NOS and F.A.S.T. what am i doing wrong?

[96Z28SS]

I have the negative side of the relay wired to the ECU
I have 12v wired to battery
I have 12v switched to my arming switch
I have the wre hooked to my NOS solenoid from relay

I have 12v switched to the other wire on the ECU

WHy is it that when I hit the arming button that it sprays?
It seems as though the Fast is constantly grounding the relay its not waiting to hit my parameters.
with the car off and the key on it sprays.
I cut the solenoid wire and took the car to the parameters and it dumped the fuel set per the parameters, but the NOS is activated per the arming switch which I know is wrong.

Is there something wrong with my FAST ecu that its constantly grounding the relay when it should only ground it when it hits the parameters.

Rob

 

[TurboNova]

Originally posted by 96Z28SS
I have the negative side of the relay wired to the ECU
I have 12v wired to battery
I have 12v switched to my arming switch
I have the wre hooked to my NOS solenoid from relay

I have 12v switched to the other wire on the ECU

WHy is it that when I hit the arming button that it sprays?
It seems as though the Fast is constantly grounding the relay its not waiting to hit my parameters.
with the car off and the key on it sprays.
I cut the solenoid wire and took the car to the parameters and it dumped the fuel set per the parameters, but the NOS is activated per the arming switch which I know is wrong.

Is there something wrong with my FAST ecu that its constantly grounding the relay when it should only ground it when it hits the parameters. Rob

Just a stupid question but do you have the right relay? There is a normally closed one and a normally open one. They are both labeled the same way and there is no way to tell with out a test light.

 

[96Z28SS]

What should I have for a relay? normally open or normally closed?

 

[TurboNova]

Originally posted by 96Z28SS
What should I have for a relay? normally open or normally closed?

I would suspect that right now you have a normally closed relay and the power is just looping between the power wires. The Fast box just triggers the relay if it is a normally open relay.

If I were you I would hook wires to the back of the relay and go to your battery with a test light and touch different wires to the battery and with a test light find out what wires are hot then you will understand how your relay works. You will most likely have a loop in the hot wire going from your battery post to the trigger wire.

When you get another relay make sure it is a normally open one.

Like for example my trans break relay is a normally closed relay and when the button is pressed then the circut opens and the nitrous would not work, when the trans break button is let go then the nitrous would start working.


What you need is a normally open realy so that when the fast box triggers the realy, the circut closes and nitrous turns on.

Just a thought, use a test light, your relay, some extra wire and your battery to find out how your relay works. You will not fry the relay if it is hooked up wrong.

 

[96Z28SS]

okay I'm confused

 

[TurboNova]

Originally posted by 96Z28SS
okay I'm confused

Ok, just go get a 5 prong relay normally open and try it.

 

[Otto J]

On a 5 pin you do not use the center pin for what you are tryin to do, THe center pin is directy power thru

 

[berrelauto]

Are you using a FAST NOS harness ? If so do this simple test, Turn bottle off than unplug nos harness at the ecu plug, Key on engine off, set arming switch on. Are solenoids on ? If yes you have a harness problem, If no than ground terminal B of the NOS harness if solenoids go on the harness is ok and the problem is in the ECU. I had this problem once on a customers car.

 

[96Z28SS]

Originally posted by berrelauto
Are you using a FAST NOS harness ? If so do this simple test, Turn bottle off than unplug nos harness at the ecu plug, Key on engine off, set arming switch on. Are solenoids on ? If yes you have a harness problem, If no than ground terminal B of the NOS harness if solenoids go on the harness is ok and the problem is in the ECU. I had this problem once on a customers car.

No i'm not using the F.A.S.T NOS harness I was just using a Bosch relay. Wiring it to the NOS connector on my harness.
I can't get it to arm and ground the solenoid when it reaches the parameters. It seems to be grounding the solenoid all the time.

With the car off and key on I set arming switch on and yes it sprays nitrous.

 

[berrelauto]

Test the (B) terminal white wire on the NOS plug to ground with engine on & off, no ground should be present. If there is ground than you have a possible ECU problem.

 

[96Z28SS]

Yes I think, there might be a problem with the ECU I will check the ground today. I think it may need to go back to FAST.

 

[96Z28SS]

Well it was the FAST ECU cause I borrowed on from a friend and downloaded my tune and started the car and I armed the switch and it didn't fire the solenoid I strapped it to the dyno and it kicked in just when it was supposed to.
Made 551 rwhp and 618 rwtq