AEM Intank pump and s2000's

[heavyd]

I put an AEM Intank fuelpump with s2000 injectors on my Gen I 1397 Hayabusa.  The bike won't run right and the data logger sometimes show  18 to 1 and in other areas 11.5 to 1.  Any thoughts?  I am running 93 pump fuel.  It spits and bucks and acts like I am pulling out in 3rd gear.

Thanks

[blt1]

Sounds like you need a proper tune, anytime after making changes as you have made the new combination will need to be tuned to optimize the combination.

[heavyd]

I have been working on the tune with my data logger.  The problem is that it goes really lean to really rich all over the rpm's.  Sportbikerider said in another post that the gas cap could not be venting properly.  I have an aftermarket gas cap on it so I am going to remove it and see what happens.

Another thing, I crushed the regulator and it is at 58PSI.  I don't know if that has anything to do with it.

Thanks for the help.

[RansomT]

how are you tuning it?

[heavyd]

Wideband Commander and ECU editor.

[Oz Booster]

58 psi on s 2000 and mild mods , your probably rich misfire giving a lean reading

[sportbikeryder]

58 psi on s 2000 and mild mods , your probably rich misfire giving a lean reading

Yup.

I f it is just a normally aspirated bike, I think I'd pull the s2000's and go back to stock, with the 58psi fuel pressure.

While using an on board logger can help with fine tuning driveability, trying to do a full tune is not a trivial task, especially if you don't really understand the tuning or have experience with the combo.

[RansomT]

58 psi on s 2000 and mild mods , your probably rich misfire giving a lean reading

Agree'd .... first thing I would do is lower the fuel pressure to 40 psi.   At 58psi, your 35lb injectors are delivering fuel at a rate of 40.5 lbs.  That's enough to easily support 300 wHP.

[heavyd]

Thanks for all your help.  Before I put the AEM pump in I had it running pretty good using the wideband with the stock fuel pump, S-2000's and 58PSI.  I want to start adding a dry shot of NOS so I put the bigger pump in and now I am having problems.  I have a stock regulator that I am going to put in to bring my pressure down and go from there.

Thanks again.

[Rocketgeezer]

Thanks for all your help.  Before I put the AEM pump in I had it running pretty good using the wideband with the stock fuel pump, S-2000's and 58PSI.  I want to start adding a dry shot of NOS so I put the bigger pump in and now I am having problems.  I have a stock regulator that I am going to put in to bring my pressure down and go from there.

Thanks again.

I did about the same thing except right about the time I put in the new pump, I used the big AEM looks like a B-44, did not change nothing else in the tune up, but between replacing the pump, rail, lines, new PC-V, ign module, and autotune, I really had a time getting running right, I used the same basic map, but the biggest problem turned out to be that big pump with that much more volume, was just a lot more fuel than the motor needed, I know it really needed some dyno time, but around here we ether have Harley guys or couple of dudes I would not let near my lawnmower, a out of town trip to a pro was not a option, it took me awhile but its flyin now

[sportbikeryder]

My guess us that you have erratic fuel pressure. The stock intank regulator can only bypass so much fuel. The aem pump is higher flowing than stock, especially at higher pressures. You are most likely at higher fuel pressure sometimes if the little stock regulator cant bypass enough fuel.

Either way if you are trying to do all of these changes without real tuning, you are really leaving alot on th take in plwer, driveability, and general system robustness. Take it to someone who can tune it for you so you can actually enjoy the bike.

[heavyd]

I switched out a lot of things trying to get it to run right and the only way I can get it to run right is with the stock fuel pump and regulator.  I tuned it with the Wideband in the IAP map and it is running great.  I will take it to the track in the next couple of days and tune it in the higher RPM's.

Do you think I would have the same problems with a Bosch in tank pump?  I want to start running e-85 and a dry shot but there is no way that the stock fuel system will handle it.

Thanks