I wasnt sure if the System Relay was supposed to drop the voltage. I guess I thought that because the pump only came on momentarily I supposed that the ECM was cutting voltage after a second or so. I'll definately swap those bad boys.

One more question.. when you metioned connecting the spark plug 'tang' to a good ground, would wrapping a wire around the threads of the plug and jumping it to a ground work as well??

 

Don't do anything before you swap those relays, or buy a new one to use for swapping. But if you look at the wire diagram, the power from the system relay goes out to feed the fuel pump, the ignition coil and the fuel injectors. It will always provide 12 volts continuously when the key is on.

 

Yeah, that should work too.

 

Listen up when blackcherry_low talks. He gave me alot of VERY good ideas. You learn everything from others, or others mistakes!!

 

Man, I swapped the relays and BAM the fuel pump fired right up as soon as I turned the key.

When I looked at the diagram I saw that the relay provides power to the fuel pump, coil and injectors continuously. I assumed that the ECM was doing its magic to turn it off after a bit. I also assumed that to be correct because you only hear the fuel pump wind up for that short amount of time when you turn the key on. Assuming has gotten me in trouble in the past, and I hope to learn from my mistake!

Thank you very much man. I just got back from HD with the 20$ fix in hand. I'm gonna go put the new one in and button everything up. I'll conclude the thread once I finish up.

Thanks again!