FPR Creating blm Problem please help.

S

Slp223

New Member
Joined
May 1, 2012
My Bml were at 150 so i started replacing vacuum lines one by one. With all the hoses off the vacuum block and the lines all capped. My blms get to to 136,137,138 area, I connected the PVC line blm stayed to same. then I connected to map line again BLM the same. I connect the FPR line and BLM shoot to 150. When I pull the line back off the FPR they come back down in the high 130s.

The car is 100% stock.
TPS is .40 at idle
IAC is 17 at idle.
FP line off at 39-40
FP line on at 30.
 
Wouldn't you want around 37 psi with line on? Maybe that's causing lean, low fuel pressure? Is the fpr adjustable??
 
fp is not adjustable. Everything on the car is stock. If I buy an AFPR an increase my FP should it solve this problem?
 
Has this condition changed from past? My BLM at idle is about 150 also. I think the reason it goes up with fuel pressure regulator hose blocked off is the vacuum pulls the fuel pressure down (vacuum to regulator - supposed to) and the computer compensates by running duty cycle up. I've attributed my high BLM #s (at idle) to the breathers on rocker arm (commonly called valve) covers. If #s have recently changed did you add breathers that allow unmetered air into the engine? I think you are ok unless these readings changed without any other changes.
 
looked at your fp readings. Don't remember stock fuel pressure, but if you are pulling 9 psi of fuel pressure out, suspect you have good vacuum and no leaks.
 
Front Mount said:
Has this condition changed from past? My BLM at idle is about 150 also. I think the reason it goes up with fuel pressure regulator hose blocked off is the vacuum pulls the fuel pressure down (vacuum to regulator - supposed to) and the computer compensates by running duty cycle up. I've attributed my high BLM #s (at idle) to the breathers on rocker arm (commonly called valve) covers. If #s have recently changed did you add breathers that allow unmetered air into the engine? I think you are ok unless these readings changed without any other changes.
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Breathers on the valve covers will NOT change BLM numbers. Unmetered air getting into the crankcase isn't shortcutting the MAF. To do that it would somehow have to find its way into the throttle body. Aint happening.

I'm thinking a faulty FPR in this case. Symptoms certainly point in that direction anyway.
 
An AFPR ? Chip, yes. In this day and age of modern adjustable chips, and AFPR isn't really even needed any longer. A good 237 regulator will yield the desired base fuel pressure, and any tweaks can be done in the chip. I haven't touched my fuel pressure in over a decade. If I hadn't gotten rid of my 237's they'd be going right back in and the AFPR would be coming off.
 
TurboDave said:
An AFPR ? Chip, yes. In this day and age of modern adjustable chips, and AFPR isn't really even needed any longer. A good 237 regulator will yield the desired base fuel pressure, and any tweaks can be done in the chip. I haven't touched my fuel pressure in over a decade. If I hadn't gotten rid of my 237's they'd be going right back in and the AFPR would be coming off.
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Ok, so are you talking about all the TT and Bailey chips that allow adjustability?? I could see where with a SD2 chip could easily compensate with a stock regulator...I guess all the adj. chips I've used have been timing and WOT fueling...
 
3.8L V-8 eater said:
Ok, so are you talking about all the TT and Bailey chips that allow adjustability?? I could see where with a SD2 chip could easily compensate with a stock regulator...I guess all the adj. chips I've used have been timing and WOT fueling...
Click to expand...

Yes, I'm referring to TT or Bailey chips because that's what predominates the market. Just look at ANY thread where someone is asking advice on a chip, What does EVERY single replay recommend? And there's more than just WOT fuel adjustability in them. All the Bailey chips have BLM compensation (base fuel curve) and WOT tuning built in. I'm quite sure most if not all of the TT chips have more than just WOT fuel tuning in them, not just the SD chips.
 
Yes, you can add or subtract from the "base". That would allow the use of the 237 regulator and fine tune the fueling. I will probably experiment with the 237 too. Not feeling the Accufab.
 
TurboDave said:
Yes, I'm referring to TT or Bailey chips because that's what predominates the market. Just look at ANY thread where someone is asking advice on a chip, What does EVERY single replay recommend? And there's more than just WOT fuel adjustability in them. All the Bailey chips have BLM compensation (base fuel curve) and WOT tuning built in. I'm quite sure most if not all of the TT chips have more than just WOT fuel tuning in them, not just the SD chips.
Click to expand...
I knew there were more adjustments just speaking for what I have used mostly...You bring up a good point that I never really thought about....I really always looked at it as get a AFPR set it per the chip makers recommendation then if additional tweaks are needed then readjust it....Doing it through the chip isn't talked about much and everyone still recommends regulators to newbies with stock set ups...
Thanks for the info Dave
 
Before doing any tuning or chip adjustment, I would say get your fuel pressure up to the 37 psi factory setting with adjustable fpr and see if it's still running lean.
 
buickGN3:16 said:
i have blm @ 147 all the time, did all vac lines, no change, sick of looking for the problem!
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Your best friend,in my opinion, when it comes to finding/fixing vacuum leaks is a MityVac vacuum pump and/or Smoke machine. I had bought band new vacuum lines and connectors that had leaks and I wouldn't know it if I didn't check them with a MityVac. Smoke machines are expensive but if I remember correctly theirs a post in the "How To" section on how to make one. Hope this helps, Kyle
 
buddy said:
Before doing any tuning or chip adjustment, I would say get your fuel pressure up to the 37 psi factory setting with adjustable fpr and see if it's still running lean.
Click to expand...
BTW probably not related but i would try to get the tps at 42 key on , 44 idle, you will have to adjust the iac after.
 
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