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-   -   2002 F4i no spark no fuel pump! (https://cbrforum.com/forum/f4i-main-forum-11/2002-f4i-no-spark-no-fuel-pump-136231/)

squidhead 04-01-2012 01:16 PM

2002 F4i no spark no fuel pump!
 
we have done everything possible and it will not start. first we changed the fuel pump it was bad. then we found out it would not prime because relay was not sending voltage to it. bypassed relay and bike started. so then we started to trouble shoot the problem checking every plug and wire in the whole system. ecu threw all kinds of codes so we reset it and still nothing plus now we have no spark and no fuel pump. yes we checked the bas, kill switch, zener diode in the ignition, plus all other possibilities. anybody have any ideas we might have missed? only thing we can figure is the ecu was going bad meaning the fuel pump issue and now it is done because we have no spark to.

jworkman78 04-01-2012 03:56 PM

I have the same thing happening to my bike. No fuel pump and no spark. Fuel pump works when I wire it directly to a power source. I've bypassed the bad and unhooked and cleaned all of the connectors. Still nothing!! It's driving me crazy. I hope someone can help us and I really hope it's not the ecu

mnguyen84 04-01-2012 11:11 PM

does the starter turn? if you checked everything then try swapping the ecu.

squidhead 04-02-2012 03:47 AM

starter works as does everything else. getting ecu this week will let you know. that is the only thing left. still can not figure out how a bike can sit all winter being started every week then fuel pump goes, thats possible, but the no priming ofter being changed like i said in previous post, then after jumping relay bike starts then decides not to start after 4 days???????? thats when the spark was gone. any body have other ideas,HELP

squidhead 04-06-2012 08:10 AM

new ecu should be here today? going to swap it out and see if it is my problem. i notice lots of posts with similar problems, before i swap out ecu does anybody have any other ideas?? if it is another problem i dont want to cook this ecu.

cobra1000rr 04-06-2012 09:26 AM

I would say ECU also, it controls everything so that is were i would start, If you knew the wire leads from ECU to relay you could check for voltage and see if it gives a signal or power the relay.

squidhead 04-06-2012 01:30 PM

thats the crazy thing. check ecu for grounds, all good. traced pink wire zener diode 8.5 v @ecu. fuel problem is fuel pump relay is getting 12v from ecu on b/w wire where it should not. swapped relays and same thing.

IDoDirt 04-06-2012 02:11 PM


Originally Posted by squidhead (Post 1147266)
thats the crazy thing. check ecu for grounds, all good. traced pink wire zener diode 8.5 v @ecu. fuel problem is fuel pump relay is getting 12v from ecu on b/w wire where it should not. swapped relays and same thing.

Why do you say that the ECU is getting 12v from the Fuel Pump Relay on the Black/White wire ? If you're referring to the Fuel Cut Relay as it's referred to in the wiring diagram, it has 2 Black/White wires going to it (the relay).

squidhead 04-06-2012 06:45 PM

im sorry, the fuel cut relay is getting 12v from the starter relay. not the ecu. problem is it does not send it to the fuel pump on the brown from the relay. put the other ecu in today and same thing no pump and no spark!!!! if i power the brown at the relay with powerprobe pump will run. that means brown wire is not broken. tested both relays and they are working properly. even switched and tested it with headlight relay and same thing. i am missing something! studied wiring diagram and i am stumped. whatever it is the bike is in tip over mode??? i guess. bas is also fine tested and jumped. anybody else HELP please. what else in the fi system would do it. zener diode is also fine.

IDoDirt 04-06-2012 09:44 PM


Originally Posted by squidhead
im sorry, the fuel cut relay is getting 12v from the starter relay. not the ecu.

I'm sorry if I seem like I'm asking you to repeat things, but since we're not standing in the same room, you can't just point at something and have me see what you're pointing at.

That being said, what are you calling the Starter Relay? Are you referring to the Engine Stop Relay, or the Starter Relay Switch


if i power the brown at the relay with powerprobe pump will run.
Explain what you mean by this statement. If you're saying that if you provide 12 to the Brown wire from the battery using your test probe, then you're just showing that if the Fuel Pump is told to turn on, it will.

The ECU controls the Fuel Cut Relay by supplying a path to ground on the Brown/Black wire. That is the controling side of the Fuel Cut Relay. If that relay is not told to come on, then power will not flow from the Black wires, through the Fuel Cut Relay contacts and come out on the Brown wire to be supplied to the fuel pump.

Now, the Fuel Cut Relay gets its power from the Engine Stop Relay. Both relays are side by side. We need to be sure that you're identifying them correctly. The Engine Stop Relay has a Black wire going to it, and a Black/White wire. The Fuel Cut Relay has 2 Black/White wires going to it. It also has the Brown wire that you've spoke of before.

Do you have 12v present on the 2 Black/White wires of the Fuel Cut Relay ?


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