1988 caprice problems

[sm88/4bbl305]

Hey everybody, my caprice has a 305 in her with the feedback 4 barrel rochester carburetor. My carburetor was in need of a rebuild and my car eventually started dieseling, i hoped this was a cause of the carb, so i rebuilt it about a month ago. I adjusted the hot and cold idle to spec and adjusted the mixture with the two adjustment screws. I also had to replace my choke. The dieseling was no longer a problem. After a few weeks i adjusted the mixture again. Now my car is starting to diesel again and don't know what would cause it. Im thinking about just lowering the hot idle a little bit, but don't know if it's the right way to go about doing it. She's also leaking quite a bit of oil too, i think it's coming from the intake manifold but am not sure. Does anyone know if this was a common problem on 305's? I'm really hoping that my car isn't burning the oil, but i can't smell it and there's no smoke, but my car is making a new knocking noise every once in a while. Any info or comments are well appriciated. Thanks

[PeteA216]

Is the knocking when the engine is under load, when its cold, idling? To stop dieseling, try to lower you idle (unless its about as low as it can go) or to lean out your mixture a little.

[poordudewhowantcar]

dude ill help you out
i own a cutlass with a 305 2 bbl i know its not fast but a i added a low end cam to it
the first thing i did was retard the timing just a bit
then i adjst the idle screw that helped a bit too
then i cleaned the carb with carb cleaner spray and reoiled it with wd-40 and since then i havent dieseld make sure that when you think you fix it heat it up and run it up hill if you detonate or fell sluggish you got something wrong

[poordudewhowantcar]

if you cant fix the problem before you park put it in "N" and rev it up then shut it off and park it..
this doesnt fix the problm but it helps for a while

[capriceforever]

I've encountered two things that could cause diesling/ run-on. One is the curb idle is set too high (bottom right hand side of carb). Its the screw with a spring behind it that holds the throttle out. If this has been played with, it may have to be turned out a bit. If you adjust it, just remember where you started, count your turns.

Also, if your car has A/C, it has a throttle kicker (front right hand side of carb on top). Its mounted on the side of the carb. The plunger extends when the AC is on, causing the throttle to increase so you maintain a smooth idle with the extra load of the AC. If that plunger is sticking (gunked up) by chance, it would hold the throttle out slightly after the engine is shut off.

Two simple things you might want to check before you spend any $. Good luck.