I got my 98 Z28 a few months ago. Automatic.
I put a set of LT headers, Lid and a 125 shot on it. Nothing else done
Took it to the track went 7.6 1/8 and 12.08 1/4. I was happy. I went right back out. nailed it. The went to hit my little button and it fell on its face. Too late I sprayed it and it back fired. I loaded it up and went home. Wasnt sure if it was just a nitrous back fire.
Went to another track the next week. I left the line hit the buttin everything was fine went 7.6 92mph. Went to go again. Took off same thing cut off and hit the button oops. busted my intake. Went home. Thinking Im having a nitrous problem. I dont want to spray it until I get eveything figured out.
Put a LS6 intake on it. Took it to the track. I was low on gas. Took off the line. It launched good. Then fell on its face. then took off. Blammed it on low on gas. Put some gas in it. Tried it agaon. Same thing. Went home. Started thinking tourqe managmnent.
Put dual exhaust, feebies, 4000 stall, and 3.73 gears. Went to the track. Its falling on its face even harder. It launches good. even is pulling the tires. ET streets and skinnies. As soon as it pulls the wheels it falls right on its face. Wont move I can hold the gas and it dont go. Then it wil feel like I get hit in the back and it takes off.
I go home. Tow it to CAM. Have it dyno tuned to get everything set and the tourqe managment taken off. First pull 301.5rwhp and 284.5 torque. Did alot of tuning and got 344.2 rwhp and 377.4 torque NA. Im happy with those numbers. with the 4000 stall and 3.73 gears and 28psi in the tires.
I took it to the track today. Did my burnout. Took off the line and it starts bucking. Trying to fall on its face. I let off the gas and try to go. then it takes off. I run again and it falls right on its face. Then I try it with out a burnout. Just clean the tires. I cut a 1.84 60 8.110 1/8 and 12.6 1/4. It bogged just a little. Just spun the tires. SO I realize that without the bunout Im not cutting off as bad. I want to get this problem fixed. So I can spray it. Any ideas on whats wrong?

 

you need to get a fuel pressure reading.while the car is under load as the fuel pump circuit on these carscan be gremlin infested.a fuel and nitrous gage on the a pillar is what i run.dude if your going lean on the nitrous next step is meltdown! Is nitrous shot wet or dry?

 

The nitrous is a wet kit. I ran a report on the car and the pump has been changed 3 times in the car. Maybe thats the problem.

 

check the main hot wire to the fuel pump near the tank in the rear.May be brittle from heat as well as starting to melt. check the connectors that attatch to the under body right above the rear end drivers side" little black plastic" connector block.

 

its been a few years since i did my walbro inline fuel pump install but if i remember correctly the wire is grey with blue stripe.Contact S.L.P. and I believe they sell a larger guage hot wire kit just for your problem, as well as do the walbro 155 inline install and keep an eye on fuel pressure and nitrous pressure in high end of your pass on lafn gas.you gotta run fuel pressure guage,nitrous guage,and a bottle heater to be safe as well as efficient.

 

also let some air out of those et streets they work best at about 14 P.S.I. the 184 sixty foot is terrible.When the tires and suspension are working together on a stock suspension you stillshould see a high 170 sixty foot in mid twelves.

 

Well it lauches good. It pulls the wheels and then dies. I have it on video. And I can pause it when it launches. It looks great then I unpause it. And it falls. It wont move and then it just takes off. I just ordered a new set of wires. Im checking all the connections. Installing a intank walbro pump. I will let you know how it does then. Thanks for the help.

 

heres a vid of it acting up. Remember it is floored the complete time. You can see it launching good then falling.
http://members.scfyb.com/zeeya/zeeya.wmv