Having sputtering/stalling problems
 

Well as some of you may know from my previous post, I went racing sunday, on a day that probably couldn't have been any more beautiful. The first car down the track, a Supra, ended up in the wall just shy of the 1/8 mile. He couldn't have been 19 or 20 yrs old. So that delayed us running. They finally got the track open and I got my slicks bolted up, which are actually 27x10x15 stock car tires. Not bad for $30. I make my first run of the day, and it becomes my fastest time yet, 13.57 @ 100.6mph. Keep in mind this is at 4,100ft. So I hot lap it, stage, dump it at about 4000rpm, launches fairly good, and then during the 1-2 shift, it falls on its face, sputters, hesitates, and takes off. The rest of the way down the track I can feel it kicking and sputtering. Turn a 14.2 @ 97. So I dirve it around the pits for a few minutes and its doing the same thing. Throw the street tires on, take it on the highway, same thing. The 75 mile trip home, same thing. Whether its a little gas, or a lot of gas, any gear, any rpm, its sputters and hesitates.
Tonight after work I replace the plugs and wires. Gap the plugs at .35, Autolite 24's btw, and throw on a new set of wires. Take her for a ride, same thing. BTW, I also received my new sample tube from C&L today. Made sure I had one for 30's. Threw that on there with the plugs, and the same crap happens. Now its stalling at stop signs, and having problems starting back up, like its flooded. I have my 30lbs injectors in and running about 32psi so its not like I have a lot of fuel running in there.
Any help you guys can give me on this is greatly appreciated. I am open to any suggestions. I am supposed to go to the dyno this saturday in Tucson, but if its not running right, I am not going to try and drive the 300 miles to get on the dyno and have the car crap out on me.

Thanks
Chris

What mods do you have? Sounds like to me that you have to big of injectors. 30#ers are pretty big for most NA motors.

Sorry, i forgot that I took my mods out of my signature.

Typhoon intake, 255lph pump, Paxton Novi 1000 with 8psi, Full exhaust, 73mm C&L, 4.10's, and a few other things. I installed the 30lbs injectors because I didn;t have an adjustable FMU, and with the stock 19lbs injectors and the FMU, I was seeing over 100psi of fuel on the top end. It was cheaper to buy bigger injectors than it was to get a new FMU that I could calibrate as I went.

Chris

AAAHHH! Ok, well my suggestion would be to get a adj. fuel pressure regulator for one. Sounds like the car is starving for fuel, and computer is confused. In addition, get a good spark box like a 6AL or the like. Also, your mass air. You need to have a new sample tube installed in your C&L for your new 30# squriters. Hope that helps.

How long ago...
 

did you change your fuel filter? I know you've probably already thought of this, but a lot of the time it's the simple things you overlook.

You know it came to my mind to change it, just haven;t done it. I have the 255lph pump, and the right calibration tube for the 73. I also have an adjustable fuel pressure regulator, and have run anywhere from 28psi, to 42psi since I put these injectors in. It ran great for 3 days with 31psi, and ran great at the track on the first run. After that, its been crap since. This is getting annoying...

Chris

If it's not the fuel pump crapping out or an ignition problem, I'd pin it on the injectors.

I would say run the pressure to 50 psi for a week to see what happens. I run my stang @50. I don't have a SC but with the mods I have made the car needs more fuel. I run FMS 24#ers, now normally I would run them @ 45 psi, but I have the juice. Tried to run @ 40 psi for awhile, all I got was hesatation, bad idle, and lean pops under acceleration. With the 30's you might be able get away with less than 50. I'd say 45 plus psi for a week to give the comp time to learn. My guess is you won't be disappointed.

sputtering
 

I'd start with replacing the fuel filter. Mine has clogged up on me and had symptoms similar to yours.