Can't lower fuel pressure below 46 pSi
#1
Can't lower fuel pressure below 46 pSi
So my ECU is tuned to 43.5. Stock pressure. Noticed it was actually about 50 psi! ....started adjusting the little screw on the AFPR and couldn't get it to go below 46. Now LOTS of guys running 45 or 46, so I'm not against letting it be and re-tuning for it, however I'm a little concerned that I CAN'T lower it if I wanted to.
Details: BBK AFPR has been used at 43.5 for years, and without removing from the rails, is now on my new 383. I do have a new Racetronix 255 pump, but I can't see that pushing it THAT high that I can't go any lower. LOTS of guys running 255's and I've never heard of this issue.
Thoughts? Not really worried....but it's nagging at me
Details: BBK AFPR has been used at 43.5 for years, and without removing from the rails, is now on my new 383. I do have a new Racetronix 255 pump, but I can't see that pushing it THAT high that I can't go any lower. LOTS of guys running 255's and I've never heard of this issue.
Thoughts? Not really worried....but it's nagging at me
#3
Re: Can't lower fuel pressure below 46 pSi
Yes, the car was running and vacuum was disconnected. Started at 50, dropped to 46. ....with vacuum, at idle it's about 38/39. ....and I adjusted the fuel accordingly in the tune to 46psi (was at 43.5) How much of a difference will it make, I don't know. Is 2.5pSi insignificant, or HUGE!? I don't know, but just to be safe I adjusted the #per hour/actual pressure in the tune.
My issue is more WHY can I not drop it lower than 46?
My issue is more WHY can I not drop it lower than 46?
Last edited by Abubaca; 12-23-2016 at 07:40 AM.
#5
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Car: 1989-92 FORMULA350 305 92 Hawkclone
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Re: Can't lower fuel pressure below 46 pSi
Sure the psi gauge is working properly?
#6
Re: Can't lower fuel pressure below 46 pSi
That's a odd one that you can't lower it down any more.
Sure the psi gauge is working properly?
#7
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Car: check
Engine: check
Transmission: check
Re: Can't lower fuel pressure below 46 pSi
The return line may be kinked or dented. Also, back at the tank to frame lines, double check that the return line from the frame goes to the tanks return. Not the tanks vent line (CCP vent).
RBob.
RBob.
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#9
Re: Can't lower fuel pressure below 46 pSi
Pretty sure I hooked up the lines properly, but of course, I'll have to check to be sure. ....as for the line being kinked, or possible something restricting inside....obviously it's possible, but it worked just fine when it came off the road. ....but yes, I understand anything is certainly possible. I'm gonna move forward with tuning, however I'm also gonna dig into this a little. If for no other reason than piece of mind.
Thanks guys
Thanks guys