starting issue with mostly stock 318

[str12-340]

I am working with a mostly stock 318 in a 1970 Dart - add LD4B, Edelbrock 600cfm, Edelbrock performer cam, Mopar electronic ignition.

Engine was rebuilt 15,000 miles ago. The engine runs just fine once it starts.

When cold, tap the gas to set the choke, engine starts right up, no issues.

When driving around and making stops, if the car sits from 5 to 30 minutes, the starter grinds and grinds and grinds, then the engine starts up, runs rough for a bit, then runs fine.

Unlike my other Darts, this one still has an original type starter. Once the engine starts the ammeter pegs at charge and relatively quickly comes down to just a bit above neutral and stays there while running. With the engine running after the ammeter comes down, the battery reads at 14.5 volts, turn it off and it reads 13.5 volts.

Suggestions for causes for the hot start issues???

 

[toolmanmike]

Edelbrock 600. The fuel is probably vaporizing. You might want to try a carb insulator between it and the intake. It is a hot soak issue. The voltmeter charging big after grinding the starter is perfectly normal.

 

[toolmanmike]

Look in the fuel forums. There is a sticky with information about installing a charge pump to help with fuel evaporation. Both cold start and hot soak.

 

[str12-340]

for many years I have had a vane type electric fuel pump that I only use to fill the carb before starting. It doesn't seem to help in this case. I have driven this car for 65,000 miles since 1989. This is new...

 

[Mattax]

Check the voltage during start. The battery may be at the end of its life.
See Dana's thread about his car's old battery.

 

[Mattax]

This one.

6.5 years on a battery - new personal record!

Short story.. My dart has had some odd charging issues lately. The issue was high current in the ammeter but low voltage at the battery. I checked out everything and am satisfied the battery is the issue. Changed it and the issue went away. Now the ammeter reads slight charge right after...

www.forabodiesonly.com

So worth seeing how well the battery is handling the load by checking voltage during the start.

That said, I'm seeing similar on my Jeep - a very brief swing to high charge immediately after a hot start - and that battery is was bought just a few months ago.

 

[Bewy]

It is NOT fuel evaporation. If the engine starts cold with a tap on the pedal, it tells you there is fuel still in the carb.....& the fuel did not evaporate after the last time the car was driven.
If the engine ' grinds & grinds', it suggests the battery is ok.
Next time, do this: remove a plug lead. Stick a screwdriver in the lead & lay it across the valve cover [ or similar ] to create a 1/4" air gap. Crank the engine & check for spark.

 

[Dave999]

do you still have the start wire connected that feeds 12 volts to coil at start?
sounds more like slight flooding to me. do you get any evidence of moisture at the tailpipe when it eventually starts or black splatters on the ground... start it with the tailpipe near a white garage door and you will soon see...


Dave

 

[Oldmanmopar]

I covered this many times. You need a return, The needle and seat cannot work due to the boiling fuel. and the pressure dead ended up against the needle. Been there with many carbureted cars. With a mechanical pump you need a return filter pictured here being install on a 408 Barracuda.

for an electric pump you will need a return regulator second set of pictures 416 with a 100 gallon per minute electric pump.

 

[RustyRatRod]

I covered this many times. You need a return, The needle and seat cannot work due to the boiling fuel. and the pressure dead ended up against the needle. Been there with many carbureted cars. With a mechanical pump you need a return filter pictured here being install on a 408 Barracuda.

for an electric pump you will need a return regulator second set of pictures 416 with a 100 gallon per minute electric pump.

View attachment 1716422581

View attachment 1716422582

View attachment 1716422583

View attachment 1716422584

View attachment 1716422585

Steve is right. A return will not hurt a thing. Also another suggestion. What base plate gasket are you using? If you have the thin one, switch to the thick Edelbrock gasket. Edelbrock 9266 is the part number you need.

 

[Oldmanmopar]

Everything recommended will help. Before adding the return on my race car. I installed. Heat wrap on all the fuel lines. Mr Gasket base gasket and the carb heat shield.

I did not want to buy another $200 in braided hose or the new Return regulator and all the AN fittings to hook up the new line. I had the bung in the tank. and adding the return was my last resort. I was at the point when going round after round I was afraid to shut it down between runs. I was shutting off the pump and turning it back on and off until cooler fuel reached the carb.

So then I made the commitment. After the upgrade I could reach in the car at anytime and hit the key and it would fire right up and idol perfect.

Todd's yellow barracuda pictured above is being driven in this heat. Never once has it had a problem starting after warmed up.

The floats will not work properly with boiling fuel and the car floods its self when sitting for 5 -10- minutes with the fuel pressure being dead ended up against the needle and seat. The floats will only start working again when cool fuel reaches the carburetor floats. I put returns on every car I build.

Chrysler started putting these filters on all late 70's - early 80's for this reason.

Buy a filter for a dodge ram with a return. Install a 1971 vent line to the tank. Use a 1972 up gas tank that has a return nipple above the sender. Or a sending unit with a return nipple

first 2 pics bellow are before the return the rest are after

 

[Dartswinger70]

I'll second the isolator gasket helped on my Edelbrock carb. Ethanol fuel boils off fairly easily.

 

[Inertia]

I found the usual cause by your symptoms to be syphoning.
Hot. After shut off, look down carb throats. you'll likely see fuel slowly dripping down the barrels, thus flooding, causing long crank, and initial ruff running.
Blow out the bleeds, maybe lower float/rebuild . Check float weight.

Good luck.

 

[318willrun]

I guess overloading. Sounds like fuel is dripping in when it's off and pressurized. That would explain why after cranking it runs rough for a few seconds.

 

[str12-340]

What I find puzzling is that I have been driving this car for years and this is a new issue. I'm going to try the isolator gasket recommended before considering a whole return system. Is it possible that the carb is just worn out and the heat soak is building pressure in the carb and leaking fuel into the intake? I was thinking the fuel bowls were vented and this would reduce the pressure?

 

[toolmanmike]

What I find puzzling is that I have been driving this car for years and this is a new issue. I'm going to try the isolator gasket recommended before considering a whole return system. Is it possible that the carb is just worn out and the heat soak is building pressure in the carb and leaking fuel into the intake? I was thinking the fuel bowls were vented and this would reduce the pressure?

Did your fuel change? There is a convenience store here that changed their premium blend and reduced the octane and everyone with old cars has ben having fuel related issues.

 

[Bewy]

Certainly no need for a 100 gph pump for a 'mostly stock' 318. 100 gph supports 1200hp!!

 

[RustyRatRod]

What I find puzzling is that I have been driving this car for years and this is a new issue. I'm going to try the isolator gasket recommended before considering a whole return system. Is it possible that the carb is just worn out and the heat soak is building pressure in the carb and leaking fuel into the intake? I was thinking the fuel bowls were vented and this would reduce the pressure?

How long has it been happening? If it not terribly long, is it possible you got some bad gas?

 

[Dave999]

or a tiny bit of corrosion or aged fuel pipe is holding the needle valve open slightly
or the pump has hammered a ridge into the needle valve and it no longer cuts off the fuel when the float is up.
or the float is full of fuel, if its a modern spancil plastic float, maybe its outer skin has ruptured and its filling up like a sponge. these don't sink like an old brass float they carry on working just at a lightly lower level in the bowl

all will produce a level of flooding that takes a long time to chuff away out of the exhaust when you try to start. any pressure from pump to carb at switch off bleeds into the bowl and flows fuel into the inlet.

hop out, filter off, open throttle and choke and watch for dribbling from the top end of the carb not the accelerator pump squirter which you just activated, but whatever slot venturi pipe or ring with holes in etc your carb has to distribute fuel from the main jet.
Easy checked before spending more money.
what worked 6 months ago doesn't work now something wore out, partially failed or got
stuck.

i personally think bad fuel would be hard to start when cold or hot, But you never know....
if it was water in the tank you can't start on water and it sinks to the bottom when left to stand

Dave

 

[Dartswinger70]

try cranking with the throttle wide open? that may narrow it down to flooding if it fires up with a puff of smoke etc.

 

[str12-340]

Thanks to all! I'm still working away at this. Isolator gasket is in the mail. I'm going to work on looking down the carb after shut off to check for raw gas drip today.

 

[DartGTDan]

My 318 with an Edelbrock LD4B intake & 1406 carb also has the 9266 thick spacer/gasket.