The car is a 1991 Si Civic. I noticed for a while the car would turn on but it wouldn't crank until the second try. Looked it up on here and the simple fix i found was the fuel pressure regulator. Of course I waited and over the course of a couple weeks it went from the 2nd try, then the 3rd try, then the 4th try, letting it prime etc... So i finally ordered the regulator. I drove it a couple days ago and i must have turned the key almost 20 times and it finally fired up and i managed to get it back to my driveway. The regulator arrives, i do the swap, and it doesn't start at all. For Ss and Gs I put the old regulator back in and it still doesnt start at all (no cranking). I stuck the new regulator back in since I already have it. When I turn the car on (not starting it) I can hear the relay click on, the CEL turns on, and I can hear the fuel pump whirr. Then I hear the relay click off, the light turns off, and the fuel pump stops. I checked voltage at the pump with the plug connected to it and it shows me 11V while it's powered.

Some further info:
Back when it only took a couple tries to start it, I would drive it fine and then park it and grocery shop/whatever, and then when I go back to start it agian, it would take a couple tries and when it finally ran it would idle low and almost stall out unless i gave it steady throttle. after about a minute it ran normally

Just before all this happened, my key would spin almost free in the cylinder and not start the car, and I would have to twist it just the right way to get it to start. I found some loose screws right on the back of of it and tightened them it started great every time.

There's a black box under the hood near the battery with fat wires that i believe goes to the starter and I checked voltage there as well, all showed 12V. When I turn the key to actually start the car I hear the click for that as well.

I watched this video and despite the voltage being okay on his fuel pump, the fuel pressure still tested low and he had to replace the pump anyway... but his car also started... my next move is a fuel pressure tester


Any other ideas on this?

 

Found this thread: https://honda-tech.com/forums/tech-m...mp%5D-2961164/

I jumpered the starter and it starts right up no problem. don't have a light for the second test yet, but maybe it is my ignition switch after all

used a multimeter instead of light, looking for ~12V signal. No voltage at all

 

Determined it's the ignition switch after all

https://honda-tech.com/forums/honda-...agram-3354683/

I used these diagrams and pretty much learned how to hot wire it without the key. I found that when I turn the key to the start position there's no voltage on the start position "output" wire, and everything else downstream is fine.