Got my SMC alky working again but spray comes on too early

[VadersV6]

Dont know if anyone saw my thread from a month or so ago, saying my alky stopped working. Turned it out was what I suspected. My pump seized up from the tank being dry and corrosion flakes floating around in there getting sucked in. This kit I bought used...its VERY old but Ive done alot to make it like new. After an hour of flushing over and over and over with penetrant (there was SO much crap in that pump...tons of black ooze coming out) and gradually working the gears loose, I got the motor up and running again and spinning alot faster than it used to. Because the original pressure switch had broken probably a year ago, I had rewired/replumbed everything to run it without the switch. i figured I could live with the lack of a "spray on" light until I got another switch. All worked ok until I ran the tank dry for a few months, and found it was dead. Today I ended up throwing on an old pressure switch I had for my kenne bell boost a pump. Its the later model, metal design of a switch instead of that plastic lever kind. Its a 3.5psi switch, but I figured what could be wrong with that...I just need to know when the line is pressurized. While hitting the prime button, all was ok. "Spray on" light comes on when I hit it, engine bogs and the up-pipe starts to freeze over. But I took it for a spin, nailed it, and the car fell on its face immediately. I stopped and brake torqued the boost up, and found the "spray on" light was kicking on at 4psi instead of the 12-14 it was doing before. I turned the spray point knob up a full turn, and it still turned on at 4psi.
So I guess my question is...is there anything other than the vacuum line going to the controller, that can prematurely trigger the pump to turn on? Im almost positive everything is wired right. I checked all the grounds and they're ok. All the wiring is new and done correctly....in theory.
Ive got the positive and negative running to the pump (black and red). The white is running to the low level switch RCA plug, and from that it goes to a body ground. The green wire is running to the pressure switch, and from there to a body ground. All the plumbing is right, and everything is upgraded to SMC (not SMC alky) quick release fittings and kick ass hosing and everything else is done right. Its the old SMC model with the round bottle, but I made a bracket and mounted it behind the pass. side headlight like that later kits.
Do I need to wire the pressure switch and low level switch in series? I dont see why I would have to, but I dont know how this controller is designed.
I wont be pulling the kit off, so any help I can get to figure this out on my own would be greatly appreciated.

 

[VadersV6]

Ok I just thought of something, but for this to be real, there would have to be a flaw in the design of the controller, or the controller is bad...or the controller was designed this way for some reason I cant think of....Maybe the original kit comes with a check valve on the spray line as a patch, and I just didnt get one with this kit.
I saw alky on the lid of the tank, that was oozing out through the vent hole. That means the tank is pressurizing.
I build boost. Boost pressurizes the line and tank. This triggers my 3.5psi pressure switch which is coming right off the tank. (theres a 4 way block manifold right after the filter...2 holes are plugged. One is the switch and the other is the line). The "spray on" light comes on, and for some reason, triggering that light makes the controller force the pump circuit to fire. This has to be whats happening. I see no other way.

 

[Razor]

You need to send the pump/tank back to Steve and let him replace them. This is one area once it starts going bad.. tick tick tick.. its a matter of time. Dont mess with fueling issues.. being cheap in this dept will 110% guarantee a blown head gasket or worse.

Dont believe me.. you'll remember this post.

Is what it is

 

[VadersV6]

Yeah I take your word for it. In the meantime Im just going to keep the boost low and just spray a little alky, and always keep an eye on O2's and everything. The problem here is obviously a controller design oversight. For one I dont think the feed line should go without a check valve. The idea of boost pressurizing the tank before the spray is triggered isnt great in my mind. Ive got alky oozing out of the vent hole from this. The spray on light switch being triggered by this feed line pressure (from boost bleeding in) shouldnt trigger the controller to turn on power to the pump. A simple check valve will fix all of this. Just have to look around and find one suitable. I know using the SMC style pressure switch will "fix" this, but it wont be right. A check valve should be a must....at least my pea brain says so.

 

[Razor]

Well the switch on the pressure line should be activating at pressures above 30 PSI.. that way the pump is known to be working. If its activating under boost.. you need a new switch or readjust it.

Most fuel pump have a check valve built in, notice how the one in your car retains pressure once you shut the car off.. in your case your pump is toast. But you already knew this..

So a check valve is putting a bandaid on a problem... your trying to get around it.

Put a pressure guage on your pump? Does it go to at least 75 PSI?

Pea Brain would be trusting the system as it is currently.. after all a little knock.. what harm can it do



Leave ya with this, my system doesnt use a check valve. :redface: