4bbl Carb... help!

[retrovirus]

Okay first, I would like to say hello all! Okay here is my question I have a 1987 Monte Carlo LS with a 305 w/4bbl carb. My problem is that my secondaries on the carb won't open at all and I have no clue where to start..
Thanks.

[maxwedge]

Welcome to AF. They won't open except during full throttle accel, if you are trying it standing still in neutral, no good, no mention of how you are determining this.

[silicon212]

Furthermore, they will not open at all if the choke is closed or cold, no matter how hard you 'mash it'. If your choke vacuum pulloff isn't pulling, that can also lock out the secondaries.

[bobss396]

Gummed up linkage can do it too, but a bad vacuum pull off will do it more than anything. You can disconnect it at the carb, suck on the hose until the little lever actuates. Put a finger over the hose, wait a few seconds and if it doesn't stay, the pull off is bad.

Bob

[retrovirus]

Like when I am on a highway and floor it it like takes a while for it to start to go faster and i don't feel any difference and most ppl say you can feel and hear the difference when the 4 open

[retrovirus]

also the guy at the auto store said i need to rebulid it or just get a new carb but idk i kinda hope i can fix it cuz i am really low on cash i spend alot on gas..haha

[Scrapper]

i agree it's the choke pull off it's not letting the choke open as it should that's why you have to mash it. good luck...

[retrovirus]

mash it?

[bobss396]

Mash it = putting the pedal to the metal. Hitting the loud pedal, flooring it.

You know when it clicks in by the sound and sudden acceleration. With the car warmed up, take off the air cleaner and work the linkage that opens the secondaries. Sometimes it gets gummed up, but I agree with the first diagnosis posted here.

If you have zero carb rebuilding experience, get a quailty rebuild or have a shop do yours for you. Label all the hoses, etc (expect to break a few plastic fittings), take some pictures for reinstallation ease and take off the carb, which should be easy enough. I have a local shop that does a great job on Q-Jets. There is probably a good one in your area, ask around or make a few phone calls.

Bob

[silicon212]

Mash it - Punch it, stomp on it, put the pedal to the metal, wide open throttle.

Edit: Bob beat me to it

[Torch]

Originally Posted by retrovirus

Like when I am on a highway and floor it it like takes a while for it to start to go faster and i don't feel any difference and most ppl say you can feel and hear the difference when the 4 open

Oh yeah, you should feel it even with a 305, did it gradually get worse and worse or did it work one day then the next day it didn't? If it worked one day then the next day it didn't there should be something fairly obvious that went wrong.

[luxeryvic]

you can take the choke off and take that linkage out so the secondaries will open whenever

[Schrade]

Originally Posted by retrovirus

Okay first, I would like to say hello all! Okay here is my question I have a 1987 Monte Carlo LS with a 305 w/4bbl carb. My problem is that my secondaries on the carb won't open at all and I have no clue where to start..
Thanks.

Is it an aftermarket carb? Never heard of a carb on an '87.

If aftermarket, are the secondaries mechanical actuated, or vacuum actuated?

See if it was originally an TPI. I had one in my '87 vette, and it did just over 29 highway / 23 city, 24+ combined. You can get TPI setups for cheap on the web. 'FParts' / ebay, for one...

[silicon212]

Yes, the G-body was carbureted in 1987, last year for the G-body. 1988 was the last year in general for the carb and it was used then, only on B-bodies (though the Olds 307 motor used a carb through 1990 when it was discontinued).