FP Regulator bad?
- Thread starter dennisL
- Start date
Anthony P
sharing knowledge with those who care to listen
- Joined
- Jan 24, 2007
I'm not following what that 1/4 x 1/4 compression coupling @Pronto references in post #64 will do for you.
the line from the regulator is 5/16 and transitions to 1/4 at the crossmember. even if you cut off the female end on the regulator line, the OD is 0.31xx and I'm not sure there is enough of a straight section for a reducing coupling, if there is such an animal.
in post #55, those links discuss various methods of replacing that saginaw fitting on the return line. you have to figure out what the threads are on the female connector. I thought I read in the second link they are metric. regular 5/16 tubing uses 1/2-20 threads on the connectors - a 1/2-20 to -6AN adapter does not thread into the female fitting. some have brazed an AN male fitting to the 1/4 line. some note using AN compression fittings. I'm not finding a single fitting to do that.
may have to use 1/4 compression to 1/4 NPT then 1/4 NPT adapter to -6 AN and make a hose section to replace the rubber end of the line from the fpr. instead of researching all the potential ways of doing this and the accompanying fittings and going to a point of no return if you cut off that saginaw fitting, is why I suggested a smaller capacity fuel pump that fits the current engine power level.
that 340 pump is just circulating fuel the engine can't use, not even at WOT. from the flow chart I posted, at fuel pressure = 60, the 340 pump is flowing 50 gal/hr. from the performance chart thumnail image I posted, 50 gal/hr is what a 600 HP gasoline engine needs.
At 18 psi boost, your engine should be making about 330 bHP in stock trim. I add 20 bHP for using a TA49. At 350 to 360 bHP, the fuel requirement is about 31 gal/hr. that Delphi FE0114 pump flows 35 gal/hr. At 360 bHP, your 009 injectors are operating at less than 80% duty cycle.
Also in those theads linked in post 55 are some other members noting a 255 lt/hr pump overwhelmed their stock return line as well. And the ensuing discussion of using two pumps where the second pump comes online via a hobs switch at like 7 psi boost so the return line is not overwhelmed when the engine's fuel requirement is 50 gal/hr.
Try the pipe cleaner idea to confirm there is not some foreign object stuck in the 1/4 line that compressed air cannot dislodge. then I'd spend $50 for that FE0114 pump before I began to cut up the stock fuel lines. no need to recirculate an estimated 15 gal/hr of fuel at WOT and a heck of a lot more when not at WOT. recirculating unused fuel just warms up the gas.
the line from the regulator is 5/16 and transitions to 1/4 at the crossmember. even if you cut off the female end on the regulator line, the OD is 0.31xx and I'm not sure there is enough of a straight section for a reducing coupling, if there is such an animal.
in post #55, those links discuss various methods of replacing that saginaw fitting on the return line. you have to figure out what the threads are on the female connector. I thought I read in the second link they are metric. regular 5/16 tubing uses 1/2-20 threads on the connectors - a 1/2-20 to -6AN adapter does not thread into the female fitting. some have brazed an AN male fitting to the 1/4 line. some note using AN compression fittings. I'm not finding a single fitting to do that.
may have to use 1/4 compression to 1/4 NPT then 1/4 NPT adapter to -6 AN and make a hose section to replace the rubber end of the line from the fpr. instead of researching all the potential ways of doing this and the accompanying fittings and going to a point of no return if you cut off that saginaw fitting, is why I suggested a smaller capacity fuel pump that fits the current engine power level.
that 340 pump is just circulating fuel the engine can't use, not even at WOT. from the flow chart I posted, at fuel pressure = 60, the 340 pump is flowing 50 gal/hr. from the performance chart thumnail image I posted, 50 gal/hr is what a 600 HP gasoline engine needs.
At 18 psi boost, your engine should be making about 330 bHP in stock trim. I add 20 bHP for using a TA49. At 350 to 360 bHP, the fuel requirement is about 31 gal/hr. that Delphi FE0114 pump flows 35 gal/hr. At 360 bHP, your 009 injectors are operating at less than 80% duty cycle.
Also in those theads linked in post 55 are some other members noting a 255 lt/hr pump overwhelmed their stock return line as well. And the ensuing discussion of using two pumps where the second pump comes online via a hobs switch at like 7 psi boost so the return line is not overwhelmed when the engine's fuel requirement is 50 gal/hr.
Try the pipe cleaner idea to confirm there is not some foreign object stuck in the 1/4 line that compressed air cannot dislodge. then I'd spend $50 for that FE0114 pump before I began to cut up the stock fuel lines. no need to recirculate an estimated 15 gal/hr of fuel at WOT and a heck of a lot more when not at WOT. recirculating unused fuel just warms up the gas.
Pronto
Believe nothing you hear and half of what you see.
- Joined
- Dec 9, 2002
This might give you some ideas on the return line if you replace it.
https://turbobuick.com/threads/my-fuel-system-update.396357/
https://turbobuick.com/threads/my-fuel-system-update.396357/
Anthony P
sharing knowledge with those who care to listen
- Joined
- Jan 24, 2007
I wanted to update this thread with the positive results the OP was able to achieve. Dennis sent me a note back in November that he has resolved his fuel pressure problem.
He did order the Delphi FE0114 fuel pump - the Sycloon & Typhoon pump previously discussed, installed it and fuel pressure (vac on) dropped to 34 psi. He's thrilled after all that saga for those years and reports now the car idles better and flat out just runs better. He has a few more fuel changes to make in the chip before he's 100%, but the November weather is not co-operating.
It's a great outcome. AND another example that we all can't use the Walbro 340M (F20000169) or Deutchwerks DW300 on a mostly stock engine (making less than 400bhp and most likely less than 360bhp at 16-18 psi boost with a chip on pump gas) even though the vendors are quite ready and willing to sell us an oversized fuel pump that we may someday grow into.
He did order the Delphi FE0114 fuel pump - the Sycloon & Typhoon pump previously discussed, installed it and fuel pressure (vac on) dropped to 34 psi. He's thrilled after all that saga for those years and reports now the car idles better and flat out just runs better. He has a few more fuel changes to make in the chip before he's 100%, but the November weather is not co-operating.
It's a great outcome. AND another example that we all can't use the Walbro 340M (F20000169) or Deutchwerks DW300 on a mostly stock engine (making less than 400bhp and most likely less than 360bhp at 16-18 psi boost with a chip on pump gas) even though the vendors are quite ready and willing to sell us an oversized fuel pump that we may someday grow into.
If you install a 255 ltr/hr pump and you can't get the idle fuel pressure down where it should be,you have a defective return line. This is an unusual and abnormal occurrence. To lump the 255 ltr/hr pump in with the DW pumps and the Walbro 340 liter/hr pumps is deceptive and misleading. If you install a DW pump or a Walbro 340 liter/hr pump and don't have an idle fuel pressure problem,this is an unusual and abnormal occurrence. One situation point to a defective return line and the other points to a pump that has too much volume for the needs of the engine. Too often,the pump is too big and the person replaces the return line when he just needs a pump with a lower flow rate. In this very rare situation,replacement of the fuel return line would have been the correct solution,but a smaller pump was installed. Go figure.AND another example that we all can't use the Walbro 340M (F20000169) or Deutchwerks DW300 on a mostly stock engine (making less than 400bhp and most likely less than 360bhp at 16-18 psi boost with a chip on pump gas) even though the vendors are quite ready and willing to sell us an oversized fuel pump that we may someday grow into.
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