The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - Project Underfunded / next phase

68GMCCustom · 07-08-2012, 08:58 PM

OK guys....need some help...or maybe I should have just left a carb on it.

Now that my pedal works I took it straight to the gas station as the tank was empty, and then straight back home as it was not only running bad but my power brakes weren't working. I've spent time looking for leaks and even did some hose replacement and still the same issue. It idles like crap, smokes, and has roughly 7" of vacuum.

This booster/vacuum canister setup was unchanged from when it was carb'd, had decent vacuum, and stopped on a dime. Upgraded hoses with no change. I'm beginning to think my bad vacuum is the result of the state of tune...rather then the other way around. Seems to be way rich and I see more timing then I had in it carb'd. Beginning to think I just need to send the ecm back...again.

best vacuum I can get is on idle down after reving and is 15" at best.

canister and pcv routing

07-08-2012, 08:58 PM	#125
68GMCCustom Truck and auto performance nut Join Date: Feb 2007 Location: McKinney,Texas Posts: 3,848	Re: Project Underfunded / next phase - LSx carb'd to LSx efi OK guys....need some help...or maybe I should have just left a carb on it. Now that my pedal works I took it straight to the gas station as the tank was empty, and then straight back home as it was not only running bad but my power brakes weren't working. I've spent time looking for leaks and even did some hose replacement and still the same issue. It idles like crap, smokes, and has roughly 7" of vacuum. This booster/vacuum canister setup was unchanged from when it was carb'd, had decent vacuum, and stopped on a dime. Upgraded hoses with no change. I'm beginning to think my bad vacuum is the result of the state of tune...rather then the other way around. Seems to be way rich and I see more timing then I had in it carb'd. Beginning to think I just need to send the ecm back...again. best vacuum I can get is on idle down after reving and is 15" at best. canister and pcv routing __________________ Kurt - '68 GMC short step - NIB '09 LY6 6.0L crate motor w/mods, NIB '12 crate 4L85e w/billet 3k stall Circle D, 3.73 posi 12 bolt, DynaTech f-swap headers, 3/4 drop, handling mods, etc. - my toy '72 Chevy LWB C-10 Highlander - 350/350 ps/pb/tilt/ac - not original but close '06 Chevy TrailBlazerSS - LS2/4L70e - little black hot rod SUV - my DD '18 Kia Sorento - wife's econo-driver '95 Chevy S10 - reg cab shortbed, LS, 4.3, auto... my '68's powertrain and chassis build -links broken A surprise phase - carb to efi -links broken Last edited by 68GMCCustom; 07-08-2012 at 09:05 PM.