zapr

........I had my carb rebuilt and now I notice performance is down. I seem to have to push down further on the gas pedal and the performance just isn't there. Anyone have any ideas? Thanks.......Zapr.

TheBandit

TPI

Sonix

iTrader: (1)

wow, stellar response in the carb forum

stock cc carb right?
why did you have it rebuilt?
who rebuilt it?
motor specs, stock or otherwise?

describe the problem better, not as snappy response? punch it to the floor from a stop and you get a bog? Smells like gas while idling? Punch it and it bogs, then goes? Getting error codes, etc?

zapr

.......Non cc carb. I guess lower throttle response would be a better way to discribe it. No bog. No gas smell. I had the carb rebuilt because it failed the e-test and thought performance would be better. The engine is an lg4 stock. I should also say that the base of the carb was replaced with another one from a carb from the same year as one of the idle mixture screws broke. Everything hooked back up the same. It just doesn't feel as snappy as before.......Zapr.

Sonix

iTrader: (1)

non-cc, so you have a non-cc distributor right?

what is your base timing?
when looking down your primaries, and flicking the throttle, do you see a pump shot?
did you set your lean stop on your power piston? like, did you move it at all from stock? set it to a certain spec?
what primary rods/jets are used? what car did you get the carb off of?

99Hawk120

If he replaced just the carb, and it performed better before, it is probably not timing (unless something else we don't know of has changed).

My guess is if it's a non-CC carb, and he complained about failing emissions to the rebuilder, he might very well have leaned it up. I wonder what jets/rods are in it now...

zapr

.......I replaced the secondary rods with DR's. The primary rods are the same as far as I know. Throttle response is down without opening the secondarys. I had my wife push down on the gas pedal with the car not running while I looked down into the carb. I don't think I'm getting wide open throttle. The secondaries just opened slightly. Should the secondary throttle blades open all the way with the car not running. I'm not referring to the valve doors but the throttle blades themselves. Thanks for the feedback guys......Zapr.

99Hawk120

Yep, but you don't know that the rebuilder didn't change them. Hell, maybe yours were bent and he replaced them with the closest thing he had. You really don't know.

With the choke released, the secondary throttle blades do in fact open all the way with the car off. You'll have to open the air valve to see them, of course. In fact, QJet secondary throttle blades are supposed to open about 10* overcenter to direct the fuel closer to the center of the intake manifold. If the secondary throttle blades are opening, but not opening all the way, then you do have an issue there. If they don't open at all, release the choke and try again.

Vader

How much slack is in the throttle cable?

Is your car a Canadian/Export model? (Non CCC QuadraJet on an '85 isn't stock for Federal cars.)

Perhaps your wife needs bigger feet?

zapr

........Non cc Canadian car. There seems to be a slight amount of slack in the cable. I'll have to ask the guy who rebuilt the carb about the primary rods. Can someone explain about the lean stop and how to adjust it? The carb base I got from an 85 chev pick up. Thanks again......Zapr.

99Hawk120

Lean stop? Are you referring to the adjustable part throttle inside the carb that determines how far the primary rods can seat into the jets? I tend not to use it...

Sonix

iTrader: (1)

yes hawk, that's what I meant.

"use it"? I guess you mean you don't use it for part throttle mixture adustment eh? You just set it so the rods are "correct" in the jets and be done with it?
Me as well.

However, I have seen someone who, when rebuilding it, "tightened" that screw, until it bottomed. Not naming names , but it made it have a pretty stellar bog. Anyway, just throwing out ideas.

What part of Canada are you in?

99Hawk120

Yep, that's right, I set it at the same point that it was in the carbs that didn't have it. I forget what that was.

zapr

........Kitchener Ont. area. So the carb has to come apart to adjust?........Zapr.

Sonix

iTrader: (1)

Yep, if you suspect that. I'm not sure what would be causing your problems, as I'm not sure how they rebuilt it. I'd say it's a good idea to take it apart and see what was changed, or if something is missing, or screwed up.

Vader

Good thing he didn't answer "Quebec", since we all know that's not part of Canada... Can't fool us dumb yanks.

Sonix is on it. It's probably best to start from scratch, and assume nothing.