EFI gurus...help.

okay, my 81 kawi is EFI. Since it is a pretty set system and i wanted to run a straight pipe, i installed an AFPR. After i got it installed the bike fired right up. BUT...the injectors are noisy as hell now, like you can hear it quite well...normal? i don't have the pressure up far, but the lowest setting is more than the stock one does....Or did i hook the lines up wrong????

this is the one i bought....i was told fuel in goes to top nozzle (across from barbed end with the nut), and return goes off of side nozzle, and vaccuum is off of the barbed end correct? or do i have it backwards?



Post edited by: tnutz, at: 2007/04/12 20:56

Okay, got it working, The noise was a missing vaccuum cap...runs wicked and plugs look good after rippin on the highway...Now the shitty thing...Tank fell off while i was working on it, thought i put it back on properly...apparantly not. I always said if i binned it i would repaint, so here is my oppertunity i guess.

Congrats on getting it running better! I have a stock 82 GPz 1100 w FI. What have you done to make yours run better? What is an AFPR? This enquiring mind wants to know!! lol

adjustable fuel pressure regulator IIRC
next step is connecting a power commander(if possible) or megasquirt
lorcan has a section on his site about connecting a power commander to a gpz

An adjustable fuel pressure regulator can help iron out weak spots caused by fitting less restrictive air filters and exhausts etc. Stock fuel pressure is 37psi, bumping it up to 40-42psi can help with the stumbles, and so can tweaking the throttle position sensor a little. On USA bikes the TPS has a cover with 4 little plugs that can be removed with a small screwdriver, the TPS itself has two screws (marked with yellow paint) which you can slacken off and rotate the TPS left or right (left for weaker, right for richer). On european bikes the cover is located with 4 crosshead screws. This lets the ECU think the throttles are less/more open than they really are and adjusts the fuelling accordingly. Generally you should adjust to the highest idle, then reset the idle speed with the idle screw. It's very sensitive though, and you might want to mark the original position with a scribe before you start. You should also balance the throttle bodies before adjusting the TPS.

Obviously both adjusting the TPS and raising the fuel pressure can have quite wide ranging effects. To map the ECU accurately at different load points requires going the powercommander route, which requires a swap to modern "high impedance" injectors, or a complete change to a fully programmable ECU, but for minor modifications adjusting the TPS and fuel pressure can yield quite satisfactory results.