maksik7

Hey guys,

I just got my car running again, but I am having problems with the engine. It's a stock LB9 engine with an Edelbrock performer and a non-CC Q-jet on top. It idles great but it has these probems. First it stumbles a bit when I rev it (goes away mostly when warmed up), then when I take it out for a ride the engine has very little power. Also, when I let go of the gas pedal, the engine backfires (lots of small backfires) on deacceleration.

The thing is, the carb worked flawlessly when it was on my old 350, its only after I swapped the intake and carb onto the 305 that the problems started. I couldn't get any help so far, so I would really appreciate it if somebody here told me what's wrong and how to fix it.

I suspect it's just pumping way too much fuel for the little 305, and that the solution is very simple.

-Max

Vader

Your symptoms actually sound like a lean condition, not rich. In either case, a look into the carb and adjustments would be in order.

maksik7

Could anybody eleaborate on what Vader said? I know that the carb needs to be adjusted, but exactly how would I go about doing that? Do I need to buy any new parts, or is just adjusting the exhisting parts? I would prefer to do it myslef for financial reasons, but it that doesn't work out, do you think I could just take the carb to a shop, give them my specs, and have them tune it?

-Max

jimmy_mac

I didn't notice if you said you also swapped out the stock cc distributor. I assume you have but just wanted to check.

maksik7

No, this is the original non-CC carb that was on the car when the 350 was iin it. does anybody else have ideas what's my problem.

-Max

RB83L69

So what about the distributor? Is it the car's computer one or not?

If it is the car's OE one, then you need to get it out of there and put a mechanical/vacuum controlled one in.

maksik7

The car has no computer. The distributor was and still is a non-CC vacuum advance type. It is not an OE unit.

-Max

jimmy_mac

Are all the vacuum ports either hooked up or plugged. Especialy the big one in back for the brakes. I forget to put that one back on from time to time. It runs similiar to what you are describing when that happens.

Your really shouldn't have a whole lot of adjustments to make for a 350 to 305 swap for just normal idleing and driving. Sounds like something is amis. Like a vacuum leak. I'm chasing one of those right now on another car. At least I think I am.

pheonix305

someone correct me if im wrong but to tune a carb you either get bigger or smaller(wich ever the case maybe) jets or different metering rods. you can also ajust the float level but that dosent do anything for air fuel mixture.