GSX-R1000 Fuel Questions

[komelika]

I finally got my engine running after some help on Gixxer.com figuring out a misleading Suzuki diagram. 

I have a couple of questions. It will only cold start when I prime the carbs. Otherwise it barely coughs about every third or fourth try after the fuel pump primes. I did unplug my fuel line and it pumps, but it doesn't seem like much pressure. I can pinch the fuel line pretty lightly and stop the pump. Suzuki says it needs 40 PSI. Sounds like a bad fuel pump, right? When I prime the carbs it will run and keep running, but when I rev it quickly it cuts out. It will rev slowly without cutting out, but if I blip the throttle it cuts out.

I may also have a bad IAP sensor. I have one being shipped, but the one I have kills the motor when the vacuum line is connected. So as of now the vacuum line is at atmosphere. Hopefully the IAP sensor solves everything and I can avoid another fuel pump.

Any thoughts? Thanks

[dsrace]

40 psi for carbs?

[komelika]

40PSI to fire injectors. I kind of doubt its the fuel pump. Probably more of an IAP sensor issue. I found the test procedure in the service manual (keep forgetting I downloaded that), so I'll check it when I get time. Hopefully later today.

[Lance-W]

Kinda of a dumb question but the filter on the pump and the actual inlet for the pump are clear?

[komelika]

Good question. I didn't realize the pump was so serviceable when I installed it so I didn't disassemble and clean the filter. That will be the next step if the IAP sensor doesn't do the trick. Probably needs to be done regardless. I'm learning a ton about this engine and everything involved... so that's a good thing! LOL

[fabr]

+1!

[MC]

In general if the motor has been sitting awhile, like when your building a car, you really should send the injectors out and have them cleaned. I see this all the time, dirty injectors and bad grounds. I suggest to my customers to send the injectors out for cleaning before the start of each race season and clean all grounds.

The stock fuel pressure should be around 43 LBS, I would suggest bumping that to 47-48 if your not using something like a power commander.

[Lance-W]

If the fuel line when the pump is on is soft then I wouldn't think it was dirty injectors?  40 psi is gonna be hard to crush the line with just your fingers I would think.

[fabr]

In general if the motor has been sitting awhile, like when your building a car, you really should send the injectors out and have them cleaned. I see this all the time, dirty injectors and bad grounds. I suggest to my customers to send the injectors out for cleaning before the start of each race season and clean all grounds.

The stock fuel pressure should be around 43 LBS, I would suggest bumping that to 47-48 if your not using something like a power commander.

Good advice for sure. My first busa ran like crap for quite a long while. I think it finally dissolved the majority of crud in about 60 gallons. Ran great then. 

[komelika]

That might be a blessing. It'll give me time to calibrate the steering wheel operator before it reaches warp speed! 

[fabr]

That steering wheel nut should be tightly torqued...........................................

[komelika]

That steering wheel nut should be tightly torqued...........................................

Yup!