My 87 z28's 305's carb is mental.

(keep in mind, im open headers right now, so its frustrating with the noise)Its soo confusing. OK, cold start it idles at 1500, so i keep tryen to kick it down( for about 45 secs ) then it will die down to 700, then 5 seconds after, it dies right down.(choke light is on when it first starts, then its off tell is cold again) Driving on the road is fine, but when i hit a light, i have to put it in neutral just to rev it to keep it going.
I tryed fooling with the choke idle and the regular idle and they barley made changes. When i shut the engine off and start it again, its at 1500, and i kick it down, then it dies(sometimes i dont have to kick it, it will just idle down and die).

When i bought it off the guy it started and idled fine, but he said it would die after about 1 hour of driving(wich it did), So im really confused about what to do, im really hoping its just carb adjustment.
But where do i go from here.

Ask any questions if you couldent comprehend what i wrote lol.

Thanks,
c4maro.

 

I would try this. first get it to idle more at about 900 or 1100 rpm, if that didnt work, I would look for vacuum leaks( which probubly isnt the problem as a vacuum leak will make it rev higher "usually"). a cold moter thats carbed will usually rev hi for a bit. not sure how hi or how long but 45 sec and 1500 rpm dont seem bad to me. my 84 manual idels after a warmup at about 1000 rpm. maybe 900( its a tack). also make sure you have good fuel pressure.
if none of that worked I would call my bro mike and tell him this MF wont idle, but thats me.

 

You still have a stock Quadrajet on it?
There are three linkage settings you can mess with. The choke coil (the round black adjustment on pass. side), choke idle speed, and curb idle speed (when choke is pulled fully off.
First you want to set your choke coil. Do all this with the engine off. With a cold engine and air cleaner off, open the throttle all the way. The choke butterfly should close completely. Loosen the three screws on the coil housing and rotate it until the butterfly starts to open. Now rotate the opposite way until you get it to just close. Tighten the screws.
On the pass. side of the carb is an adjustment screw for the fast idle (choke closed). It's in a tricky spot and not always the easiest to get to. But where yours is at (1500 rpm) sounds fine, so if it's still there leave it alone.
After the engine warms up, your choke butterfly should open completely which will rotate the choke linkage and the fast idle cam will drop out of the way. Now your curb idle arm (front drivers side of carb) should be resting on the adjustment screw. If your idle is too slow or fast, adjust the screw in or out to get the rpm's where you want it.
Adjusting that idle screw in will speed up your idle. So if you weren't getting any idle speed response after turning it in, that means your idle screw is backed out so far and the linkage arm isn't even resting on it now. You need to keep turning it until the idle goes up. If your choke isn't opening when the engine warms up, then you need to look at other stuff. If the choke is open but not quite all the way, loosen the coil adjustment (three screws) and rotate it until the butterfly is fully open. Then see how it all works again with a cold engine.

 

Alright thanks, the carb is a carter AFB 4 barrel.

Ill mess with that stuff tommorow, i just hate working on it with the open headers.. in a small garage, its very loud lol.

Thanks camaro 69

 

Quadrajet or Carter, same basic adjustment procedures. But all the initial adjustments are done with the engine off. If you need to make any adjustments with it running, wear ear plugs!!!

 

Is there a default for the amount of times the choke idle and regular idle screws should be screwed in?-Example: like the air/fuel mixture screws-(Screw in all the way, then 1 and a half turns out)
Is there something like that for my carter AFB 4 barrel? For the choke idle and regular idle screws? Or is that just for the air/fuel mix. screws?

Thanks,

c4maro

 

There isn't an easy default for linkage adjustments. To get it right, it's more of an "adjust as needed" procedure. How the engine idles and how the choke opens and closes is what tells you where to go from there.

 

er lol. I needa get my exhaust fixed SOON.

My dog gets soooo freaked when i start my car, he shakes and just about has a heart attack, espeasicly when i try to rev it down to get the idle down. Hes a rott wieler too(dont think i spelt that right)

Those stupid screws dont seem like they make a differnece! ERR VVVV

You can see the little buggers in my sig too, there just staring at me saying IM NOT CHANGING THE IDLE HAHAHAH


GEEZ. srry

 

This should help you: http://www.edelbrock.com/automotive_...ers_manual.pdf

 

Whoa thanks, ill read it while watching th SUPER BOWL!!!!! GO STEELERS