Heres the deal. I have an nx wet kit with all the goodies. Nx tps switch, genx-2 kit, and an mds digital window switch.

Went to the track today, on the way there did a 60roll with a friend and it worked beautifully. Get to the track do my burn out, stage and launch and it hits then falls on its face, comes back on the falls on its face a couple seconds later. As this is going on i look at my window switch which shows the rpm reading and it is showing 0. When it cuts back on it shows the rpm I am at.

Whats weird is it only does it from a dig (I've done a couple rolls with it and its done just fine) and the window switch reading 0. The system is still active cuz the light on the tps switch is still on.

Anyone give me any info on where i can start looking to correct the problem?

 

Are you running the fuel pressure safety switch? If so, you may have the cut-out pressure set too high. If you fuel pressure dips slightly it may trip the switch. You may also be running out a fuel pressure if your fuel demand is too high and need to get a bigger pump.

 

Since your window switch is showing 0 rpm at the time of the failure, the obvious place to check would be the tach feed line to it....sounds like an intermittent connection to me.

 

I thought that to but that wouldn't have anything to do with the msd box showing an rpm of 0. I have a bigger fuel pump also


I'm thinking tac signal also. Its been checked once before and everything appeard to be connected properly.

Anyone know if there is a voltage reading it should get so i can check it with an ohm meter?

 

How are the connections made? Crimped, soldered (preferred), twisted and taped, etc.?

You can verify it with an ohm meter without having the power on. If you use a volt meter, I'd imagine you'll see something in the 2.5v range since it cycles on/off and the meter will read the average, but literally anything present will tell you it's connected. Try having someone watch the window switch display (assuming you can't see it from the engine bay) and wiggle the wire slowly and see if the display goes in/out. Check all the other connections as well.

 

It's probably the window switch. I had the same problem with mine, and swapped in an MSD analog window switch and the problem went away.

 

I do beleive that they are crimped and soldered.

Thanks i'll see if I can do that when I get home today. I have an msd 6al box and i'm told there is a male connector on the side of it that i might be able to get a tac lead off of. So i may try that as well.

 

That doesn't sound to promising. Did you ever figure out what went wrong with the box. Or did you just throw it in the trash?

 

UPDATE:

pulled it apart today and found that the tach connection is good. we pulled on it wiggled on it and tested it with an ohm meter. seems like we are good to go there.

had a theory to try out. went out with the bottle closed but with the nitrous system armed from a stop we went WOT and during the shift the msd box went to 0 and stopped working.

turned the switch off with the bottle closed and repeated it and the msd box worked just fine.

Any ideas as to why this might happen. the switches are the nx switch panel with the arm, purge, and bottle opener switches. They are made by carlingswtich.

 

How is your heater transducer wired?

 

it is part of the arm switch. rock it forward and the heater comes on, rock it back and the system is armed.

 

http://www.nitrousexpress.com/Instru...witchpanel.pdf

what my dad thought might be a little weird was it didn't matter which way the switch was flipped ( either on the heater or on arm) the other side still had power. Like if it was on the heater the arm side of the switch still had power and vise versa. the only time it wasn't like that was when the switch was in the off position.

 

I'm not familiar with that switch setup, but have you tried contacting NX? It seems like either your heater stuff is miswired, or the switch panel is. You actually have a pressure switch on the bottle right?

It would help if you could take some photos of the various areas (bottle/heater/switch panel), or list all the wires and where they go.

 

I guess i should mention that this set up worked last year and nothing has been changed on it. This all started last nov when i went to the track,

what would you like pics of specificaly?

Yes there is a guage on the bottle itself, the heater works fine.