so i finally got my 98 civic non vtech 1.6 road worthy after lots of heartache. after the first day of full driving i shut off for about 30 min and the car wouldnt start back up. i could tell it wasn't getting the fuel so i let the the pump prime for a couple of minutes and finally it started. got it home and it did the same thing. talk to some buddies and did some research and figured, ok its got to be the filter or regulator. changed both started right up. an hour later same thing happened. got 4 regulators from the junk yard, figured must have been a bad one. same thing happening with all of them. but what i have noticed is when i let the pressure leak out of the FPR and bolt it back down, the car will start right up every time. let it sit, it wont start, crack the FPR loose tighten back up it starts. car runs beautifuly except for this. any input is appreciated

 

Might not be returning to the tank at all...try blowing in your return line and see if its clear.

 

same issue. blew the return line out and no change. still bleeds down in less than 10 minutes. possibly injector leaking down? i dont know

 

If you tried 4 different stock regulators and they are all leaking down, you have a fuel leak somewhere.

You need to do some more advanced troubleshooting...this just isnt enough info to go on really to figure out the issue.

Is it too rich or too lean when it wont start?

 

Holding pressure at the rail (after keying off) is dependant on two check valves sealing 100%: 1) fuel pump outlet 2) regulator. If you've tried 4 different regulators and you continue to lose pressure, I'd check the pump outlet.
Or
You could install an in-line check valve between the filter & rail...?

 

@xenocron id imagine its to lean because there is not fuel even making the engine sputter when attempting to start.also when i take off the FPR hardly any fuel comes out, but you can hear atmospheric pressure pushing the rail clear of fuel allowing it to fill after the key on. what other information would you need to know to make a better diagnosis?
@scmil i would consider the check valve on the supply side of the rail but it seems to me that when after the FPR is removed and replaced the pump is more than enough to make fuel come back to the rail. why would it not do this simply after key on rather than only after FPR is r+i'd?

is it possible that the vacuum side of the FPR is not getting the continued pressure it needs when key off after running to allow all fuel and air from the rail to pass through and clear the rail?

 

Ya kinda lost me there, but if I understand your follow-up correctly; the check valve on the outlet of the pump has nothing to do with the pumps output. Give it 12 volts, it still gives you 100%, so of course fuel will come back up to the rail. You're just not able to hold it there.

So if we boil this down to the basics, you could be losing pressure through:
1) injectors
2) regulator
3) fuel pump check valve

I'd say you've thoroughly ruled out #2 (unless you have the absolute worst luck in the world). Unless there's a puddle of gas under your car, you have two more checks to go.

 

sometimes with this car i feel like i have the worst luck anyone could ever have. as far as the solenoid side of the injectors i dont have a cel, is there a way to know if the mechanical side of the injector is leaking down? i was saying, doesnt pump supply supersede the check valve as far as if the pump can push pressure back up,the check valve is made null?
*i do not mean to come off as presumptuous its just how i type*
is the check valve for the pump built in to the pump? ive been doing everthing i can to not buy a fuel pump for this, but as it seems to me that is the only logical next step

 

pure f*****g magic but the car just started holding prime and is running beautifuly. i didnt do anything it just began starting first turn of the key. thanks for the help guys