340 starting issues

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bluesuitah

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Looking for some advice. Recently started having problems starting my 418 stroker. It has a holley 750 double pumper. I have owned the vehicle 5 or so years. No troubles previous. Last fall died on me while driving. Turned out to be ignition module. Replaced that over the winter. Fired up fine this spring (stored with fuel stabilizer) then started to have problems starting it when the engine was warm. Engine would turn without really trying to kick off and eventually flood. I’ve owned the car for 5 years and it was never finicky with starting. Now it doesn’t want to start cold at all. Checked that it does have spark and it very briefly tried to start once during my attempt today. I’m thinking ethynol ruined something in the carb but I don’t know enough about them…thoughts? Otherwise I’ll be asking about references for Holly rebuilder on here. Thanks.
 
If the dist has VA & is connected, the wires get flexed during operation & eventually break-no spark.
 
Have another carb like an Edelbrock 1406 to throw on it for a quick startup test?

Process of Elimination

Sounds like a plugged up fuel system/ plugged up carb.

Could be sediment in the carb, needs to be cleaned out.

How old is the fuel tank on the car, they do rust and scale up over time.

Fresh fuel filter?

Water condensation in fuel? Ethanol fuel draws moisture out of the atmosphere.
 
Dribble a little gasoline fown the throats of your carb, see if it will quick start doing that?
 
It has spark, don’t have another carb. Seems to be getting plenty of fuel as carb it noticeably wet. I’ll try again tomorrow and see pull some plugs to see how wet they are. Has anyone had similar problems from the shitty fas affecting their carb?
 
I take a quart tin chemical bottle with a gas line soldered to it and make a temporary clean gas supply hanging from the hood with a wire.

Now there is clean gas, without the fuel pump supplying the carb, to test and fire up the engine. Have to allow some air in the cap on tin bottle, so leave it a little loose.

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Like the Edelbrock carbs, they are very easy to pull the tops off the carb, and clean the grit out of the bowls and spray out the jets. Clean fuel and give it a go again.

Compression, Ignition, and Fuel is what makes them run.
 
Did you see my question about vac adv in post #2??
That can give intermittent spark & lead you in the wrong direction.
Disconnect the p/up wires & check the resistance of the p/up; should be 140-1200 ohms depending on brand. Wiggle wires aggressively while watching the meter. If resistance changes, p/up is bad.
 
Even with fuel stabilizer the gas will be NFG after a few months. It won’t even light with a match when poured on the ground. At least here in commiefornia.
 
Has anyone had similar problems from the shitty gas affecting their carb?
no. Ran it for two decades no problem; same carb, same pump, same tank, same everything.
BTW
after several attempts, like this; the fuel has washed the oil off the rings and walls and your compression is gone. You will need to restore the oil-seal to get the cranking-compression back up.
 
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Update. Thanks for the tips btw. Car sat for several days, went out slight touch on the pedal and it fired right up. Drove around for an hr and then wanted to see how she started warm.
Without giving it any pedal it immediately wants to start but doesn’t catch like there’s fuel to start but not nearly enough to kick it off totally. Give it a little pedal and then it just turns over like I pumped it to the floor ten times. After going between hints of pedal and no pedal at all attempts it finally started again.
 
If the dist has VA & is connected, the wires get flexed during operation & eventually break-no spark.


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If the VA has not been used, you will not have broken wires. The VA connects to a carb port.
 
Check your engine oil level and see if it smells like gas. You do not want liquid gas in your oil pan. Will not cure your present problem but it may prevent a future one.
 
Here’s an update. Found a work around. If the engine turns over like it’s not getting spark While leaving the key out of off position I cycle the gear selector (auto on column) to 1st and then firmly back to park and it has started every time. Runs beautifully otherwise. Haven’t had time to investigate further.
 
It has spark, don’t have another carb. Seems to be getting plenty of fuel as carb it noticeably wet. I’ll try again tomorrow and see pull some plugs to see how wet they are. Has anyone had similar problems from the shitty fas affecting their carb?
Did it ever backfire? Holley's have power valves that can blow out causing some strange issues. Oops, I should have read all the posts before commenting.
 
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