havin' trouble with my carb?

[mountaindew]

For some odd reason my secondaries are not opening up on my carburator, even when I "floor it". When I do "floor it" it just seems like its flooding out or something. My friend seems to think that the problem might be the vaccuum canisters, if that is the case could I just replace those as a temporary solve until I get my replacement carb (whenever thats going to be ). Thanks for the help.

[Pamsdad]

I think we need a little more info here...

Holley? Rochester? Carter? Edelbrock?

Is it a VACUUM or MECHANICAL secondary carb?

[mountaindew]

Sorry, I don't know how that got left out but I'm almost positive its an Edelbrock and a vaccuum secondary.

[Pamsdad]

I'm not sure if Edelbrock makes more than 1 carburetor.

If it looks like an old Rochester Quadrajet, I know what were talking about.

This particular carb has a Mechanical Secondary Throttle Plate but also has a vacuum operated Air Valve on top. If your trying to get them to open while in your driveway, it won't happen. You'll need to see about 7500rpm in order for them to open.

Their might be a linkage problem. These carbs have a link coming off the choke to the secondary blades to prevent them from being open while the engine is cold(choke on). If the carb was recently taken apart, the linkage may have been put on wrong.

The way you describe what happens when you "floor it" tells me the secondaries are opening but too fast. Their should be a vacuum pull-off connected to the top of the secondaries(air valve). There is also a spring on the right side of the secondary air valve that may need to be tightened up.

A common problem on these carbs is the secondary air valve opens too quick, resulting in too much air and not enough fuel for that 1 second and finally resulting in a BOG.

Did ya ever hear anyone refer to that style carb as a Quadra-BOG?

They just didn't know how to adjust it correctly...

[mountaindew]

Thanks for all the info, my carb has two white "caps" that look like buttons one on each side and that is supposedly the vaccuum from what I heard... I think. I don't think its a Quadrajet from my understanding is that you need to be around 7500 rpm for the secondaries to open up. I've had my secondaries open @ a lot lower rpm than that. The odd thing is that when I first got this truck about 1 1/2 months ago it had more power, the carb wasn't doing this "bogging" down thing it just started getting gutless on me when I brought it home. Thats whats puzzling to me.

[mountaindew]

wait... I take that back it only has one white cap on the left side. Oh yeah, and its electric choke.

[broughy84]

Is this original to the truck or is it an aftermarket carb....the original carb on a chevy truck should be a Quadrajet.

[mountaindew]

I have no clue its a '76 chevy with a '69 327 so I'm guessin its stock but chevy never put 327s in their trucks to my knowledge. Is there a way I can tell what it is like a model number or something?