Just bought an 85 GMC Jimmy full size blazer with a 305 motor carburated. Had blown mufflers, replaced them with 24" glass packs. Replaced cap, rotor, coil, wires and plugs. Here is what it WAS doing.........Hesitation/Bog on initial ecceleration from stop. Misfire when you let off the gas from exaust while goin down the road at steady speed. It would flood itself out if i let it warm up in driveway. If I took off with cold engine, no bog but much louder and frequent miss fire. Once warm, little to no miss fire. Ecceleration was ok and otherwise it ran pretty good. Everyone told me to junk the quadrajet that was on it and get an edlebrock, so i did. Today i fired it up and guess what, the miss fire is MUCH worse. The hesitation/bog when warm is completely gone, BUT, the missfire is louder and more frequent. Mostly when I just let off the gas I get a good pop out the exaust. Any advice as an easy quick fix or something simple to check for would be great. I am gonna check the plugs again and maybe get a hotter plug cuz the ones i got are cheap and the old ones were black. The more I read on these early 80's 305's the the worse it looks for my pocket book. Mostly cam trouble from what I am reading. If someone could also tell me how to get rid off all these vaccum lines and sensers without creating an elusive vaccum leak that would be great too. Thanks, Vince
- posted
20 years ago