i m curious about the 91 hatch Si's stock fuel pump, how does it compare to say a fuel pump from a teg? would it be adaquate(sp.?) for 11.1.1 compression? what about the whole fuel system? i just got done w/ my little build up, Ls w/ Pr3 pistons ect. and i started up the motor and i hear a noise that sounds like pebbles are being droped into my cylanders. so that would be detionation. and my entire fuel system is stock, so would it be adaquate? im about to get a S-afc or help combat this. i just wanna hear some opionions. thanks

 

yes that sounds like your engine is pinging. and as far as the Si fuel system. Its great. buy only for what it was intended for. SOHC. Personally i would check your fuel pressure and O2 sensors first. If you havent already done so, get a fuel pressure gauge and make sure your O2 sensors are running right. ( little known fact. if you run your car too rich even once. your O2 sensors are fouled and must be replaced ) the stock fuel system should be able to do a fair job of running your set up. if your pinging i would say there is a problem with what you have. not with what you havent upgraded yet. I have seen 12.2:1 type r engines run very well with a CX fuel punp and B16a injectors. Also remember that compression doesnt mean fuel is needed. remember more air needs more fuel. if your not adding air flow dont add more fuel. hope this helps and IM me if needed.

 

I'll bet your valves are hitting your pistons... not detonation. The LS and the PR3 pistons DO NOT have the same style fly cut for the valves. Period.

I put LS pistons in my B16a to lower the compression for the turbo and the valves had been beating on the pistons VERY badly. I'd set the motor at TDC, pull a plug and see if you can see andy shiny where this has been happening.

See the little crescents on the top of the valve relief... that's where the valves were hitting.

 

well when i had my 404's in i was running very rich at idle, so would that might cause my o2 to go bad? as for the pr3 pistons in the ls, i asked a bunch of people who was running ls w/ b16 pistons and they said the have no clearance problems, but the problem would be when you drop ls pistons into a b16 becuase the b16 valves relifs are bigger then the ls's. duno if im making any sence. you think i should try getting a gallon of 105 gas and pour some in just see if it would stop pinging? would i have to wait till it mixes w/ the gas thats already in my tank? i have a full tank of 92, how long would ti take to mix? thanks


[Modified by bobo, 9:41 PM 1/26/2002]

 

Is there any difference between a 88-91 si fuel pump and a 88-91 std. fuel pump?

 

i dont think there is a difference. But to know for sure call you local dealership and compare part numbers. if they are different then its probably a sure bet that the SI is bigger. but if you still need a bigger pump. try an type R.