Nitrous Oxide Installation | Tuning | Products
Sponsored by:
Sponsored by:

Trouble Setting FPSS - Help Please!

Thread Tools
 
Search this Thread
 
Old Sep 5, 2012 | 06:27 PM
  #1  
1quickTransAm's Avatar
Thread Starter
TECH Apprentice
iTrader: (4)
 
Joined: Apr 2008
Posts: 393
Likes: 0
Default Trouble Setting FPSS - Help Please!

I was going to spray for the first time tonight, but I am having a hard time setting my fuel pressure safety switch. I tried setting it by these instructions from Chris at Nitrous Outlet (below), but it's not acting consistently. The solenoid will click at one set point, then I'll click the micro switch again and it will spray fine and I can turn the setscrew two or three times and it still keeps spraying. What am I doing wrong? Any tips? I really wanted to spray tonight.

Instructions I'm following;

*If you need the FPSS adjusted i'd suggest you take the nozzle or plate and out it in a bucket. There is a rubber nipple on the top of the FPSS that you will need to remove to reveal a set screw. Now you will need to activate the system and as the fuel is flowing out of the nozzle into a bucket you will need to turn the screw clockwise ( to increse the set PSI ). Only do it in short 5-8sec bursts so that way you're not heating the noids up for no reason. As you are turning the set screw once the fuel starts to sputter out of the nozzle then you will need to stop turning the screw and now turn it about 3/4 to a full turn counterclockwise and that should have the FPSS set to the flowing fuel pressure.
Reply
Old Sep 5, 2012 | 07:22 PM
  #2  
Burrhos's Avatar
On The Tree
iTrader: (3)
 
Joined: Nov 2007
Posts: 181
Likes: 2
From: Tampa, FL
Default

Where is your FPSS located?

Mine is teed into the fuel feed to the rail.

I just used a test light to check which side had constant ground and which had intermittent ground when the switch was thrown. Once I figured out which side was constant ground, I put the test light on the opposite side and turned the **** until the light came on, indicating that the switch was seeing pressure and completing the circuit when the car is running.

I turned the car off and checked the same pin and sure enough, it had no ground. I had my wife start the car while I held the test light in place and as soon as the car fired up, the test light came on so I was/am convinced it was set appropriately.

Here is how my fpss is setup.
Reply
Old Sep 5, 2012 | 07:56 PM
  #3  
1quickTransAm's Avatar
Thread Starter
TECH Apprentice
iTrader: (4)
 
Joined: Apr 2008
Posts: 393
Likes: 0
Default

Mine is located just before the fuel solenoid.

Using a test light seems like a good idea. The thing that concerns me though is that I was doing it based on observing actual solenoid action and fuel flow, which should obviously be accurate, but it seemed all over the place...

Not what I was expecting.
Reply
Old Sep 6, 2012 | 07:01 AM
  #4  
Burrhos's Avatar
On The Tree
iTrader: (3)
 
Joined: Nov 2007
Posts: 181
Likes: 2
From: Tampa, FL
Default

How old is the fuel noid?
Reply
Old Sep 6, 2012 | 07:14 AM
  #5  
1quickTransAm's Avatar
Thread Starter
TECH Apprentice
iTrader: (4)
 
Joined: Apr 2008
Posts: 393
Likes: 0
Default

Not sure... bought the basic kit (bottle, lines, solenoids, purge, FPSS) used from someone on this forum. All the rest I bought new. I did disassemble the solenoids to inspect and tested functionality, but not sure how old they are.
Reply
Old Sep 6, 2012 | 07:29 AM
  #6  
Burrhos's Avatar
On The Tree
iTrader: (3)
 
Joined: Nov 2007
Posts: 181
Likes: 2
From: Tampa, FL
Default

If the fuel isn't flowing steadily out of the fuel noid then your FP is off or there is a restriction in the noid.
Reply
Old Sep 6, 2012 | 09:04 AM
  #7  
1quickTransAm's Avatar
Thread Starter
TECH Apprentice
iTrader: (4)
 
Joined: Apr 2008
Posts: 393
Likes: 0
Default

It does flow steadily at some FPSS settings, but clicks on/off rapidly at others. I expected this from the "how to" write-up, but it is the inconsistencies that concern me. It will click on/off at one setting, then I'll close the microswitch again at the same setting and it will flow fine so I'll turn the set screw two or three times and it still is flowing.

I'm not sure why the cut-off point isn't more consistent...
Reply
Old Sep 6, 2012 | 09:08 AM
  #8  
Burrhos's Avatar
On The Tree
iTrader: (3)
 
Joined: Nov 2007
Posts: 181
Likes: 2
From: Tampa, FL
Default

Oh, I misread what you were saying. The fuel is consistent but the point at which the microswitch activates/deactivates is not. I understand. Is the switch new? Perhaps it's on the fritz?
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-1

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-2

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-3

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-4

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-5

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-6

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
story-7

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

 Verdad Gallardo
story-8

10 Camaros You Should Never Buy

 
story-9

10 LS Engine Myths That Refuse to Die

 Verdad Gallardo
Old Sep 6, 2012 | 10:28 AM
  #9  
1quickTransAm's Avatar
Thread Starter
TECH Apprentice
iTrader: (4)
 
Joined: Apr 2008
Posts: 393
Likes: 0
Default

^ Exactly!

No, its used so I really don't know its history. I got it used with the solenoids and bottle but it all looked almost new (even when taking apart the solenoids). Pretty much everything else is new.
Reply
Old Sep 6, 2012 | 10:29 AM
  #10  
Burrhos's Avatar
On The Tree
iTrader: (3)
 
Joined: Nov 2007
Posts: 181
Likes: 2
From: Tampa, FL
Default

I'd buy a new one. They're cheap enough and important enough to warrant the necessity in its functioning correctly.
Reply




All times are GMT -5. The time now is 07:34 PM.

story-0
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-1
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-2
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-3
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-4
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-5
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-6
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE