Slight wiring adjustment...
10-03-2009, 04:10 PM
#1
Slight wiring adjustment... Question...
This is the wiring chart I found that is closest to what I was thinking about doing, but with a slight adjustment. Could the Fuel Pressure Safety Switch be moved to the ground side of the two solenoids? The reason for doing this is that I was going to run the solenoids' grounds to the cylinder head, and since the fuel safety switch is right there, not put it in between.
This is the wiring chart I found that is closest to what I was thinking about doing, but with a slight adjustment. Could the Fuel Pressure Safety Switch be moved to the ground side of the two solenoids? The reason for doing this is that I was going to run the solenoids' grounds to the cylinder head, and since the fuel safety switch is right there, not put it in between.
10-03-2009, 04:33 PM
#2
No. Problem is that the fuel pressure switch needs to be on the low current side of the relay. Not on the high current circuit with the relays.
Now if you find out how many amps the fuel pressure switch is rated for. If it is more than the draw of your solenoids then you can but still isn't favorable. I am sure they aren't rated for 30-40 amps but it is possible.
Now if you find out how many amps the fuel pressure switch is rated for. If it is more than the draw of your solenoids then you can but still isn't favorable. I am sure they aren't rated for 30-40 amps but it is possible.
10-04-2009, 08:36 AM
#3
Do yourself a favor, and ditch that fuel pressure switch completely. Those POS never work right, just the vibration from the motor 1/2 the time is enough to make them cut on/off.
Put a big enough pump in the car so you don't need to worry about it, and throw that thing in the woods. You can thank me later.
Put a big enough pump in the car so you don't need to worry about it, and throw that thing in the woods. You can thank me later.
10-04-2009, 09:28 AM
#4
I kinda feel the same way but I didn't want to say that and have people freak out. I removed mine on my probe after it gave me allsorts of fits. I just wasn't sure anyone else does such a thing too.
10-04-2009, 11:10 AM
#5
I never even put one of those POS things in. Waste of time, if your tuneup is good and you have an adequate pump, and keep up on your filter maintenance and ckeck/clean your noids and jets on a regular basis, there is absolutely no need for one of those things.
The only people that are going to tell you to run a FPSS are the same people that tell you spraying 250 thru a single nozzle into the intake is ok., and that you can spray 300 with pump gas and have no problems, same people that think a standalone is a waste of time, and they're the same people that have never heard of flowing a fuel system.
The only people that are going to tell you to run a FPSS are the same people that tell you spraying 250 thru a single nozzle into the intake is ok., and that you can spray 300 with pump gas and have no problems, same people that think a standalone is a waste of time, and they're the same people that have never heard of flowing a fuel system.
10-04-2009, 11:48 AM
#6
I think what you are saying is that fpss is for the company to cover there a$$ and for ignortant people who havn't hooked up a nitrous kit before? Like I said my experiance years ago was the same but I didn't know if it was the norm.
I am also glad because I wasn't planning on running one this week at the track.
I am also glad because I wasn't planning on running one this week at the track.
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10-04-2009, 01:44 PM
#8
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May be wrong, But I hooked all my switched to the ground side of the realy. it goes from ground to the WOT switch, to the fuel safety switch, to the MSD Window switch then to the soliniod. I ran the arming switch(12+) to the relay. It works
10-04-2009, 02:05 PM
#9
I don't see anything wrong with it.
10-04-2009, 05:52 PM
#10
I know there are alot of mixed opionions on the FPSS however I use a fuel pressure safety switch on alot of installs I do. If you understand how to set them they are no problem at all. Problem is alot of people do not get them set right. The fuel pressure safety switch serves a great purpose. Its not some thing you have to have so its up to you.
See on these cars when a fuel pump goes out it may not stop all together. Some times they will supply enough fuel to keep the car running while only pumping at half pressure.
The fuel pressure safety switch is there to catch a failing fuel pump or cloged fuel filter.
I have seen some really old fpss floating around to where they were so used the set screw was loose and seemed like it may move changing the set pressure. Alittle trick for these is to put a dab of silicone on top of the set screw to keep it from moving.
Once you get these things set right they are reliable and serve there purpose.
Personally I would keep it on the low amp side which is the ground just like in the drawing.
Dave
See on these cars when a fuel pump goes out it may not stop all together. Some times they will supply enough fuel to keep the car running while only pumping at half pressure.
The fuel pressure safety switch is there to catch a failing fuel pump or cloged fuel filter.
I have seen some really old fpss floating around to where they were so used the set screw was loose and seemed like it may move changing the set pressure. Alittle trick for these is to put a dab of silicone on top of the set screw to keep it from moving.
Once you get these things set right they are reliable and serve there purpose.
Personally I would keep it on the low amp side which is the ground just like in the drawing.
Dave
10-04-2009, 06:11 PM
#11
Let me add this..
To adjust the fuel pressure safety switch there are a few ways in doing so.
1. With air pressure and a air regulater. You would need some fittings to adapt to where you can screw the fpss in and adapt the air hose. You can simply set the air pressure to the psi you want and with an ohm meter you would check to see when the switch is open or closed.
2. Take and crank the car with the FPSS installed. Using a ohm meter turn the set screw on the fpss until it breaks contact. Then turn it back till it has contact. Then do about 3/4 of a turn more to give a window for pressure drop.
3. If you do not have an ohm meter you can set them by free flowing the system into a can and turning the set screw. In order to do this make sure there is no nitrous in the system. Crank the car with the fpss installed. Hold the fuel line that feed the nozzle or plate from the solenoid into a can. Then have someone activate the system. Remember turn the screw right to increase pressure and left to decrease pressure. Turn the screw until the solenoid starts to chatter breaking up the fuel flow. Then turn it slowly the other way until the fuel flow is steady again and the fuel solenoid is not chatering. Then do 3/4 of a turn more to leave a window for pressure drop.
Keep in mind that the fpss is mearly there to shut the system down incase of fuel pump failure. That is its only purpose.
You want to leave an area on the setting to allow the car to fluctuate in pressure up to atleast 5 maybe a tad more. It is normal for a cars fuel pressure to drop a tad when the fuel solenoid first opens. You need a window in the setting to allow this.
Now if the car is having a significant drop in fuel pressure the fpss is doing its job and you need to see what is going on with the fuel system.
I have had people call me telling me the fpss was killing there system and people were telling them just to take it off. After checking with them to make sure it was set right I talk them into putting a fuel gauge on the car and low and behold the switch was doing its job. They were having fuel delivery issues and if they would have listen to there buddys they may have been putting a motor in there car.
Dave
To adjust the fuel pressure safety switch there are a few ways in doing so.
1. With air pressure and a air regulater. You would need some fittings to adapt to where you can screw the fpss in and adapt the air hose. You can simply set the air pressure to the psi you want and with an ohm meter you would check to see when the switch is open or closed.
2. Take and crank the car with the FPSS installed. Using a ohm meter turn the set screw on the fpss until it breaks contact. Then turn it back till it has contact. Then do about 3/4 of a turn more to give a window for pressure drop.
3. If you do not have an ohm meter you can set them by free flowing the system into a can and turning the set screw. In order to do this make sure there is no nitrous in the system. Crank the car with the fpss installed. Hold the fuel line that feed the nozzle or plate from the solenoid into a can. Then have someone activate the system. Remember turn the screw right to increase pressure and left to decrease pressure. Turn the screw until the solenoid starts to chatter breaking up the fuel flow. Then turn it slowly the other way until the fuel flow is steady again and the fuel solenoid is not chatering. Then do 3/4 of a turn more to leave a window for pressure drop.
Keep in mind that the fpss is mearly there to shut the system down incase of fuel pump failure. That is its only purpose.
You want to leave an area on the setting to allow the car to fluctuate in pressure up to atleast 5 maybe a tad more. It is normal for a cars fuel pressure to drop a tad when the fuel solenoid first opens. You need a window in the setting to allow this.
Now if the car is having a significant drop in fuel pressure the fpss is doing its job and you need to see what is going on with the fuel system.
I have had people call me telling me the fpss was killing there system and people were telling them just to take it off. After checking with them to make sure it was set right I talk them into putting a fuel gauge on the car and low and behold the switch was doing its job. They were having fuel delivery issues and if they would have listen to there buddys they may have been putting a motor in there car.
Dave