klwgsxr1000

Can a 929 or 954 fuel pressure regulator fit on a F4i????

SLOPDIDDY

why ?a bigger motor requires more fuel so a f4i would require less. i would think... most fuel injected engines operate around 35-55psi fuel pressure....roughly. the injectors and map sensor ultimately determine fuel delivery amount so if the holes line up id try it.the regulator is controlled by vacuum i believe on these so no matter what if it fits it should work.

klwgsxr1000

its bolts up perfect, but just trying to figure out is it the problem on my bike(f4i). bike idles fine at 1000 to 1500 rpm. but when i turn the second idle cable(not the stock) to 3500 its surges back and forth.

~ZJ~

make sure something isnt loose on the throttle body assembly. but the fuel pressure regulator off a 929 shouldnt make a noticable difference. my fpr was leaking fuel to the vacuum side and to make sure that was my only problem i stuck a civic fpr on it and it ran, not well but it ran lol. it bolted right up but it didnt run the right pressure, i dont know if it was too high or too low. but it doesnt sound like your fpr is the problem, sounds more like the pins that let air bypass the butterflies for idle are loose for some reason. let us know what you find

klwgsxr1000

ok...cool...i dont think its the FPR either, because i was troubleshooting the f4i and found that when turn the second idle cable to 3500 rpm, i can grab the throttle and turn it the opposite way(not giving it gas) and the idle goes down to like 2500 rpm. once i let let go(like im give it gas but im not) the rpm races back to 3500 and starts surging again....WTF?????

~ZJ~

hmm how do you have the second idle screw set up? sounds like its moving the butterflies to change idle. i dont know how thats usually done, i havent done it to mine. but if it is, then it sounds to me like its a throttle position sensor, and check if the cable is tight at the throttle bodies when you have the idle at 3500. the TP sensor could def make it surge.

klwgsxr1000

i have the second idle cable going to the throttle bodies.Take out the set screw and screw in idle cable. The stock idle does it by air and fuel...the second idle cable is straight to the throttle bodies opening the butterfly...if i exlpain that right.....

*Tanus*

thats fucked up, haha you must have the 2nd cable on the wrong spot