I have an 82 Elky with a completely stock 305 and original four barrel carb.
Lately, at various times, when I pull up to a traffic light, sit there for just a minute, give it the gas to take off, it hesitates badly, almost dies, then takes off and runs fine. If you just very gradually give it pedal it doesn't seem to do this, but just normal take off gets the big bog, although not every time.

About the same time this started happening, I noticed at times when I would slow down to turn a corner, it wouldn't downshift when it should and would try to pick up speed in drive when it really should have downshifed to second, unless you give it more pedal than necessary, then it WILL downshift and go on.

Does this sound like a carburator problem, like a bad excelerator pump,
or could it be a bad sensor or solenoid of some kind causing both problems? I know from experience a bad sensor or solenoid can cause wierd things to happen that seem unrelated.

Or, do I have two separate problems? Any ideas what I should look for or try to test? Any help is appreciated.

Is it cold in your part of "USA"?


If it is, check that the THERMAC system on the air cleaner is still working. Make sure the duct going from the snorkle to the exhaust manifodl is still there. Without the heated air, the car will bog whe it's cold outside.

HTH,

Hi that sounds like the problem that I had with my 78 Lincoln Town car. The problem with that I would get to a stop sign and than the thing sounded really nice and what not but than I would try to take off and the thing would kill. I would start her up and than I would gradually start and it would run great. So I learned that with that 460 with 4 barrel to start slow. One day I just decided that the carb was in need of cleaning after talking to enough people saying it was probably carb adjustments. Than after it all I determined that it was actually the floater inside the carb. If you are looking for a good project to do on your car that is something that takes a few hours. Go to a parts store where you trust something like Carquest which I prefer and purchase the carb kit and than also buy the floater. They are sold seperately. It will cost about $30-$40 so kinda cheap and it will most likely fix the problem. The carb set normally has instructions so it is painless. DO NOT go to Checkers for carb kits I have had to many bad experiences from them on carb kits. Have fun working on the carb.

B4black,

I checked to see if the air cleaner thermac was working properly and it appears to be so. Yes, it does have the heat tube from exhaust man. to snorkel in place. Thanks for your input though.

hot78elcamino,

You may be right about the carb. My friend is pretty knowledgable and he thinks its a gummed up power valve in the carb.
Whatever it is, its getting worse every day.

Time for a complete carb. rebuild.

My friend is pretty knowledgable and he thinks its a gummed up power valve in the carb.
Whatever it is, its getting worse every day.

You may want to let your friend know that you have a computer controlled carb that doesn't use a power valve.

I would for look for vacuum leaks and check every sensor before messing with the carb. My experience has been that once you mess with them, they are never quite the same. I would search the junkyards for a carb that has all of the adjustments plugs still in place. If the mixture plugs in the base have been broke open, don't use it, IMO. This is a sure sign of someone appling old school know how to a new school carb. (new being a relaitve term.)

You can probably get a good used carb off a 305 for just a little more than a rebuild kit. And it's a lot less work.

The carb may never be the same again however remember do you want it the same? The carb being rebuilt you want it to run better not to run the way you just had it. Going used you don't know what the problems are with that carb and yeah use some of the parts that may be worn on yours with that one but you still want a new floater and stuff in that carb. That is one major performance part that noone ever thinks about going out. Trust me I know cause I had to also rebuilt the carb on my 79 El Camino however that is just a simple two barrel carb so nothing major. So I still would recommend keeping the car motor as original as possible. That is my opinion at least. Can the body to suit your color choices but keep the motor the same with that much performance. Have fun with the carb rebuild. Josh

Check the accelerator pump on the carb. It sounds like its worn out. You can get a kit or a new pump from your local autoparts store and they are pretty easy to rebuild or replace. Its just a small "leather" cup on a shaft and it gives the carb the "extra" shot of raw fuel for acceleration purposes and that is pretty much the only reason that you have one on a carb.

That is my best guess. We are talking about a truck that is 20 + years old.

Rebuilding the quad is no big deal. Before I changed to a edelbrock, I rebuilt mine about every two years.

i just started having that problem a few weeks ago almost same exact thing. kept checking and replacing.finally decided to pull the timing chain and gear .found the problem.would replace something would run ok for a bit then it got worse after every replacement.

must be a combination of things. keep the updates coming folks, I'm about to start working on the same thing. :(

I wonder if it's worse for 5th gen's or what.

Well, Ihad the carb rebuilt, and although it did need a rebuild, that didn't fix the hesitation problem. Also found a bad rotor bug in the distributor and replaced cap and rotor. Still no fix.

Took it to a trans. shop today. I have a 350C tranny in mine (has a lockup type converter). They took the pan off and found a lot of metal shavings which caused the electro-magnetics in the lockup system to attract the shavings and screw everything up so the converter was wanting to lockup as soon as I took off, thus the big bog!

Guess its time for a tranny rebuild and lots of dollars to be spent!

Hope you other guys with the bogging problems have better luck and cheaper remedys than mine !

Total bummer dude, Time for a upgrade?

Yea, that IS a bummer dude, BUT you have your solution! Shop around, and make alot of calls for the best deal. Remember, the cheapest deal isn't the best deal.

You may want to try a complete fluid flush/exchange and filter replacement before shelling out the big bucks for a rebuild. Occasionally these old gals will run a long while with new juice and filter. :)

Well, Ihad the carb rebuilt, and although it did need a rebuild, that didn't fix the hesitation problem. Also found a bad rotor bug in the distributor and replaced cap and rotor. Still no fix.

Took it to a trans. shop today. I have a 350C tranny in mine (has a lockup type converter). They took the pan off and found a lot of metal shavings which caused the electro-magnetics in the lockup system to attract the shavings and screw everything up so the converter was wanting to lockup as soon as I took off, thus the big bog!

Guess its time for a tranny rebuild and lots of dollars to be spent!

Hope you other guys with the bogging problems have better luck and cheaper remedys than mine !




Just another update------Tranny didn't have to be rebuilt after all. The lockup torque converter was disintegrateing and thats where all the metal shavings were coming from.
They did take the tranny all apart to check it out and clean it but found nothing wrong with it.
Still won't be a cheap bottom line but still less than a rebuilt tranny would cost!! Yippee!!!