This is my set-up..

2000 TA with NOS wet kit, fpss, wot switch, and timing tuner.
My problem is that when the nitrous activates its almost like its cutting on and off. When I had a 50 shot or so in there it didnt do it, but when I put the 75 in it started.

 

Have you checked your fuel pressure....
What plugs are you using...
How much timing are you pulling if any....
Do you know what your A/F is....

it sounds like the FPSS is shutting the system down...but the above questions will help us figure it out

 

I'm not too sure what the fuel pressure is, but I'm running TR6's with .36 gap. I'm pulling out 3 degrees of timing. By monitoring the narrowband O2's they were showing around .920-.940 mv.

The car is full bolt-ons with TR224 cam.

 

Oh yea, the car has SVO 30lbers and a walbro 255

 

Could 500 psi bottle pressure cause the surging?

 

YES...get it in the hot tub and warm it to about 900 then go try and see if it does it again...if not then it was just low pressure, next time warm it to 1050 and you really get the full potential out of it, i say try it at 900 first so your still rich but not enough to pop
(pressure will drop about 100 when you open the bottle and fill the line...

 

Your running a FPSS and don't know what your fuel pressure is?

Chances are thats it right there.
Monitor your pressure during a pull, and compare that to what your fpss is set to.

As far as 500 psi, thats wothless as well. Shouldn't surge though unless you just ran out.
Vinny

 

Since you don't know what your fuel pressure is doing you might try readjusting your FPSS.....

Remove the bottle from the car......Take the fuel line off the nozzle....have an assistent hold the fuel line into a catch can.....bring the vehicle up within the RPM window and activate the kit......slowly tighten the adjusting screw until the sytem starts to pulse/shut down, then back the screw off 3/4 of a turn.

 

good post.

 

All I have is a gauge mounted to the bottle, so I cant tell what the pressure is until the line is open..

 

I found FPSS so problematic that I kept a jumper handy. Since then I have wondered if they wouldn't be better to control the solenoid ground by use of a second relay that passed ground between pins 30 and 87 as opposed to having them have to deal with the current drawn by the solenoids.

 

i also have a buddy with an lt1 trying to spray a 1oo shot and is have the same problem only his bottle pressure is higher, he doesnt have a fpss, and it also feels like it is miss firing when he sprays it. what you guys think about this problem?

 

how accurate is tuning with narrowband. i thought a wide band is the only way.

 

trying to tune with narrowband is a waste of time IMO

 

Its the opti..........









sorry guys I had to.
P.S. I have an LT1

We will also need to know the current mod status.
Please find out the above information and we will be happy to help diagnose his issues.

 

ok the lt1 has p&p heads, p&p intake, 230-565 cam, full intake, full exhaust, ngk tr7, comp is around 11.5.1, 4.10s, msd blaster coil, mallory highfire 687 ign box, 1.6 rrs, harris speed works wet shot. bottle preasure was around 900psi, fuel preasure is around 45psi the whole time. when you first hit it, it feels like it is about to start hauling butt, but then the power feels like it drops maybe lower than what it is on motor. also starts to feel like it is missing.

 

Since it is a heads cam car do you know what the timing is set at...and are you pulling any when you spray....on the TR-7s what are they gapped at and are you showing any detonation on the plugs. You say they bottle pressure was 900psi...what are the HSW kits rated for psi wise. You say it feels like the car is missing, have you verified the miss. My old H/C setup you could not even tell it was spraying but it picked up 11-12MPH in the 1/4.

On the miss, is it back firing/popping out the exhaust?

sorry for all the questions but the more information you give the more we can narrow it down.

 

on motor the timing is set at 34 but for some reason it pulls 3 out under wot on motor. when i spray it im pulling 4. so when im spraying it, its like its pulling 7 out i guess. the tr7s are gapped at like 25 or 26. i had some tr6 in there gapped at like 35 or 36 and still does the same thing on the tr7 that it did on the tr6. im not sure of how to check the plugs for detination. the hsw kits are rated for 900 psi. how do i verify the miss?

oh and this is c5formula

 

check the nitrous lines to make sure the screens arent blocked.

 

if the car is pulling timing on motor...you have issues that need to be resolved with your current tune/tune up....the car needs to be set up w/no knock retard for an NA pass. It could be false knock but it is a risk I would not take.

Once you get that resolved you should be able to run the TR-6's gapped at .035 and pull 2-3* for a 100 shot.

PM sent....