I just installed a ZEX kit on a 2002 trans am and am having some problems. First, with the TPS wire spliced in with the signal wire coming from the TPS the car idles up at around 1000 rpms and the car shows to have 5% throttle applied. When the car isn't running but the ignition is on it shows to have 0% throttle applied. I modified the TPS sensor to make it adjustable hopeing to compensate for the 5%, but it didn't. The voltage reading dropped on the scan tool, but with the nitrous wire spliced in it still idles high and shows 5% throttle at idle.

I found someone else on here who had the same problem and ZEX's solution was to add a resistor in that wire. WTF?

Also, I'm having problems with the solenoids activating as soon as the arming switch is turned on. Theres only 3 wires, one going to the switch to 12 volts, one to ground, and one to the TPS. How can the solenoids activate when the TPS I know is only showing 5% throttle? I can't even calibrate the thing for full throttle because half the time the box will not light up.

 

I Thought I Was Having Problems With My Zex Kit Last Year And They Sent Me A Resister. Well, It Ended Up Being My Tps Wires Were Old From Moving Them Around. That Solved My Problem.
It Sounds Like Your Not Connecting The Wires Correctly For The Tps. Sorry, Thats All I Can Help With

 

Make sure all three wires are hooked up properly... 12v to 12v, WOT to TPS, ground to ground. Turn the car to Key on / Engine Off position. The light on the zex box will turn a certain color or flash or something, I dont remember, but at that point, press and hold the gas pedal to the floor for 5-10 seconds, then release. It has to do with calibration, not sure why, but just try it and see what happens. This was on an lt1, but it should work the same for ls1 I'd think.

 

I agree with the above. I don't think your tps wire is hooked up properly.
You should have it hooked up to pin #24of your computor.
That should take care of your problem.

 

I appreciate the help guys but I'm pretty sure that I have the wires hooked up right. Red goes to switched 12V, black to ground, and the TPS wire I have going to the blue wire at the TPS sensor. It shouldn't matter if its hooked at the tps sensor or at the pcm, as long as its on that wire. The three wires at the tps sensor are a low voltage reference, a 5 volt reference, and the signal or output wire. I even checked the wire I spliced into with a dvom just to check and see that it was the output wire.

The box will no longer light up at all, and everytime the system is armed with the switch the solenoids will open. Obviously if the solenoids open when the switch is armed they must be getting power and ground.....but they shouldn't open when the tps is showing to be 0% throttle.

After speaking with one of the ZEX tech guys, it looks like we are going to have to send the box back.

 

i have a similar problem thats happenin to my 97 z28, it will idle at 1000rpms and for some reason it sounds like a deasil truck from the inside of my car, the worst thing is when im drivin and floor it, it wont downshift into the lowest gear as if its not detecting WOT.. i just got it installed and im bringing the car back to the shop so they can try to fix it

 

i had to send two of my boxes back before i had one that actually worked.. i think this is a common problem for the zex kits

 

Well after checking things over and over I finally reallized that the solenoids would activate at an idle and if the throttle was applied it would shut them. To calibrate it, I just held the throttle wide open...pressed the black button....then let the throttle go back to the idle possition. When the light started blinking from red to green I opened the throttle back up to wide open and then shut the switch off. I don't know why, but it seems to work the opposite of the way the instructions describe to calibrate it. Either way, its working now as it should!