Cont. I must be missing something

[Coronet 14]

Due to medical issues I haven't been on here for a while. But things that have been checked for carb backfire. Compression good, Vacuum leaks fixed found old roller bearing shoved in vacuum hose weird. played with timing made backfire worse. Set back to where I had it. Same with vacuum advance. Adjusted carb jets. set underhood insulation on fire Bad no marshmallows. Carb still intermittent backfire. Pulling carb off next week. Gonna have checked and bench flowed. I would put a larger motor in this car but I want to know what is going on I won't surrender.

 

[daredevil]

throw a vaccuum gauge on it. May be a sticking intake valve. Heres a chart for reference. You can tell a lot from vaccuum.Of course it will be low if you run a big cam.

 

[Coronet 14]

So far vacuum is 10 at idle

 

[daredevil]

Has the timing chain been replaced recently.Maybe a tooth off.Or if chains old maybe stretched?

 

[MikeyT]

I am sorry, I didn't see the initial post, so maybe these details are known but to catch me up... What do you have the timing set at right now Initial and advanced? When does it backfire? Details about the engine?

Mike

 

[Coronet 14]

It's a 72 Coronet 318 2 barrel carter carb reman. with 904 trans with factory a/c setup. If you are at half throttle and go to full throttle it's ok. If car is at a stop or idiling and you step on it it backfire through carb 2 out of 3 times. If you ease into it it's ok.

 

[roadrunnerman]

I'm thinkin' it's in your carb. Accelerater pump rod/gasket?

 

[67 coronet]

i am with roadrunnerman.take off your air cleaner and look into the carb while you slowly actuate the throttle by hand.NOT RUNNING.key off.you should see a steady streem of fuel from the squirter inside the carb.it should start the second you start to move the throttle.if not,or hesitates.that is your prob.

 

[daredevil]

i am with roadrunnerman.take off your air cleaner and look into the carb while you slowly actuate the throttle by hand.NOT RUNNING.key off.you should see a steady streem of fuel from the squirter inside the carb.it should start the second you start to move the throttle.if not,or hesitates.that is your prob.

i,m with him^^^

 

[Coronet 14]

i,m with him^^^

Also if the car sits for a day or longer it's tough to get started. Once you get it started it's good it will start all day with no issues. Except for the backfire.

 

[Coronet 14]

Carb shoots gas. I don't think it's getting enough fuel. I can spray starter fluid in carb after car has been sitting a while and it fires right up and stays running. The manual doesn't talk much about the carter carb.

 

[67 coronet]

could be low floats or leaking fuel out of carb while its sitting.rebuild the carb would be my next guess.you would need to check for cracks as well.pretty easy to rebuild a two barrel carter.

 

[Coronet 14]

So much for remanufactured. Once carb is right it will be easier to work on timing.

 

[Coronet 14]

Done pissing around with that POS 2 bbl. Just ordered 4 bbl intake and carb with electric choke from Summit. To bad they can't helicopter parts to my house.

 

[Coronet 14]

View attachment 114453Found intake leak. Carb NFG. I'm having someone helping me with this. Do to my arthritis and other stuff acting up real bad. I'm requiring help on this one.

 

[69roadr]

let us know if the problem gets solved with the 4 bbl. setup, pics too

 

[Coronet 14]

Sure will. Hopefully drive next weekend. I'm ordering my suspension parts from Mancini racing next week.

 

[Coronet 14]

Had to get a 3/4 short pipe for thermostat bypass hole for 4 bbl intake manifold from Home Depot. Who new they sold car parts Apparently the one in old one in stock manifold doesn't come out. Not gonna say what it looks like screwed into new manifold. Why is one side stepped up on the inside of intake higher than other?