Hello all, I just bought a 1966 Dodge Coronet with its original 318 and automatic transmission. I drove it 3 days with absolutely no problems at all. Then yesterday afternoon I noticed the brakes were kinda soft so I added a little bit of brake fluid to the cylinder. Later that night I took it for a drive and it stumbles terribly upon acceleration. It starts, idles, and revs up in neutral with no hesitation or stumbling. But when the car is put into drive and you try to give it some gas it stumbles and bogs down. I am a little perplexed as to why the car suddenly stopped working properly. Does anyone have any suggestions on what could be wrong.

Travis

The carb on most poly's suck.
That being said, there are several possible reasons.
It could be the accelerator pump.
Could be a vacuum leak.
Could also be a worn out carb that after driving, something held together by varnish gave way.

I guess I need a little history to guess what else it could be.

You just got it, but what was its life before?

check the accelerator pump on the carb...went you move the throttle linkage the pump should squirt gas...

it will rev in neutral was miss adjusted pump do to no load on engine...

check the acclrator pump,it might be going south

I had trouble with 2 carbs latly with the cheap gas they are clogging up air bleeds and the floats are sticking

may want to check the condenser if it has points,mine did that also,start,idel,would throttle blip fine but would shake pop and barly go when in gear

50$ service bill for a 50 cent part,first place I look now

may check your cap and rotor,wires and plugs while your at it

has it been sitting around some?,thats when I find the gas is going bad fast and the trouble started with mine

but most likly the pump in the carb,look for a good squrt of gas when you pump the throttle,with the engine not running

maybe check it with a vac gauge on the vac nipple on the carb with it running,

check you timming with a light or pull your #1 plug,up on top dead center,look to see if timming marks line up on the t cover and see where your rotor is pointing to rule out it jumping time,it will run jumping one tooth but not very good,2 teeth and it wont run

look at your fuel filter also...

thats some ideas to start you checking maybe

good luck and post an update with it later

How long had it been sitting b4 you bought it? You may have churned up some old crud in the gas tank that is just now affecting performance. I agree with Andrew though. Its hard to say without a little more history.

The history of the car that I know of is that the previous owner brought the car up from Texas a few years ago. He repainted the car and would drive it on the weekends and to a show here and there. He left the engine stock. He only drove it about 10 times this summer and it was sitting for about a month. He said he has never any problems driving it. I drove it about 200 miles in the last few days, and put about 8 gallons of gas in it. I did put 87 octane in it, perhaps I should put a higher octane in it? I pumped the throttle with the engine not running and a good squirt of gas shot out. The fuel filter is good. I will check the other suggestions and see what happens.

The gas wont do that, as long as it doesnt ping 87 is fine.

just out of curiosity does it have power brakes or manual?

I'll bet the E10 fuel has caused issues with your carb. I'll also say that you have a points ignition problem, easily solved with a Pertronix kit.

Gasoline is too expensive, learn about octane ratings.

check the condenser and points

make sure they are set right and in good shape

check to make sure the choke is not sticking closed

also look for vac leakes around the intake and carb base,a propane torch works

my carbs were varnished up very bad and started acting up a couple months ago...may need a looky see inside of it

but it pumping fuel is good,so I would look at the ign sytem maybe