Fuel pressure constantly changing

I got a lot of my issues fixed but I seem to have yet another one. I installed a different bypass fitting because the instructions said that when you have a Walbro 255, you need to run a 2.5 mm fittings. Now at idle my fuel pressure gauge needle is very jumpy. It jumps only a PSI or two, but it fluctuates constantly until a very little throttle is applied, and then it even outs.

The major problem is this. Yesterday, I got my fuel pressure set at 36 psi. It ran and drove amazing! Today I started my car and it was stumbling. I floored it to see a ton of black smoke come out the tail pipe. I look under the hood and my fuel pressure is reading 50 psi. :wtf: I didn’t change anything, why would it have suddenly gone up? So I readjust it to 36 psi. I take a drive to get fill my tank. Fill it up and start it up. I decided to take another glance under the hood and now I’m at 43 psi. :wtf::wtf: I drove it around for a little while, and it seemed to stay steady at 43 psi.

I’m unsure if I’m running to large of a bypass fitting, or if this is some unrelated problem to what I’ve done with the bypass fitting.

Basically I’m looking for some things to check or ideas as to what others might think this.

fuel regulator?

Its a Synapse fuel pressure regulator. Walbro 255 fuel pump.

chek if the regulator is good

I’ll have to look into how to do that. I have a feeling it might need a rebuild. Bummer.

Get an Aeromotive and make some lines.

I called Synapse and they said I most likely don’t have enough preload tension on the internal spring. I’m going to try and adjust that tomorrow.