Honda 929 No Power to Fuel Pump

crxtacy · 09-18-2007, 3:38 AM

I AM SORRY THIS IS LONG, BUT I AM TRYING TO GIVE YOU ALL THE INFORMATION SO THAT YOU CAN HELP ME BEST DIAGNOS THIS PROBLEM

I recently purchased my first Honda. This is a stunt bike. I have had it for a couple months now with no problems, until i put the dirt bike headlight on. the front wire harness was on the bike previous to me putting on the headlight. I wirred up the new headlights and was tucking everything away, started it up and it ran just fine. decided to raise the headlights up, and went to start back up for a test ride. no start. the fuel pump was not kicking on. i started at the FI fuse, it was good. moved on to the engine stop relay, it was getting 12v in and out, was also clicking when ignition was turned on. the bank angle sensor has been modified by me. soldered and heat shrinked, this is good. engine stop switch has been checked and is good. i thought i had found my problem when i got to the fuel cut relay. on the electromagnetic side it is getting 12v going in and coming out. but on the actual switch side has the 12v going in and the switch is never clicking to there is no 12v coming out to go to the fuel pump. i have working with relays before and i have never seen this.

i have been doing some reading on this site and found out this bike has some sort of an anti-theft diode in the ignition switch. if the diode is bad the fuel pump will not kick on. 3 of the 4 wires on the ignition switch are supposed to read 12v and the other pink wire is supposed to read 9v. All four of my wires coming from my ignition switch read 12v.
here is the link of the thread i found about this.
http://www.fireblades.org/forums/hon...e-no-more.html

also when i put on the new dirt bike headlight i had cut some of the unnecessary connectors off of the front wire harness.

before reading about the anti-theft diode in the ignition switch i had switched out the relay for the fuel cut off, and no change. i hard wired the fuel cut off relay so that the fuel pump with kick on, this worked. the fuel pump kicked on, and stayed on continuously(i didn't know if it was normal for it to stay on all the time because my 02 GSX-R's fuel pump kicks off after a few seconds). tried to start and all it did is crank.

have not checked spark, and have replaced battery.

any help would be greatly appreciated!

929man · 09-24-2007, 9:27 PM

Well the Diode is a Ziener diode.. and i am trying to find the same thing if the ziener is not good.. you are definately going to have this problem.. a quick fix would be to get another ignition from the 4 pin to the ignition and replace it.. this might help.. as soon as i find out what the diode value is i will le tyou know..

mguzzipilot · 09-26-2007, 12:53 PM

I'm having a very similar problem.

Track bike that ran fine. I cut off some wires leading to the headlight and turn signals and it still ran fine. I took the tank off to paint it, put it back on, and not there is no juice to the fuel pump and the engine stop relay isn't clicking.

I tested every fuse and every relay I can find and everythink is A-OK.

I never heard of this diode in the ignition - is there a way to bypass it? Being that it is a track bike, I don't care about theft prevention...

I'll measure voltages at the ignition wires and report back...

929man · 09-27-2007, 2:14 PM

i just called honda and they have no clue that a diode was in there in the first place.. theyjust wanted me to buy the whole unit again... anyways... from what i saw on the ignition it looks like it might be one of a few diodes.. you have to make sure that they are Zener and have to try which value will fit better.. they range from 1watt 1volt to 1watt 15 volts.. your best bet would be to try from 5 to 11 volts.. since the battery is about 12 so that would be my educated guess.. i will try them this weekend.. and let you guys know

no there is no way of bypassing it.. as it has been programed for a small increase in voltage the current increases considerablly
just look up Zener applications..

solorsix · 10-11-2007, 4:11 PM

sounds like a 9V zener there. zener diode acts like a regulator (poor mans).

929man · 10-15-2007, 11:31 AM

no its a 3.9 volt zener... dont ask me how i found that out.. now i have to return a whole bunch of them... any 3.9 v would do the trick... oh and it has to be 1/2 watt.. trust em it works like a charm... an it only costs about 20 to 30 cents...lol