Join Date: May 2002
Location: Fort Collins, CO
NX Digital Window/TPS Switch RPM readings...
I recently purchased the NX Digital Window/TPS Switch, and just got it installed this weekend. I went through the setup process, and everything went fine setting the unit.
I have a 96 Cobra, so when it came to the option to select the ignition system, I chose waste spark, which is what these cars use if I'm not mistaken. However, the RPM readings that the unit was displaying were WAY off, like showing 5000 RPM at idle, which was about 1000 on my tach. So I tried the other two options, Coil on Plug, and Distributor, to see if either of those were close. It turned out that the Distributor setting was within a few hundred RPM of my tach display, at least at idle(it showed 1100-1200 compared to 900-1000 on my tach).
Just curious if anyone has any input on this. I guess I'm concerned because the car uses a waste spark ignition (unless I've been mistaken on this), but that didn't match up with the switch. Is it different because I'm pulling the signal from the EEC as opposed to a coil pack?
Ultimately since the switch is activating and deactivating the nitrous system at set RPMs, I'm concerned about the accuracy of the RPM reading. If the Distributor setting is actually reading the exact tach signal, and my tach in the dash is a few hundred off, than no problem, but better safe than sorry. For what it's worth, I disconnected the fuel line from my nozzle, and the system did activate, but it's hard to tell the exact start and stop point from that test. Thanks for any thoughts or help.
Red 1996 Cobra convertible, 30,000 miles
Bama Eliminator Chip