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Technical => Engine Tech Forum => Topic started by: Chris E. on February 07, 2007, 09:48:12 PM

Title: Fuel Pressure
Post by: Chris E. on February 07, 2007, 09:48:12 PM: Dumb question----If dual carbs are supposed to opperate at 3 to 3.5 psi, but the pressure going to them is 4.5 to 5 psi, will this cause any problems during engine opperation? Flooding?
Title: Fuel Pressure
Post by: Chris on February 07, 2007, 10:07:04 PM: pressure is to be set at idle as I was told

so you may be ok, but once your engine is idling you can go adjust your fuel pressure
Title: Fuel Pressure
Post by: Bruce on February 08, 2007, 04:53:13 AM: Quote
... the pressure going to them is 4.5 to 5 psi, will this cause any problems during engine opperation? Flooding?
Yep, yep.
Title: Fuel Pressure
Post by: Cameron on February 08, 2007, 08:22:26 AM: What kind of fuel pump are you using?
Title: Fuel Pressure
Post by: Chris E. on February 08, 2007, 09:28:12 AM: Quote
What kind of fuel pump are you using?
Fuel-flo rotary
Title: Fuel Pressure
Post by: Cameron on February 09, 2007, 08:17:08 AM: You can try running the motor with slightly higher fuel pressure, but you're getting into iffy territory. If the electric fuel pump is over running the stock needles and seats, you have three solutions.

1) Open your fuel pump, and play with the internal regulator. This may be a trial and error kind of thing, which will waste lots of time and effort, and may solve nothing. Also, may void your warranty.

2) Get a pressure regulator, and place it in line somewhere. Get quality stuff, don't waste your money on a cheap regulators, as they act more like volume restrictors.

3) Replace the original needles and seats with after market \"ball type\" needles and seats. I prefer this idea, as it leaves the pressure on the high side. Also gives you a reason to open the carbs and inspect the floats.

http://www.geneberg.com/cat.php?cPath=8_27...de6433ea152eee1 (http://www.geneberg.com/cat.php?cPath=8_270&osCsid=da73ec35c85da6f36de6433ea152eee1)
Title: Fuel Pressure
Post by: James Buchan on February 09, 2007, 11:48:58 AM: Thos fuel flo pumps are internally regulated to 3-3.5PSI
Title: Fuel Pressure
Post by: Chris E. on February 24, 2007, 09:00:45 AM: Installed a new Holley 1-4 psi fuel pressure regulator and dialed it in at 3.25psi. Every time I start the car, my fuel pressure guage (new)reads something different. Sometimes 2psi or 3.5psi. What could be the problem? :wacko:
Title: Fuel Pressure
Post by: Stephan Schmidt on February 24, 2007, 12:25:37 PM: Stock fuel pumps work great and are cheap. If a stock fuel pump can power an IDA cal-looker into the 12 second 1/4 mile, then there really isn't a need for an unreliable aftermarket unit.

Just my opinion. It would save you a bit of a hassle Chris.

Stephan
Title: Fuel Pressure
Post by: Bruce on February 24, 2007, 04:29:31 PM: Quote
Installed a new Holley 1-4 psi fuel pressure regulator and dialed it in at 3.25psi. Every time I start the car, my fuel pressure guage (new)reads something different. Sometimes 2psi or 3.5psi. What could be the problem?
How does it run? If it runs fine, you are done. You aren't required to have 3 psi.
Title: Fuel Pressure
Post by: Chris E. on February 24, 2007, 06:00:45 PM: Quote
How does it run? If it runs fine, you are done. You aren't required to have 3 psi.

Runs great, now that I've synched up the carbs.
Thanks Bruce.