Motorcycle Racing Forum

Racing Discussion => Racing Discussion => Topic started by: Steviebee on May 05, 2003, 07:45:59 PM

Title: Help me...  Please...
Post by: Steviebee on May 05, 2003, 07:45:59 PM
OK,  so i cartwheeled my bike at BFR 2 weekends ago.  Now im almost got it back together and got a problem.

A.  Dam thing wont start.
B.  The fuel pump doesnt shut off after a few seconds (like it used to).
C.  Dam thing dont start.

I destroyed the subframe and everything in it when i crashed. I put in a new battery reconnected everything, check the tipover sensor, even pulled the fuel pump and looked at it.

It is pumping fuel, (now im covered in it, good thing i quit smoking!).  But why doesnt it shut off ???

I also got another computer (off Ebay) is there a way to check to see if the computer is ok?

Grrr  Im going out of town all day tomorow so i can t work on it tomorow night.  And Wed i gott bring it to get the frame welded back together.

So lay on the sugestions !!
Title: Re: Help me...  Please...
Post by: EX#996 on May 05, 2003, 08:07:17 PM
Steve.....

What year and type of bike?  This is needed information to offer suggestions.

Dawn  :)
Title: Re: Help me...  Please...
Post by: GSXR RACER MIKE on May 05, 2003, 08:27:27 PM
QuoteSteve.....

What year and type of bike?  This is needed information to offer suggestions.

Dawn  :)

     His signature says it's an '00 GSXR 750.
Title: Re: Help me...  Please...
Post by: Steviebee on May 05, 2003, 08:39:12 PM
ooops..  and yea..

This is a bummer cause im supposed to be in the VRS school on Thursday, Practice on friday and racing sat and sun, this weekend.

My computer was a bit banged up, so i got one off ebay.  Now im wondering if the guy sold me a crapped out computer ?

I might have succumb (spelling, hey I r the engineer) and bring it to the suz dealer. :(
Title: Re: Help me...  Please...
Post by: GSXR RACER MIKE on May 05, 2003, 08:47:47 PM
     I really don't know what to tell ya about your problem, but I think a simple check as far as the computer goes would be to get a computer off someone elses bike (that works) and see if it works on your bike. I know there were some changes made on the GSXR 750 since '00, so you might want to see if the dealer can tell ya if any '00 or newer computer will work (or if it has to be an '00 model computer?). I don't know what was changed on them, but it may have been the computer? Was the replacement computer the same model year?
Title: Re: Help me...  Please...
Post by: Steviebee on May 05, 2003, 10:22:57 PM
it was supposed to be an 00 puter.

Title: Re: Help me...  Please...
Post by: DRU2 on May 05, 2003, 11:08:37 PM
DID YOU TRY THE OLD COMPUTER? JUST A THOUGHT
Title: Re: Help me...  Please...
Post by: shook1 on May 06, 2003, 12:46:00 AM
Ok, I don't own a Gixxer, but, i'll give it a shot.

What normally tells the fuel pump to shut off?

Logic says that there has to be feedback (probably from the throttle bodies) to the computer that says, "there is enough gas for now, thank you, now shut off the fuel pump!"

I would check the sensors around the throttle bodies to make sure you don't have a short or that they are connected properly.  My R6 has a sensor on the carbs that checks the height of the float in the carbs.  When the float level is good, the fuel pump shuts off.  I would guess you have a similar arrangement.  Even if it is fuel injected, some type of sensor has to tell the computer when to shut off the fuel pump.  Good luck :)

And damn I must have crashed hard, cuz I forgot I do own a Gixxer 1000 that I ride on the street.  :-[
Title: Re: Help me...  Please...
Post by: shook1 on May 09, 2003, 09:08:09 AM
So what happened StevieBee?

Now that I've remembered that I have a Suzuki, I would like to know what was causing your problems so I can store it away for future reference.
Title: Re: Help me...  Please...
Post by: dwilson on May 09, 2003, 09:23:35 AM
If it's pumping fuel but not starting, where's the fuel going?  After you find that out the rest of the troubleshooting may be easy.  Wouldn't it be nice if it were just a broken hose.

The fuel pump on my FZR will just keep pumping for about 10 seconds solid if the fuel valve is turned off, I learned that the hard way  ;D
Title: Re: Help me...  Please...
Post by: Litespeed on May 09, 2003, 11:16:36 AM
Typically the pump will shut off when it hits a certain pressure.  If you have it out in the open it's likely it won't shut off.  I'm not sure if there is a place for it or not, but try to get a fuel pressure gauge on the systema nd see if it pumping fuel at the required pressure.  If it is coming up to around 40 psi (just a guess, that's what most cars operate at) then you can assume it's good.  Once you determine that you have fuel pressure you will have to figure out how to tell if the injectors are working like they are supposed to.
Title: Re: Help me...  Please...
Post by: Steviebee on May 09, 2003, 05:38:46 PM
well i was going to be "lazy" and bring the bike to the dealer today to get it fixed.  I figure they be able to figure it out in no time flat.

Guess what they told me, Make and apointment, and the first one available is June 19th.    ??  what a way to do business.


Honestly i think that the computer is fried, and the one i got off ebay is junk !!

I cant get the computer into its diagnostic mode.

Yes, i tried the old computer.
I dont believe the pump shut soff at a certain pressure, it has a bypass valve inside the tank that opens to relieve pressure.
I "believe" the computer tells the pump to prime itself for several seconds and shut off if the moter is not on.  

I dont know anyone with a 2k gixer to borrow thier computer to try thiers. :(

Thanks for the sugestions,  Im going to check if the plugs are sparking.  After diner and a cold beer.

Atleast my crash saved me 800$ in pre-entry fees for RA and BFR, but id rather be racing.  
Title: Re: Help me...  Please...
Post by: Woofentino Pugrossi on May 09, 2003, 07:50:32 PM
Steve, generally the computer controls the pump (btw I'm going off car FI here), and usually only runs the pump to prime the system. The bypass in the tank is just to bleed off excess pressure and when you shut down, the whole system depressurizes.

Before you throw that computer(s) away, check EVERY wire and sensor. Its quite possible that a wire was ripped off that the bike needs and with the amount of damage you had, that wouldnt surprise me.

BTW you are lucky a shop would be willing to look at your bike. The one I USED to go to wont touch anything that is remotely looking like a racebike.
Title: Re: Help me...  Please...
Post by: Steviebee on May 09, 2003, 10:46:13 PM
they didnt even ask about being a race bike.


I did trace all the wire to make sure there hooked up (theres only a few)  and checked the fuses too.  Cause the manual say that the speedo will show a "chec" code when the signal is interupted from the ecm.  ?? no luck thou.  

Title: Re: Help me...  Please...
Post by: Steviebee on May 10, 2003, 11:07:35 AM
now im bummed..

Just got back from teh Suz dealer.  Guess how much they want for a computer.....  840$

:(

WTF !!

Anyone know where i can get a 00 gsxr 750 computer ??   err cheaper than 800$

 >:( :'( >:( :'(
Title: Re: Help me...  Please...
Post by: Woofentino Pugrossi on May 10, 2003, 05:08:53 PM
Try ebay or some salvage yards ( www.madmanbiker.com for example)