Fuel Pressure Problem, Need Help!

[BLACK87GN]

my fuel pressure won't go any lower than 42 psi at idle, even with the adjusting screw all the way out and vacuum line on or off. but when the car is driven for about a half hour or more the fuel pressure will drop about 5 psi at idle. anyone else ever have this problem? the regulator is accufab only a couple months old and checked vacuum to reg and its 15". could the return line be blocked? i assume the line going into the reg is the supply and the other is return? sorry for the long post, i'm new to this. any help i can get will be greatly appreciated!

 

[NickSJ]

Return Line or maybe...Injectors? FPR?

I had a similar problem - with the Accufab I would adjust it, then go out and romp on it a few times, then check gauge again which would now read 5psi higher or lower. Tried a new gauge too, checked return line flexible areas, blew it out, etc. because it seemed like a return line issue. I bought all this stuff from summit to replace it, 20' of braided line and AN connectors - cost me like $120.

I was using 36 lb injectors I think (green stripe), and replaced with MSD 50s in preparation for the TE-44. Problem went away, completely. Don't know how injectors could have caused this problem, but nothing else had changed. Anyway, I now have all this neat braided line and fittings that I never installed.

BTW, that was about 8k miles ago. Last week, I tried to adjust the Accufab for the first time in months, and the screw stripped. Had to drill out the top for a 5/16-24 bolt instead. Who knows, maybe my problem was the early signs of stripping bolt...

Good luck,

 

[BLACK87GN]

fuel pressure

the injectors in my car are delphi 33# from ATR. i wonder if the injectors could be the problem? thanks for the reply NickSJ. anyone else ever have this problem?

 

[trbodon21]

try this link.
http://www.gnttype.org/techarea/fuelsystem/fpsys_check.html

 

[BLACK87GN]

fuel pressure

thanks for the link trbodon21. can you or anyone else tell me which fuel line is the return? is it the one that goes into the regulator or the one in the fuel rail?

 

[trbodon21]

The return is the line connected to the bottom of the regulator.

 

[klrv6]

Just a thought

My cheap autozone FP gauge holds the pressure until you bleed it with the little clear hose. I have the accufab unit and thought it was not adjusting until, I found I need to drain the pressure with the engine off (DO NOT DRAIN WHILE THE KEY IS ON!!!) I would raise it no problem but it would not release any on it's own. Just a thought