Hard to start after sitting

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Jay E.

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72 Duster 340. If used every couple of days it starts easily in the morning. But longer than that it cranks and cranks as though the carb is empty. Possibly because the crappy gas has evaporated?. Should I install an electric fuel pump to fill the bowl before cranking? Any suggestion on the pump and mounting location? Should it be on the key and run full time or on a switch?
 
I would guess you have an Edelbrock/Carter carb ? Same thing with all of my Edelbrocks. Not sure why but I assume it has to do with the jets being in the floor of the carb .
Don’t seem to have the issue with my Holleys .
 
72 Duster 340. If used every couple of days it starts easily in the morning. But longer than that it cranks and cranks as though the carb is empty. Possibly because the crappy gas has evaporated?. Should I install an electric fuel pump to fill the bowl before cranking? Any suggestion on the pump and mounting location? Should it be on the key and run full time or on a switch?
Yes, the crappy gas has evaporated.
 
I would guess you have an Edelbrock/Carter carb ? Same thing with all of my Edelbrocks. Not sure why but I assume it has to do with the jets being in the floor of the carb .
Don’t seem to have the issue with my Holleys .
That sure has a lot to do with it.
 
72 Duster 340. If used every couple of days it starts easily in the morning. But longer than that it cranks and cranks as though the carb is empty. Possibly because the crappy gas has evaporated?. Should I install an electric fuel pump to fill the bowl before cranking? Any suggestion on the pump and mounting location? Should it be on the key and run full time or on a switch?
This takes care of the issue. Electric primer pump for fuel
 
My 65 235hp does the same thing. Original Carter AVS. I’m pretty sure the fuel is evaporating from the float bowls. Running ethanol-free gas makes no difference. It’s getting an electric pump as soon as I get the new transmission installation sorted out.
 
I would guess you have an Edelbrock/Carter carb ? Same thing with all of my Edelbrocks. Not sure why but I assume it has to do with the jets being in the floor of the carb .
Don’t seem to have the issue with my Holleys .
It has the original TQ, which I was hoping would stop this with the composite center section. But no luck. Thanks for the pump suggestions, I'll install one.
 
1st the walls of the intake manifold dry out.
I doubt the carb bowl has dried out.
if so, an electric pump is a poor band out.

Take the air cleaner lid off, or the entire air cleaner.
Take a look at what is going on.
Work the throttle.
Is there a pump shot on the first throttle opening?
How about hte 2nd and third.
No? Then look in the bowl. is the fuel level low? Is pump intake covered?
No - then fuel level is low.
Yes - then the pump check ball or valve isn't holding

How 'bout the choke settings? Chokes are tricky to get perfect, and the automatic ones trickier - especially when not factory.

Bottom line is that if there is fuel in the bowl to the proper level then an electric pump isn't going to do a thing to help.

One more possibility. Summer fuel in winter weather. Yea. That crappy cheap winter fuel does have higher RVP to help with starting. The downside is those components when sitting evaporate out of the intake and even the bowl faster than summer mix.

All that vapor trapping stuff that started getting added in the early 70s (earlier in Calf) reduces this problem.
 
Just fill the float bowls up. It's not a problem, and you can check fluids and look it over while under there.

To me this is better than installing an electric pump, more lines and wiring, another leak point, more things added on.
 
Let's manage by fact.
  • Define "cranks and cranks"
  • BEFORE you try to start next time that you expect to have a problem, take off the air filter and rotate the throttle while looking down the carb. Is there fuel squirting out of the accelerator pump jets.
  • To see how fast the "tired old mechanical fuel pump" can fill the carbs. Sometime take the fuel line off the output of the fuel filter and extend it to a bucket. Get a remote starter switch and put it between batt positive terminal and the lug the Yellow wire was on on the starter relay and crank the engine. Have some one with a stop watch measure a few seconds, 5 would be a good number. Now measure the amount of fuel in the bucket.


Standard operating procedure for starting my 67 273 2bbl.

If it has beed started in the last couple days.
  1. 2 pumps and crank for a few seconds.
  2. It will usually start right up
  3. If it does not start repete step 1
  4. It will start.
If it has sat for a couple weeks

  1. 2 pumps and crank for a few seconds.
  2. 2 pumps and crank for a few seconds with throttle 1/2 way open
  3. It will usually start right up
  4. If it does not start repete steps 1 & 2 be careful how many pumps you give it as you can flood the engine.
When I say a few seconds I mean maybe 2-3 second bursts. There is never a need to crank for 5-10 seconds.

The stock V8 fuel pump should be able to produce 1 quart of fuel in one minute

Screenshot_20250118-083241.png


That is 250 pumps of the fuel pump plunger per minute or 4 per second

That is 1/2 oz in 1 second.

8 seconds would produce the 120 ml the video is putting into the bowels of a Holley.

Mt theory....

Car ran a few days ago.
Carb is mostly to full with fuel.
There is / may still be some fuel vapor in the intake.
2 pumps adds more fuel vapor to the intake.
Now it takes a few seconds to get the fuel vapor to the cylinders
And it fires

Car sat for a few weeks
Carb is probably not bone dry.
Intake has no fuel vapor in it
2 pumps adds fuel vapor to the intake.
Now it takes a few seconds to get the fuel vapor to the cylinders
But there is not enough so 2 more shots some more cranking
And it fired

Car sat for a months
Carb is probably bone dry.
Intake has no fuel vapor in it
Now would be the time to fill the bowels manually.
And put a small squirt a couple ml of fuel directly into the intake. Both sides if it's not an open plenum

You only need to do this 2-4 times a year, so why go to the trouble of adding an electric fuel pump.

The parts you don't add, don't cause you no trouble!

BTW... As for alcohol gas vs no. Alcohol gas. It WILL / can make a difference when running in hot environments but probably not be a too much of a problem with starting.
 

OK this should make an interesting conversation on the subject as I have dealt with this problem myself.

1976 Dodge D100 with an '89 318 Roller Engine with and Edelbrock 1406 4 bbl and Mopar Electronic Ignition and ballast resistor. Foam Dome Air Cleaner, evaporates the fuel out the top after sitting more than 24 hours, creating crank crank crank hard starts.

Now had a same year '89 318 roller (in a '89 D100) with the 1406 4 bbl converstion and manual fuel pump and the Mopar HEI Distributor and high powered E-Coil, no ballast resistor straight 12 volts to power it. This one has the small chrome top air cleaner for less evaporation. Always instant starts even after sitting for a few days.

Both engines have the fast turning mini starters of '89 Trucks.

1976 D100 Mopar Electronic ignition:

318 Foam Dome Air Cleaner.jpg



1989 D100 Mopar HEI conversion and E-Coil.

Air Cleaner HEI.jpg


Here are the HEI conversion parts used:

HEI Setup.jpg


I was quite surprised when working on the '89 Truck of how fast and quick it started, having remembered the slow starts with the '76 D100.

Whatever small amount of fuel vapors that remained in the intake runners and the carb and accelerator pump, the '89 provided instant starts... Like Wow.....

The '76 not so much.

Now guys I ask, where is the "Magic" between these 2 different setups?

Just stumbled across this by wanting a better and simpler working system.



I did some experimenting with an electric fuel pump at the same time, but don't like them.

Electric Fuel Pump.jpg


Just want to run the stock manual fuel pump instead > much simpler.

Here is the '89 D100 with the 4 bbl HEI conversion, starting and working well.

89 D100 318 HEI.jpg


Open to thoughts on the subject.

I was doing carb and ignition testing on a stock built 360 on the engine run stand at the shop. Was very surprised of the quick starts when it was switched over to the Mopar HEI converstion and E-Coil. This is what convinced me to do the HEI conversion to the '89 Truck, glad I did it > better than expected results. No more crank, crank, crank.

Thank You


* * * * *
 
I had another car that had this same problem. I put a fuel pump on it. I could actually hear the pump running with no load until the bowls filled and then the pump had back pressure and the pump tone changed. Once installed and fuel was in the bowls it always fired right away. I thought I would ask here before doing so and appreciate the comments and suggestions..
 
I had another car that had this same problem. I put a fuel pump on it. I could actually hear the pump running with no load until the bowls filled and then the pump had back pressure and the pump tone changed. Once installed and fuel was in the bowls it always fired right away. I thought I would ask here before doing so and appreciate the comments and suggestions..
Perfect. Yes you can hear the pump change pitch when the bowls are full. A momentary switch protected by a fuse on a switched circuit is a good plan.
 
If you don't want to install a pump you can try this .

Or—faster, easier, cleaner, and hella safer—fill the bowl thru the vent like he says, but with a few seconds of spray from a can of carburetor cleaner, rather than open flasks and syringes of gasoline.
 
Just thinking about how an engine shuts down when you want to turn it off. You cut the ignition and it quits firing the fuel that is in there.

Now there still will be some fuel still trapped in the bowels of the engine, intake runners and closed valve cylinders. Just need a good hot spark on startup to light it up again. Then the carb will pick it up again and start adding fuel as required to keep it all going.

Fun to think about.....


* * * * *
 
1976 Dodge D100 with an '89 318 Roller Engine with and Edelbrock 1406 4 bbl and Mopar Electronic Ignition and ballast resistor. Foam Dome Air Cleaner, evaporates the fuel out the top after sitting more than 24 hours, creating crank crank crank hard starts.

Now had a same year '89 318 roller (in a '89 D100) with the 1406 4 bbl converstion and manual fuel pump and the Mopar HEI Distributor and high powered E-Coil, no ballast resistor straight 12 volts to power it. This one has the small chrome top air cleaner for less evaporation. Always instant starts even after sitting for a few days
IMHO

The only way to tell if it is any one particular part would be to swap them from engine to engine ONE at a time to see if you can duplicate the hard start on the other engine.

There are so meny other things then the ignition system at play.
 
If the car is warmed up when it does this. Your fuel is boiling and causing flooding of the engine? You need a return fuel line . The floats cannot operate with boiling ethanol fuel
 
If the car is warmed up when it does this. Your fuel is boiling and causing flooding of the engine? You need a return fuel line . The floats cannot operate with boiling ethanol fuel
It also sometimes has that issue, I wondered why. How would you tap in to the stock carb bowl to do this? Isn't there a vent like Hollys have??
 
OK this should make an interesting conversation on the subject as I have dealt with this problem myself.

1976 Dodge D100 with an '89 318 Roller Engine with and Edelbrock 1406 4 bbl and Mopar Electronic Ignition and ballast resistor. Foam Dome Air Cleaner, evaporates the fuel out the top after sitting more than 24 hours, creating crank crank crank hard starts.

Now had a same year '89 318 roller (in a '89 D100) with the 1406 4 bbl converstion and manual fuel pump and the Mopar HEI Distributor and high powered E-Coil, no ballast resistor straight 12 volts to power it. This one has the small chrome top air cleaner for less evaporation. Always instant starts even after sitting for a few days.

Both engines have the fast turning mini starters of '89 Trucks.

1976 D100 Mopar Electronic ignition:

View attachment 1716354731


1989 D100 Mopar HEI conversion and E-Coil.

View attachment 1716354732

Here are the HEI conversion parts used:

View attachment 1716354734

I was quite surprised when working on the '89 Truck of how fast and quick it started, having remembered the slow starts with the '76 D100.

Whatever small amount of fuel vapors that remained in the intake runners and the carb and accelerator pump, the '89 provided instant starts... Like Wow.....

The '76 not so much.

Now guys I ask, where is the "Magic" between these 2 different setups?

Just stumbled across this by wanting a better and simpler working system.



I did some experimenting with an electric fuel pump at the same time, but don't like them.

View attachment 1716354736

Just want to run the stock manual fuel pump instead > much simpler.

Here is the '89 D100 with the 4 bbl HEI conversion, starting and working well.

View attachment 1716354737

Open to thoughts on the subject.

I was doing carb and ignition testing on a stock built 360 on the engine run stand at the shop. Was very surprised of the quick starts when it was switched over to the Mopar HEI converstion and E-Coil. This is what convinced me to do the HEI conversion to the '89 Truck, glad I did it > better than expected results. No more crank, crank, crank.

Thank You


* * * * *
I have one thought on why the '89 may have responded so well as opposed to the '76, with otherwise similar engines.
The '89, having originally been a TBI engine, already has an in-tank electric fuel pump. Unless you removed/disabled it or swapped in an earlier style tank, it would still be in there functioning...? Please clarify- I'm curious, not trying to be picky.
 
I have one thought on why the '89 may have responded so well as opposed to the '76, with otherwise similar engines.
The '89, having originally been a TBI engine, already has an in-tank electric fuel pump. Unless you removed/disabled it or swapped in an earlier style tank, it would still be in there functioning...? Please clarify- I'm curious, not trying to be picky.

Both engines and trucks were set up exactly the same. Manual fuel pumps on the blocks, with draw tubes out of the tanks, no electric in the tank fuel pumps. Both had the Edelbrock 4 bbls.

The only real difference between the 2 trucks were one had the stock mopar electronic ignition, and the other had the Mopar HEI conversion with the high output (60,000 volt) E-Coil.

Stock Mopar ignition tower coils only put out about 30,000 volts... about 1/2 what the E-Coils produce.

Thanks


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