383 misfiring when warms up? AHHHHHH

[dustin71]

Ok Gents, 71 dodge monaco 383 , 2 barrel, everything stock. Replaced the coil and plugs and wires last year along with cap and rotor. Just had the vavles cover gaskets changed and new thermostat installed. When i start the car up idles perfect, drive it for about 5 minutes drives prefect then all of a sudden when i step on the gas the car spits and sputters. im lost ive checked all the wires, made sure they are pushed on good. drove to my buddies house like this .. car sat for about an hour. started it up , ran great after 5- 10 mins started spitting and sputtering again. :sSig_noob:

Im trying my best , i love my car, I will admit i am over my head with an older car, but how else am I gonna learn. Ive fixed so much stuff on it that i cant talk to my wife about it anymore haha she cant stand hearing about everthing that keeps breaking ! lol

 

[detmatt]

Sounds like sediment in your tank is getting sucked onto the the sock on the sending unit and impeding your fuel flow. When you turn the car off the sucking stops and the sediment goes back to floating around the bottom of your tank.
Just a thought as I am dealing with this exact same thing in my Imperial right now.

 

[dustin71]

thats a great thought. should I check the fuel filter to see if there is and junk on it ?

 

[1978 NYB]

thats a great thought. should I check the fuel filter to see if there is and junk on it ?

Check it but definitely replace it. I replaced mine immediately after buying my NY'er and replace it annually.

 

[detmatt]

thats a great thought. should I check the fuel filter to see if there is and junk on it ?

Definitely would replace the fuel filter as it is cheap insurance, do that and go buy yourself some decent magnets and stick them to the outside of the tank at the low point. Sending unit comes out very easy and I would remove it and give it a quick inspection to make sure the filter sock is still intact. Make sure you have less then 1/2 a tank when you pull the sending unit though, unless you like a face full of fuel when you remove the retainer ring.

 

[dustin71]

awesome advice guys thanks excited to do this , this week. ill keep you posted

 

[dustin71]

well Im off to the states next week to grab a new carb and intake.. My car has the original carter carb on it, and am now in the process off making under the hood a little nicer. Was going to drop the tank myself untill i seen it was the size of a fridge. My Mechanic said the tank is clean. So im thinking the carb is screwed up somewhere. time for a new one.

 

[commando1]

This one's too simple.
Accelerator pump on the carb is shot.
When you start it up, the choke is letting you run rich which overcomes the bad pump.
Punch it, choke opens, bog city...

 

[dustin71]

it idles perfect ! .

 

[commando1]

it idles perfect ! .

As it should. The carburetor pump has nothing to do with the idle.

Sent using Forum Runner

 

[detmatt]

As it should. The carburetor pump has nothing to do with the idle.

Yep, Stan you're probably right on the money! I'm thinking my acc. pump could be causing some of my driveability issues, although the Imperial benefited from the other things that I did with the rest of the fuel system. I also benefited from a new vacuum advance.

 

[bluefury361]

well Im off to the states next week to grab a new carb and intake.. My car has the original carter carb on it, and am now in the process off making under the hood a little nicer. Was going to drop the tank myself untill i seen it was the size of a fridge. My Mechanic said the tank is clean. So im thinking the carb is screwed up somewhere. time for a new one.

I'd recommend a factory 4 bbl intake manifold and a new Edlebrock 600 CFM carb with electric choke. I even think your original 2bbl air filter base will fit back on.
The Edlebrock I intalled on my 69 440 did wonders for drivability.

 

[dustin71]

yea im looking at the edelbrock intake #2186 performer series. and carb edelbrock # 1406 600 4 barrel.. im so excited. heading down to the states this weekend ERIE PA no tax cant wait !.

 

[1978 NYB]

yea im looking at the edelbrock intake #2186 performer series. and carb edelbrock # 1406 600 4 barrel.. im so excited. heading down to the states this weekend ERIE PA no tax cant wait !.

I have the exact same setup on my 400. Right out of box and runs great. You might need an air cleaner extension depending on what air cleaner you are going to put on it. Most parts stores have a Mr. Gasket kit for $10. It's just a black plastic ring that elevates the air cleaner 1" so it doesn't hit the carb.

 

[dustin71]

ok im just gonna grab everything when im down there. for the intake I know i need the intake gaskets ! should i grab some gasket silicone also? and if so what kind will work best?

 

[1978 NYB]

ok im just gonna grab everything when im down there. for the intake I know i need the intake gaskets ! should i grab some gasket silicone also? and if so what kind will work best?

No intake gasket used, just a valley pan gasket that is a stamped steel. I use Fel-Pro products. Yes, they make intake gaskets, not necessary on a B/RB engine. You'll see that there isn't one when you take your intake off. Any silicone RTV will do. You only need a bead on the front and rear surface of the block.

 

[dustin71]

ok .. thanks im so excited. hopefully i can get some pictures up when i come back !

 

[detmatt]

Where in the states are you coming to buy these parts?

 

[dustin71]

grove city PA and erie PA.. tax free ..

 

[mdh157]

Definitely would replace the fuel filter as it is cheap insurance, do that and go buy yourself some decent magnets and stick them to the outside of the tank at the low point. Sending unit comes out very easy and I would remove it and give it a quick inspection to make sure the filter sock is still intact. Make sure you have less then 1/2 a tank when you pull the sending unit though, unless you like a face full of fuel when you remove the retainer ring.

Matt, what is the purpose of sticking magnets to the outside of the tank? Aren't we talking abt dirt here? what am i missing?