sbc 400 stalling out need HELP

[southern gator]

chevy 1976 truck. Im having a heck of a time.
Im stumped on this. idles fine at start up, drive it about 3 mins down the road and if u let off the gas at a stop light it will stall out. Start it back up with gas pedal down, it will stay running if u hold the gas pedal down. other wise it will stall out. sometimes it will drive ok and then start to spit and kick. Also if u let it set and idle for say 10 mins, all the sudden the motor will hesitate and shake then dead.
Fuel tank is good/clean, lines are clear, new mech. fuel pump, new fuel filter, new carb. and mounting gaskest. Cant find any vacuum leaks. replaced all rubber hoses. I dont think its vapor locking cause if i open the gas cap when it acts up nothing changes. And i got 10 psi of fuel pressure all the time no change.
ANY HELP GUYS??

[southern gator]

timeing is ok, new coil, new control moduler, cap and rotor

[INSIDIOUS '86]

what kind of carb are you running?

[78maliburat]

too much fuel pressure 5-7 lbs is good

[b454rat]

What does it idle at?? Almost sounds too low...

[Dan1969]

Sounds like too much fuel to me...

[J Knight]

What's the condition of the motor itself, new or old? Did it start doing this suddenly or over time? Did you change all those parts because of those issues with no effect? Diagnosing this problem may require a little more back ground info.

[Your41Plague12]

Definitely sounds like too much fuel. My neighbor's '55 was acting similarly, and it turns out his floats in his carburetor got messed up from NOT running an in-line fuel filter. All it takes is one piece of crud from the tank (albeit you say yours is clean) to mess a lot of things up. Next time it stalls and you have someone with you, open up the hood, have them try to start it, and watch your accelerator pump. At least on my neighbor's car, his was SPEWING gas out of the accelerator pump, leaking all over the top of the intake.

[southern gator]

motor has about 800 miles on it last built. I dont
think its over fueling because i have to pump the gas pedal
or hold it to get it to fire back up and stay running. I have
a inline fuel filter on it new. suddenly this happened truck
motor has been running great. I just replaced all the above parts
anit changed a bit on how the motor runs. Its a edelbrock carb.
600 CFM and its new and i have tryed other carbs. not making a
change. still have a problem. thanks for all the fast replys guys
also its idleing at 700 rpm

[J Knight]

A freind of mine had the exact same problem, I had a used engine I gave him and the problem went away. He swapped the motor and reused all of the parts that you changed on yours.
If you changed and cleaned your entire fuel and ignition system that only leaves one thing, the motor.
I know its rebuilt but its not impossible for something to go bad in the valve train.

[russgt]

having to hold the pedal to the floor while starting is a sign that its flooded. Since its a 76, you do not have a fuel return line right?

[southern gator]

no i anit got a return line, never had one on that truck, its only got the vent and pickup on the tank

[sandm2001]

my 76 did the same exact thing. my problem was a fuel line in between the gas filter and the tank. it was old and cracked really bad. truck would stall out or run really bad. thought it was the fuel pump, carb, etc etc same issue as you. maybe that's whats wrong with yours also

[southern gator]

i replaced all the rubber hoses, the only fuel lines i havent replaced were the steel lines.

[INSIDIOUS '86]

sounds like it may actually be running out of fuel despite what everybody thinks. which would make me believe that the fuel pump isnt working right despite being new or you have a float thats clogged shut. ( may explain ten psi) what kind os fuel pump due you have

[southern gator]

i have a mech. fuel pump. i have tryed 3 new fuel pumps now and two brand new carburadors

[INSIDIOUS '86]

and it still does it? hmm, you have hei right? test coil and the module the may be getting hot and then shutting down? lets go over our basics and verify what works corectly to narrow down our problem. will it idle without driving it with no probs?try to keep filling the carb with fuel while its running at idle see if it will run longer than normal, you will have to rig a funnel system for this but then its a delivery prob, check the ignition system and see if that changes anything?

btw what intake are you running?

[southern gator]

ok new cap and rotor, tryed two new coils and modulors i got spark no problem. im running a edelbrock perf. dual plan intake. it will start up and run, after a few mins. it will stall out and the fuel psi is 10 psi when this happens. If i drive it and I cant go far with out it spiting and kicking, gotta hold pedal to the floor and it still runs like crap

[southern gator]

it is hei, it will idle for a few mins. then all the sudden the motor will shake and stall out at idle.

[INSIDIOUS '86]

alright well while its running look down inside the carb from the top and when it starts to crap out see if there is fuel dripping inside, if not lets try and figure out if fuel is getting past needle and seat cause this still sounds like a fuel issue also try tighting (1/4 turn) your intake bolts starting in the middle and work your way out

[southern gator]

ok i will check this out tomorrow and post info. thanks again

[southern gator]

ok, i got up this morning and toke the intake off, intake looks good. Replaced the gaskest's, set timeing, ect.... still is acting up. im stumped guys. when it acts up and stalls out i anit seeing fuel dripping inside. now what??? thanks again for all the help guys

[notyo_cheez]

Adjust the choke?

[INSIDIOUS '86]

im as stumped as you. is your truck a dual tanker? try putting a rubber hose from the inlet of the fuel pump to a gas can that will rule out the rest of the system being bad

[southern gator]

i toke my dual tanks off a long time ago, running a 25 gallon fuel cell in the bed. tank is clean, and i have tryed running fuel out of a gas can, no change