I installed a wet plate system on my 97 C5 about a month ago and I cant figure out why it isnt working. After completing installation we put in a fuel jet for 100hp and went out to see if it worked or not figuring if everything worked the extra fuel would bog down the engine and then we would know if the fuel was working. well we tried and nothing happened so since then i have bypassed the FPSS, checked wiring, checked fuses & checked the solenoids, everything seems to be in working order. So now by process of elimination I assumed i programmed or wired something wrong with the window switch. Its a dynotune 2 stage window switch. I'm only using stage 1 right now but stage 2 is wired for the future use. Using the diagram for the window switch i wired the green wire (tach signal) to pin 35 (White wire) on the blue connector from the computer (behind passenger front tire) & wired the blue wire (TPS) to the drk blue wire coming back from the TB. When the car is at idle i checked the window switch, it reads 0.0.L If i hold in switch 1 on it reads 0.4 at idle. So its reading 400 rpm at idle from what i can tell. I went through and checked all my settings, they are as follows:
Step 1: 008 Tach Setup
Step 2: 001 (Gear Lockout)
Step 3: 03.1 Ch. 1 Activation RPM
Step 4: 05.7 CH. 1 Deactivation RPM
Step 5: 03.7 Ch. 2 Activation RPM
Step 6: 06.3 Ch. 2 Deactivation RPM
Step 7: 002 (TPAS Mode)
Step 8: 8:4.5 TPS WOT Setting

To me this setup seems right. Sorry this is so long but im out of ideas as to what could be the culprit. Thanks in advance for any help.

 

Off the PCM tach input you need to set Step one to 4 (don't ask me why), once you do that it should reflct the correct RPM when you hold button 1 down. Your car is not really idling at 400 RPM is it?

 

No it doesnt idle that low, It idles between 7-800 rpm. I'll give that a shot tonight and see how it goes, Thanks

 

I've never worked ona 97-98pcm. But is that the correct pcm connector for the tach output?

 

Looks right, I use ls2.com to check pinouts.

http://www.ls2.com/boggs/torques/enginetorques.htm first 1/3 of page has links based on years to the pinouts.

 

If nothing else could you also post a drawing of your nitrous wiring?

 

If changing step 1 to 004 doesnt work I'll post up a wiring diagram that i followed while wiring the car.

 

you do have to set it to 4 cylinder mode

 

Ok so this weekend i checked wires and bought a new relay and checked it and it works, changed step 1 to 004, took it out, got it to WOT, let it shift gears even and kept it at WOT and nothing All the steps are like i listed originally except for step 1 being 004. I have a #28 jet in the fuel which by the manual is a jet for 100 hp. I would think at WOT that if the fuel engaged it would bog my engine down and i would know the system is functional but it doesnt. the only thing i can think of is something isnt right with the window switch or that wire for channel 1. i ran my own wire for testing to the relay and grounded it and relay worked and solenoids clicked. So any other insights would be helpful and if there is a better way of testing this id be open for any suggestions there as well. Can you test the car in park and just put the pedal to the floor and have the fuel line dispense into a bottle or something? Thanks

 

did you verify the WS is reading the correct RPM now..?

 

yes at idle the WS reads .8-.9 which is consistant with the tach inthe vehicle.

 

Did you program the WOT for about 3/4 throttle? Perhaps if you programmed it for being floored its not seeing the full voltage. Try 3/4 throttle for WOT programming, are you using the Trick Performance instruction set?

 

Try starting w/ it set up for just the most basic settings to test wiring. If it works, add back one piece at a time to find your problem area.

Disable WOT settting and gear lock out and then set activation RPM to 1200 and deactivation at 1500. Disconnect fuel line and place in jug or bucket. Start it up, arm the nitrous and give it a try. If you don't get fuel here, you know something is not wired right or you have a defective part somewhere.

If that works, turn first gear lockout back on. Rev through 1500, let revs drop back down below 1500 and it should flow fuel again.

Then your left w/ the WOT.

At these levels the FPSS shouldn't create an issue but for trouble shooting I would still bypass it.