Xxyyzz Posted January 2, 2013 Share Posted January 2, 2013 What is the proper fuel pressure? The PO put a gauge on the fuel line and it shows 7. Too high/low or good? -Mark Quote Link to comment Share on other sites More sharing options...
LS5 Posted January 2, 2013 Share Posted January 2, 2013 Hey Mark,, happy new year my fellow Canadian friend... if memorey serves me right it should be somewhere between 7-9psi but gonna lean more towards the 7 end.... Darren. Quote Link to comment Share on other sites More sharing options...
Xxyyzz Posted January 2, 2013 Author Share Posted January 2, 2013 Thanks Darren, seems like Im set up pretty well. Happy new year to you as well, I hope 2013it brings you a happy and very healthy year. -Mark Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted January 2, 2013 Share Posted January 2, 2013 on holleys I go 6 1/2-7 psi, I don't like 9, feel it's a little too much Quote Link to comment Share on other sites More sharing options...
Xxyyzz Posted January 3, 2013 Author Share Posted January 3, 2013 its an edelbrock 4bbl (PO installed), I was hoping to save some gas by lowering the fuel pressure. I'm only getting about 9MPG right now. Quote Link to comment Share on other sites More sharing options...
wallaby Posted January 3, 2013 Share Posted January 3, 2013 If only it were that easy. Changing the pressure won't change how much the engine consumes. Your carb is just like a toilet tank: you can turn down the water pressure at your house, but it won't change how much water is used per flush....it just means you have to wait longer for the tank to refill. The idea behind fuel pressure is to be sure you can keep up with demand from the engine when you have the throttle open. If you are trying to pass a truck on the interstate, you don't want the carb to run out of gas halfway through the manuver ( you need to refill the carb as fast as the engine is draining it). turning down the pressure might let the carb run outof fuel and cause surging or even stalling when the engine is under load. The carb will shut off the flow of fuel when it doesn't need it, just like your toilet stops when it gets full. If low pressure was the ticket for good MPG, everyone would want a clogged fuel filter. LOL Quote Link to comment Share on other sites More sharing options...
MCfan Posted January 3, 2013 Share Posted January 3, 2013 its an edelbrock 4bbl (PO installed), I was hoping to save some gas by lowering the fuel pressure. I'm only getting about 9MPG right now. Hmmmm ... might try lowering the "foot" pressure instead, Mark ... Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted January 3, 2013 Share Posted January 3, 2013 Originally Posted By: cardude720 its an edelbrock 4bbl (PO installed), I was hoping to save some gas by lowering the fuel pressure. I'm only getting about 9MPG right now. Hmmmm ... might try lowering the "foot" pressure instead, Mark ... I have to agree I get better than 9mpg with my 454 and a 3.73 gear Quote Link to comment Share on other sites More sharing options...
Xxyyzz Posted January 3, 2013 Author Share Posted January 3, 2013 So true! I'm used to driving my little rice rocket that I can boot around and still get 25 MPG. But going with what wallaby said, I wouldn't want to lower my foot pressure and not have enough gas to pass a truck! My first car was an '01 Crown Vic (FI 4.6L V8) that I got about 12MPG on. So maybe it is just me! What else can I do to improve mileage? -Mark Quote Link to comment Share on other sites More sharing options...
LS5 Posted January 3, 2013 Share Posted January 3, 2013 What else can I do to improve mileage? Besides the obvious joke here of just sitting in it idleing rather than driving it will get you better gas milage... There are some things to try... switch out the holley carb and go with a quadrajet as those 750 double pumpers drink lots.. switching to headers rather than stock manifolds I heard helps with flow to get better milage, actually using the right spark plug for the engine as sometimes the wrong plugs get put in... and make sure the timing is set correctly...bad timing will get that engine struggling and have it idle wrong and drink the gas to try and keep it running.... there is probably more stuff but thats just a couple of idea's.....my other 70 chevelle also had a 454 in it and got 7 miles to the gallon and thats why i dont have it anymore... Darren. Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted January 3, 2013 Share Posted January 3, 2013 those larger diameter tires on your car isn't helping either, I'm guessing you have a 2.73 rear gear, not to mention it's throwing off your speedometer/odometer too (reading less than what you are really doing) going back to a tire that is 26-27 inches in diameter would help some along with it correcting your speedo too Quote Link to comment Share on other sites More sharing options...
MCfan Posted January 3, 2013 Share Posted January 3, 2013 What else can I do to improve mileage? Hey, Mark, there may actually be quite a bit you can do to adjust your current Edelbrock carb to improve mileage (IF you're also willing to modify your driving habits some). You didn't say which model of Edelbrock carb you have, but if it is a Performer or Thunder Series AVS carb, you can order a Carburetor Calibration Kit (about $65) which contains all of the springs, jets and rods you need to make a wide range of adjustments. Also, you can download for free an Owner's Manual from the Edelbrock web site (http://www.edelbrock.com) that contains all of the charts and instructions on how to calibrate your carb for either performance or economy. You already know that power and economy are usually tradeoffs in these older engines so don't set it up for one and expect to get both. Get the manual first and learn which calibration kit you actually need to order. For example, I have a #1806 Thunder AVS carb and the kit that it uses is Catalog # 1840. Although I have the calibration kit and have read the instructions several times, I think I will take mine to a professional engine tuner that can also properly set the timing before messing with the carb. As the instructions say, if you don't have your ignition system (dist, plugs, wires, timing) set up properly, it is futile to try to adjust your carb. If your Edelbrock carb is fairly new, I'm betting you can get better gas mileage with proper calibration/adjustment. Good luck! Quote Link to comment Share on other sites More sharing options...
Xxyyzz Posted January 5, 2013 Author Share Posted January 5, 2013 All really awesome suggestions, thanks guys! My tires are new but I will downsize next time around. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.