carb problem??? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

pimperout · 10-15-2006, 03:00 AM

im running a 350 with a 4 barrel rochester (i dont know all this fancy talk of bbl's and such im kinda new to the whole engine thing) my engine since i bought it alway ran kinda rough and it sounded really mean and ran nicely but my gas milage was absolutly terrible and it didnt seem to have enogh power so i had a friend time it for me, it was about 15 degrees off so we fixed that and it runs real nice now till you step on the gas then it kinda sputters a bit then returns to normal once you let the pedal out about halfway, i just thought it was flooding so i didnt really think much of it till i bought a parts truck that the owner said did not run it just toook a fuel line cleaning and it run quite nicly soon i noticed when i floored it in that truck it made a satisfying roaring sound when the 4 barrel kicked in and my good trucks did not, so i dont know what to do with carbs or anything i would just like to get some pointers on how to adjust fuel/air intakes or various other adjustments to make it run better.

Sweet72 · 10-15-2006, 04:32 PM

Could be your primary accelerator pump is not working correctly which would require disassembly of the carb. The accelerator pump gives a metered shot of fuel into the intake when the accelerator is depressed. It definitely sounds fuel related. I'd install a rebuild kit, but if you're not mechanically savvy leave it to a pro.

pimperout · 10-15-2006, 10:18 PM

alritty thanks

10-15-2006, 03:00 AM	#1
pimperout Registered User Join Date: Sep 2006 Location: Bow Island, AB, Canada Posts: 166	carb problem??? im running a 350 with a 4 barrel rochester (i dont know all this fancy talk of bbl's and such im kinda new to the whole engine thing) my engine since i bought it alway ran kinda rough and it sounded really mean and ran nicely but my gas milage was absolutly terrible and it didnt seem to have enogh power so i had a friend time it for me, it was about 15 degrees off so we fixed that and it runs real nice now till you step on the gas then it kinda sputters a bit then returns to normal once you let the pedal out about halfway, i just thought it was flooding so i didnt really think much of it till i bought a parts truck that the owner said did not run it just toook a fuel line cleaning and it run quite nicly soon i noticed when i floored it in that truck it made a satisfying roaring sound when the 4 barrel kicked in and my good trucks did not, so i dont know what to do with carbs or anything i would just like to get some pointers on how to adjust fuel/air intakes or various other adjustments to make it run better.

10-15-2006, 04:32 PM	#2
Sweet72 Registered User Join Date: Nov 2003 Location: Alexandria, VA Posts: 1,534	Re: carb problem??? Could be your primary accelerator pump is not working correctly which would require disassembly of the carb. The accelerator pump gives a metered shot of fuel into the intake when the accelerator is depressed. It definitely sounds fuel related. I'd install a rebuild kit, but if you're not mechanically savvy leave it to a pro. __________________ '72 GMC SWB C1500 Custom, frame-off in progress. 383 SBC, 9:1CR, Comp Cams XE262H, Scat internal balanced crank, Eagle SIR 6" rods, Keith Black dish pistons, Dart Iron Eagle 72/180 heads, Weiand Stealth intake, Stewart stage I water pump, Holley 4bbl vac sec, TH350 with B&M Shift Improver Kit. 12 bolt positraction.

10-15-2006, 10:18 PM	#3
pimperout Registered User Join Date: Sep 2006 Location: Bow Island, AB, Canada Posts: 166	Re: carb problem??? alritty thanks

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