TPS and nitrous
Allmachtiger
02-27-2003, 08:36 AM
Ok the nitrous works, believe me it works.
But I got an annoying problem that I think anyone without nitrous and help me on. This Zex system I have uses the TPS (throttle position sensor) to sense when the engine is at WOT (wide open throttle). Well you have to "learn" the NMU (contains the selinoids and what not in one box) to understand when your throttle is at WOT, based on voltage of course. Well you have to tap into the particular wire that sends an increased voltage curve as you press the gas pedel down (blue wire). This is the issue...sometimes when I nail it, the nitrous does nothing. So I checked under the hood and saw that at WOT the NMU wasn't even responding. So I reset the NMU to learn when I'm at WOT. After resetting several times I can get the nitrous to work for about 5 good shots. But then if I turn the engine off for 30 minutes or just out of the blue it won't work. Also sometimes, when I reset the NMU it shoots nitrous into the intake JUST when I flip the switch and NOT at WOT. This is very bad.
When it works it works like a beast. But its very irratic. Now heres the part anyone can help on. Doesn't this sound like some bad connection between the Zex NMU and the TPS? Maybe some crappy wire splicing by my part? I used this cheap blue wire crimp that Zex supplied and my guess is that its not making good contact. I know my vacuum hoses are all tight and working because the engine would run like crap if they wern't. Plus the nitrous probably wouldn't even work because its all based on bottle and vacuum pressure. So what do you all think?
But I got an annoying problem that I think anyone without nitrous and help me on. This Zex system I have uses the TPS (throttle position sensor) to sense when the engine is at WOT (wide open throttle). Well you have to "learn" the NMU (contains the selinoids and what not in one box) to understand when your throttle is at WOT, based on voltage of course. Well you have to tap into the particular wire that sends an increased voltage curve as you press the gas pedel down (blue wire). This is the issue...sometimes when I nail it, the nitrous does nothing. So I checked under the hood and saw that at WOT the NMU wasn't even responding. So I reset the NMU to learn when I'm at WOT. After resetting several times I can get the nitrous to work for about 5 good shots. But then if I turn the engine off for 30 minutes or just out of the blue it won't work. Also sometimes, when I reset the NMU it shoots nitrous into the intake JUST when I flip the switch and NOT at WOT. This is very bad.
When it works it works like a beast. But its very irratic. Now heres the part anyone can help on. Doesn't this sound like some bad connection between the Zex NMU and the TPS? Maybe some crappy wire splicing by my part? I used this cheap blue wire crimp that Zex supplied and my guess is that its not making good contact. I know my vacuum hoses are all tight and working because the engine would run like crap if they wern't. Plus the nitrous probably wouldn't even work because its all based on bottle and vacuum pressure. So what do you all think?
GTStang
03-02-2003, 12:47 AM
If you wanna know if your wiring is good just check for voltage at the end terminating in the NMU. See if it corresponds to values for the TPS that will be listed in a chilton's manual. If it's ok, make sure your NMU is mounted securely and nothing is hitting it or it's moving and keep it away from heat. If all else is ok you may have a bad NMU
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