hi my name is glenn and i have a 1991 camaro and i converted it from t.b.i. to carborated i have a electronic fuel pump it pumps 5.5-9.5 p.s.i. it is too much for my 600 cfm vacume secondary holly carb i have been killing myself over this problom some one please help i have just purchased a 2.5-4.0 p.s.i. pump would this fix my problem i have tryed holley,spectre,and some off brand and a edelbrock fuel pressure regulators . this is the only remedy i can come up with please help......... :confused:
03-27-2005 07:46 PM
You should install an inline regulator to keep pressure below 7 lbs. Anymore can get by the needle and seat.
04-03-2005 03:19 PM
The tbi system on these cars are a return style system. They have a hard fuel line that feeds fuel and one that returns the un-needed fuel to the tank. If you just stick a convention non- return style regulator, such as the ones that come with say a holley blue pump, you'll burn the stock electric pump up in no time. The regulator that most commonly used for this swap is the Mallory Part No. MAA-4309 regulator. Im using it on my 91 Camaro now and it works great. Using the exsisting metal fuel lines that fed your tbi, you run a line from the 3/8 fuel feed line to one of the 4 ports on the side of the regulator then plumb another from one of those ports to the carb. Then install your fuel pressure gauge line into a third side port and plug the fourth. You then plumb a line from the bottom return line port on the regulator to the smaller 5/16 metal return line thats next to the feed line on the drivers side frame rail. Start your engine and adjust your fuel pressure to what holley recommends for your carb which for street use is 6psi. Check for leaks and away ya go. The stock tbi electric pump will work fine for stock and most mild performance applications up to 325 hp anything above that and it begins to lack the volume to keep up.