Ok, I'm stumped. I've got some sort of electrical problem and I can't reproduce it. Let me give you the basics. My setup consists of:

Nitrous Express Maximizer II controller and the direct port NXL kit. Links below (you can find better descriptions in the installation docs):

Maximizer II
http://www.nitrousexpress.com/produc...ils.php?id=335

Direct Port NXL kit
http://www.nitrousexpress.com/produc...ils.php?id=665

Ok, now here's what happens. When my nitrous is activated by the controller, my gauges all go nuts. I even get notice from my EFI Live that it's lost connection with the PCM. What's interesting is I can't reproduce the problem in the garage. If I can reproduce the problem, I can systematically change grounds, connectors, etc until I find the source of the problem. Unfortunately I've not been able to. Let me explain.. I disconnected the dual 8 pin connectors that you see circled in yellow. These connections provide pos/neg to the 2 sets of 2 (fuel/nitrous, circuled in green) solenoids from the progressive controller. I connected my multi-meter to the controller side of the cables where I disconnected them. I then reprogrammed the controller to kick off at 3000 and very low TPS. The result was a good clean "simulated" hit. It registered a little over 14v on the multi-meter and no goofiness on my PCM or gauges.

Now two things in this simulation are true. The system THINKS the kit is active, but no power is getting to the real solenoids and the TPS is not really at WOT. After not being able to reproduce the problem, I used my ohm meter to check continuity on all 4 solenoids wiring. When I check the pos/neg ends where I disconnected them, I get a consistent 1.4 ohm reading on the nitrous solenoids and .5 ohm on the fuel solenoids. Assuming this tells me that the circuits are good, that only leaves me with a difference of WOT.

Where the heck to I do from here??? If I can't reproduce it, how can I fix it!

 

First question is, how old is the battery? Sometimes when batteries are old and really aren't holding a charge, they don't like large spikes in draw. I would suggest at the very least have the battery tested.

Second, have you gone back over your wiring on the system? I would start looking at where you're grounding things and where you're pulling power from. If any of them piggyback onto the main factory harness, I'd look into a feedback issue.

Generally though, when the gauges go wacky its from a weak battery...so start there.

Nick

 

Thanks for the input. The battery is only a couple of years old. Of course that doesn’t mean it can’t be bad. I did a lot of connection testing/moving that I didn't list in my original post. I don't piggyback for any of the main power / grounds, but I do have a little misc linkage like to the status LED. I'm using the cig lighter power. I suppose I should move those to a dedicated source.

I'm no electrician, but would I be correct in assuming that it's possible I can't reproduce the problem because my multi-meter doesn’t draw the same amperage as the noids? I didn't think about that until your comment about the battery.

I suppose if I want a full test, I’d have to find a way to "cap off" the fuel and nitrous connections so when the system activates no added fuel or nitrous is introduced to the car but the noids would become part of my test. This would be easy to do for the nitrous since there is a single line in I can cap. The fuel will be another story.

 

A little update. I think I found the source of the problem. For those who found this an interesting problem.... After spending $50 for caps, I disconnected the fuel and nitrous lines and capped them off. This permitted me to simulate an active nitrous hit at low RPM without actually introducing nitrous and fuel into the system. I also configured the Maximzer to perceive TPS as being WOT at about ¼ throttle and to activate the nitrous modules at 1000RPM and 50% TPS. This allowed me to activate the modules at a very low threshold. What I've noticed is that I don't have a stable connection to my TPS and RPM cables. I think what I’m seeing is the reverse of what I initial was thinking. It’s not the noise or feedback causing these two gauges to fluctuate. I've used vampire clamps to tap into RPM and TPS for my Maximizer and I believe these two connections are causing my problems. Because the Maximizer isn’t getting a stable RPM and TPS reading, it’s “flapping” the nitrous on and off. I’m sure the voltage deviation caused by the bad connection isn’t making the PCM happy ether.

I'm going to replace those connections this evening and re-test. Keeping my fingers crossed.

 

Please...keep us informed.

 

I have seen where these vampire connections cut to many of the strands and the wire can no longer carry the load. the tps wire is only 5 or 6 strands. use a soder connector and see if that helps

 

I like the solder idea, but for the moment, I've used a different vamp connector. I took my car to a low traffic industrial road and gave it one good run (without the fuel/nitrous) connected and the active solenoids didn't present a problem to my PCM this time. Of course that was only one test. It was too hot over the weekend (105 in my garage) so I didn't reconnect my fuel and nitrous, hence, no final "real" test. I'll try to do that this week. If I still have similar results. I'll remove the vamps and use solder.

One more interesting note. I'm not sure if it's normal or not. I modified my program a little more to permit the activation of my kit without even running the engine (time based activation rather than RPM based). Anyway, I notice with each activation I would hear a little flutter of something behind the dash. No, it wasn't the noids opening/closing. Those sound of the noids is unmistakable. The only other time I've heard something similar was when the battery got weak and I tried to start the car. Strange.. Couldn't figure out what was making the sound and why it would make it when the kit was active.