Anyone know how to test a fuel pump?

22opel · 05-31-2009, 9:29 PM

I have an 02 f4i and it has the relay (closest to the taillights) clicking when i turn the key on. I could no longer hear the fuel pump priming and the bike won't start, so i have now taken my tank off and have pulled the fuel pump out... does anyone know how to tell if the fuel pump is bad? If it isn't, does anyone else have any suggestions as to what could make the bike not run?

P.S. I have a dead battery. It is a new battery as of last summer. i was wondering if the fuel pump being bad could be sucking all of the power from the battery because it seems to not wanna charge.

Jetpilot07 · 06-01-2009, 9:20 AM

a bad battery will cause this sometimes...if you left the battery in the bike all winter, most likely it died because of the cold, replace the battery and the problem will solve itself......

you need so many volts to start the bike and run the computer at the same time.

also, take a peek at the fuses.......

22opel · 06-01-2009, 2:55 PM

so i have already checked all of the fuses and they are all good. and i have connected my bike to an outlet power source in the wall, and still no juice.

i can hear and feel the relay on the back right of the bike clicking like mad but i do not hear the fuel pump at all

stiffer56 · 06-01-2009, 5:14 PM

If the relay you hear clicking is the fuel pump relay that is most likely the problem. I am almost finished with school to be an ASE certified auto mechanic. I would check the relay first. Low battery voltage will have nothing to do with the relay clicking. It only takes 200mA or lass to operate a relay. That is what they are used for. They allow a low amperage power input to control a high amperage circuit. Also when you turn the key on and hear that initial whine...that is the fuel pump priming the system... so even if there was a voltage issue the prime would be enough to fire the bike it just wouldn,t keep it running. However the stator should begin to charge and make up for a weak battery. You can test the fuel pump itself by jumping 12v power and ground to the pump... it should turn on. I would not recommend this unless you are completely positive of which wires are which. If you can post a pic of the relay I can probably tell you how to jump the relay to determine if it is bad. A pic of the terminals with it removed and a pic of the side if there is a schematic printed on it. If you are having battery issues also there is something probably sticking on when the key is off. Relays can hang in the on position and run the battery dead. Hope I can help you out.

22opel · 06-01-2009, 6:49 PM

I do not hear "that initial whine" when i turn the key on, that is how i know that the fuel pump is not priming. i already have the fuel pump out of the tank and i am trying to find out if it is any good. i don't know wich wires i should run power or ground to so i don't know how to test if the pump is working or not. Here are some pics... the first ones are of the relay that is clicking, the others are of the fuel pump and wires.

thanks for any help.

22opel · 06-02-2009, 3:38 AM

Alright, an update for you. i took my fuel pump out and connected it to a steady 12v current and it turned on. so the fuel pump is fine.

I also tested where the fuel pump plugs into the wiring harness... no power.
so somewhere between the battery and the the wiring harness power is getting cut off.

When i turn the key on with the pump plugged in, the relay and pump click like mad forever... when i turn the key on with the pump disconnected, the relay will click once when the FI light comes on then once when the FI light turns off then won't click anymore.

So could i have a bad ECU? A wire short? Bad Relay?
Any Ideas?

22opel · 06-02-2009, 10:18 PM

An Update...

I pulled the relay and jumped the brown and black/white wires together.
the fuel pump then comes online with the key on.

so does that mean i have a bad relay? i tried switching the 2 relays (at the back of the bike above the right passengers foot peg) and i get the same result- clicking relay and fuel pump.

also when i jumped the 2 wires and got the fuel pump to turn on, the bike still won't start. it cranks over just fine but will not start.

I can't find any problems with the wires or grounds.

any other ideas?
http://cbrforum.com/forum/images/kir...c/progress.gif http://cbrforum.com/forum/images/kir...ttons/edit.gif

22opel · 06-04-2009, 3:07 AM

alright i am baffled. i cannot find anything wrong with the kill switch. i pulled the spark plugs and tested them and they all worked fine. i put the plugs back in and put some fuel in each of the cyliders and then i turned it over... nothing. i even tried starting fluid and still nothing. i don't get it, i have spark, and i gave it fuel why on earth will it not start?

could the ecu be pulling timing so much that it won't even start? i can't imagine having no compression since i rode it last month and just let it sit and now it won't start. i would check the compression but i don't have a tester that will fit into the small spark plug holes.

anyone have any other options?

vblood · 08-26-2009, 2:30 PM

Hi, i have the same problem did u sorted out, what was it?thanks

R Dub · 08-26-2009, 3:57 PM

It seems that the fuel pump not priming is a very common issue on these bikes. I have had this problem on my 01 F4i. Unfortunately there is no simple answer. I have seen a lot of people think its the relay, go out buy a new one and then that does not fix it. If the relay clicks that means that its good. It seems there is an electrical issue somewhere and we all know those are a pain to locate. The problem with mine was ground wire(green) for the headlight sub harness had a bad connection which probably came from the previous owner hacking into it and not routing the wiring harness properly. I think a good way to tell if you have the same problem is see what your cluster is doing. If the top of your cluster is all light up besides the FI light the you probably do. You should be able to take off your left fairing and get to the sub harness. I would disconnect it, make sure it is not corroded or burnt, clean up the contacts (even on the side that the wires go into cause that's where my issue was) put A LOT of dielectric grease on it and see if that does the trick. Also these bikes need a full battery to start and run. Even if it turns over good, there might not be enough juice to start it. Make sure your battery has a full charge.