Had me some fun last night, but something happened that has me concerned. This happened 2 times last night out of a lot of times. When I launched it last night, my car stuttered and I heard a couple of soft faint boom boom. There's no smoke at all coming from tail pipe and this only happend twice last night. All the other times it doesn't happen. When I was on the highway and kept dropping it to 4th at wot at 7psi, it runs like a bat out of hell. Then other times when I launched it at wot, it doesn't happen. Could it be my spark plugs?

or you could be running too rich

96RS ~ full 99GS Special Edit. body conversion, aem cai, greddy header, afx pulley, B&M SS, magecores & NGKs, A/F and Volt guages, Sparco Torino Seat, illuminas, prokits, ingalls camber, gunmetal GS rims, ST Sways, STBs, lower rear tie bar, Sony Xplode head, Xplode 10 disk, Boston Components, 2 Kenwood amps, 12" MTX sub, a shit load more.


97GSX ~ 18psi~ Ported/Clipped 15 degrees Frank 2 w/46trim, Ported Exh. housing, Tial 40mm External Wastegate with discharge tube, Ported O2 housing, 3" downpipe, 3" Straight Pipe, Apex N1, fake cat, K&N FIPK, Greddy IC Piping, Type S bov, S-AFC, Profec B, Greddy TT, Slimline Fan, RRE Catch Can, Greddy Big FMIC, ND 660s, Walboro 190lph, ACT 2600 w/street disk, clutch SS line, lighten flywheel, removed cruise control line, Greddy EGT, Coolant, Boost Gauges, motor mount inserts, Magnecor & plugs, greddy oil cap, greddy radiator cap, and free mods. To all the haters _|_ tia

Make sure your fuel mapper has a good connection to your MAP sensor. After that check that your plugs are good and your wires are good. ANd running rich can also do that to you like Kory said. Make sure you are not running too rich. Running rich does cause backfires sometimes.

at 7psi I'm running no more than 95psi of fuel pressure at wot. The a/f guage shows from .92 sometime to .94. What should my fuel pressure be and the ideal o2 voltage at that psi of boost?

Ok guys this is weirder. When it does stutter it only stutters on 2nd gear at WOT and the a/f shows .98 sometimes and .92 sometimes. On the highway it's a killer. on 4th and 5th gear it shows .90-.91 at wot. What should I do?

bump!

and BOOOM! it happened.

Something was wrong. If it stuttered at WOT, it was either because you had already broken something, or because something was fucked up concerning your fuel system or your boost control.

The only time i ever stuttered at WOT was due to overboost from an incorrectly plumbed wastegate. too much air, not enough fuel = cracked pistons.