Civic Si not running right

i have a civic si with a jackson racing supercharger, NOS, and lots of other things, and ever since i had the car professionally tuned and had a hondata s200 installed, the car runs like crap. it doesnt pull like it used too. also after the spark plugs have been in the car for a while, it starts sputtering at about 5500-8000 where i shift. the sputtering wont let me accelerate anymore in the range. wen i change them, i can get about nine runs on the 1/8 mile before it starts sputtering again. the car ran a 9.3 on a 1/8 mile and ever since i have had it tuned, the best i have gotten out of it is a 9.8. i have had this probly for close to a year and any help will be greatly appreciated.

Sound's like tuning gone bad. Get someone else to take a look at it.

9.3's with a supercharger and nitrous? that's kind of weak man...

What year si?

its a 2000 si. its only running 8 pounds of boost with a 60 shot of nitrous. does the tuning also affect the problem with the spark plugs?

i would take the car back to that tuner and tell him i paid you good money and my car runs like shit.

did you get the right temp spark plugs for you setup?

well after i got the car back from the tuners, i emailed and called them a million times and they never returned any email or call. so i found the next closest place to me but they dont do dyno testing. they are the ones who told me wut spark plugs to get and wut to gap it to. im just really pissed and want to fix this problem. is it tuning or something else?

do you have an aftermarket Fuel Pump?
What fuel mods do ya got??

440 Rc engineering injectors, str fuel rail, i had a aftermarket fuel pump but the tuners thought it was "better" if i took it out. i still have the aftermarket one.

you deff need an aftermarket fuel pump in there it's probably not supplying enough fuel to the injectors for the nitrous and supercharger to work correctly.

i will change that out asap but wut about the problem with the spark plugs?

i was looking at the car today and i realized i made a big mistake on one of my post. i DO have a aftermarket fuel pump (Jackson Racing) but i dont have a aftermarket fuel pressure regulator. i do have the Jackson Racing fuel pressure regulator in a box thou. sry bout that. thanks for everyones replies so far

yep better finish the fuel system and make it correct before anyone is blamed. Ya with that setup, you better have a fuel pump!

i dont mean to be annoying but wut is causing the problem with the spark plugs becuz its getting annoying that everytime i go to the drag that i have to buy new spark plugs

how do the plugs look when you take them out ?

they look normal i compare them to the hanes manuel i have and nothing is wrong with them. im using NGK R spark plugs if that helps any.

have you tried just reseating the same plugs? just take the same ones out and put them back. spark plugs are pretty simple, so if they look fine, i cant see why they would be failing.

does this happen on the street as well, or only when you are at the track? are you doing all 9 runs in the same night, or are they spread out?

it happens on the street wen i go full throttle and on the track. sometiems i do 9 runs all in one day and sometimes i do it over a period of time.

if the problem really is the plugs, it means you are somehow fouling the plugs. how you are doing it comes from what the plug looks like. try this site: http://www.gamespot.com/live/streamer_new2.html?title=Nintendo+DS+Demonstration&path=dsdemo-e32004.asx&pid=920757&ppath=ds/puzzle/wariowareincds&ksubmoid=0d8417db-3d0f-a13c-74fb-ae61665cfb17&urdate=1104480000 . it will tell you how to read the plugs, along with give some ideas on how to fix it.

oops. wrong site. try this one: http://www.autosite.com/garage/encyclop/ency04e.asp

im starting to believe the car is running rich. that will cause the plugs to foul and cause all the problems im having. the fuel pressure is around 60 or 65 and that seems high. i have a hondata installed with the stock fuel pressure regulator so i dont no how to turn down the fuel pressure without going into the hondata. is there a different way?

why not install the fpr that you have from jackson racing? give that a shot and see if you can bring it down a little.

the place that tuned it said that it is not work with the hondata. i dont no y that is but i thought i should listen to them.

anyone??