I have a TNT dual nozzel kit with full thottle, digital window, and fps switches. I am in the process of testing my system. The solenoids pulse upon activation. So I started bypassing things to find the problem. The fpss was the first thing I checked. When I bypassed it, it fired normal. I have checked the pressure setting with a test light. The fuel pressure is at 38/39 at idle (with the vac line on). I bought a new fpss and have the same problem. I am testing with the lines disconnected from the foggers and the foggers capped with vac caps. I have set the activation points on the MSD digital window to 1800-on 2400-off for testing. The fpss is right behind the fuel solenoid. Any ideas.

 

Weak fuel pump? Sounds like your fpss is doing its job.

 

I have a Walbro 255 intank. It has about 17,000 miles on it.

 

I have seen Walbro's fail only after 2000 miles. I would put a fuel pressure gauge on the fuel rail and take it for a spin. Sounds like its losing pressure and tripping the fpss.

 

Could it be because for testing I have the fuel lines dumping into a bottle and there is no jet to keep any kind of pressure?

 

I have a fuel pressure gauge in the A pillar. Fuel pressure is fine out on the road.

 

Ok, I am an idiot. It was because I did not have the jets in the lines. I put the jets on the end of the lines and it sprays just fine.

 

Good catch.