Zex on Cherokee SRT8 problem

[El Chorizo]

Just sent this to support email via the contact us form, not sure if anyone will get it, figured I'd add it here see if anyone has any ideas.

I've got a ZEX kit on my SRT8 Jeep... the system works fine, once.

I have it hooked up to the TPS at the throttle body and I can program the system fine.

Once programmed, by hand I can activate the system at my set point on the TB butterfly.

However, if (even by hand) i move the TB butterfly to 80% then it remembers 80%.

If I then move it to 100%, it activated at 100% (and nothing lower).

Then, the next time, I can open the butterfly all the way and the system refuses to fire.

I had to "program" it before every pass at the track.

In other words, the system seems to remember the highest voltage it sees and refuses to keep it at my set point, and once it reaches maximum voltage, it never sees that "max" again and refuses to work until it's reprogrammed.

This is the 2nd unit I've ordered from you and both do the same thing, and it's the third unit I've used as we swapped with my buddies SRT8 Charger which worked fine.

Any ideas?

[amick]

If I understand you correctly you are attempting to program the box at 80% throttle and the NMU learns that but once it see's full throttle it will only activate at 100% throttle from there on out? If this is correct then the box is working just fine as that is how it is supposed to work. It will learn whatever voltage you teach it the first time but if it see's a higher voltage after that then it will re-learn that voltage. It is a saftey feature figured into the box to prevent premature activation.


I also have your e-mail just let me know if it is better to comunicate with you via here or the e-mail.

[El Chorizo]

Amick,

That would be fine, but thats not what is happening.

Once the TB opens 100% for the first time, it works.

Any subsequent opening of the TB at 100% fails to trigger.

Ie, for whatever reason it seems to see a higher voltage or remember a higher voltage after the first time then it will never see it again.

So, picture this scenario.

By hand, I open TB to 60% system fires @ 60%.
Open TB to 80%, system fires at 80%
Open TB to 100%, system fires at 100%
Open TB to 100% again, no firing ever again until box is reprogrammed.

It does this EVERY time.

So, if I reset the system and hold the throttle down I can get one pass. It will never function again until it's reprogrammed.

Mashing the throttle or opening TB by hand to 100% the system won't fire.

Know what I'm saying?

[amick]

Sorry fot the misunderstanding. I have couple questions for you that might help us to diagnose you problem. Can you tell me the color of the wire you have the system hooked into and are you using the resistor wire assembly that comes in the kit? Also can you measure the voltage reading you are getting at full throttle with the vehicle off and with it on please?