phatmobile98

First off my car is a 1998 Z28 LS1. Major mods done - heads/cam package all the bolt-ons (incl. SLP LT headers), and a built 4L60E tranny w/3500 high stall torque converter.

Just recently I downsized rims from 19's w/street tries to 18's w/nitto DRAG RADIALS. I could NEVER get full traction on launch until now...but here's where the problem is. Almost everytime I floor it from a dead stop and begin to grab, the car takes off for a split second and then makes a loud whine noise for about 1/2 a second and then sputters with almost ALL power being shut down. The car doesn't turn completely off though, because when I let go of the gas a little it everything goes back to normal -- and I'm on my way. This ONLY happens when I get traction from a launch! When I spin (cold-tires) from a launch OR even when I go from a roll and get traction, everything is ok at full-throttle. WHAT COULD BE DOING THIS?

The only problem that I am aware off on my car right now is an o2sensor code tripping the SES light: bank 2, sensor 1 (pass side front). I replaced the o2 recently, but the light still comes on and I do think that I’m running a little rich. Other than that I don't know of any other problems. ??

I've done some research and the only thing I can think of causing this is my fuel system. I have the 28# injectors cause I have a 98, and I'm only putting out at most 380-400rwhp/tq, so I don't know why the fuel system could be going bad. I do have almost 90,000 miles on the car though.

I also read about this:

Fuel Cutoff Mode
The PCM cuts off fuel from the fuel injectors when certain conditions are met. This fuel shut off mode protects the powertrain from damage, and improves drivability. The control module disables the injectors under the following conditions:

The ignition is OFF (prevents engine run-on)
The ignition is ON but there is no ignition reference signal (prevents flooding or backfiring)
The engine speed is too high (above red line)
The vehicle speed is too high (above rated tire speed) (Does not apply to Y Cars)
During an extended, high speed, closed throttle coast down (reduces emissions and increases engine braking)

Could this be what's happening??
ANYONE HAVE ANY INPUT ON THIS? PLEASE - I NEED ALL THE HELP I CAN GET. THANKS!!

XLR8NSS

iTrader: (4)

Could be that your battery hold down is loose and letting the battery move on a hard launch causing it to short out on something. I've heard of others having similiar problems before because of this. Go check your battery out and see if moves any or if anything has burn marks where it's shorted out.

CHRISPY

Ditto, your battery is probably falling on launch and shorting on the metal under the car. Happened to me, what a PITA

WicketMike

iTrader: (13)

how big is that cam? it might be upshifting into 2nd gear right away

DrkPhx

iTrader: (15)

Happened to me too. The battery flipped forward and the positive terminal was shorting against the A/C bracket. A $15 battery strap fixed that problem.

ss1le02

iTrader: (4)

Battery. The same thing was happening to a friend of mine when he would launch.

PREDATOR-Z

If battery secure,
I've experienced similar symptoms on launch and it is a tuning thing with Hi stalls. It is called trans abuse mode (linked to TM) and what is needed is to increase the parameters so the engine doesn't drop to 0* timing under extreme peak torque conditions. Effect of torque management.

mrr23

iTrader: (3)

my battery hold down tray broke during a launch also. dash would go out. had a backfire once. friend of mine at the track had his battery die on him. so, i went to take mine out and saw where the positive terminal was hitting the AC accumulator clamp. you could see the arc marks.

sevanseriesta

iTrader: (34)

I can not believe this.......A battery cause all of this huh.....Boy am I glad that i read this thread....I am getting ready to put in a trex cam and my battery is not secured very well.....Going to the store now to get something to secure that bad boy