13james13 wrote:

Okay Mustang Steve here's one for you ☺ and I'm not the only one with this isue. 289 four barrel points or electronic ignition. Early morning crank up, cranks and runs just fine. but say I go into Walmart come out, motor is warm, it takes several, several cranks before it will start. Or if I turn it off and right back on it cranks and runs fine. It's that 30 minutes or so while the motor is still warm it won't bust right off. Any suggestions? Thanks. ☺

Sounds like the same problem I have.   Its a combo of vapor lock and heat soak.   
 

I have never had this problem on a carb that is sealed up with good gaskets and diaphragms, but have had it once when the accelerator pump diaphragm went bad.

Check your accelerator pump diaphragm.  It is probably leaking just enough to lower the fuel level in the bowl.  It evaporates on the hot engine so you don't see it get wet, but the fuel is going out of the bowl somehow.

I suppose you could have some kind of vapor lock where an air bubble gets trapped in the line, but if everything is set up correctly, this should never happen.

No, if you are able to drive the car, it obviously will still squirt gas.  Usually it gets a crack in the diaphragm and gas is able to seep through the crack even though it still functions.

After you park the car, run your finger under the diaphragm housing after a few minutes and see if it is wet.  HEck, don't waste your time.  If it is hard to start after sitting, just replace the diaphragm and it will probably cure it unless you have some weird fuel lines that are touching the engine or something weird.

I do not know details on this, but I have heard of a fuel pump with a bad check valve siphoning gas from the carb when parked.  Maybe someone knows more about that than I do.

But the bottom line is the carb is losing its supply of gas and you have to crank the engine to reprime it.

Well Tubo, since you brought it up, how many times have you had a fail to start or continue to run with your EFI?

thanks Mustang Steve!

Our car did that when we first got it running, timing was too advanced. Corrected timing, problem solved.

Bob

13james13 wrote:

hey bullet Bob. Could you give me some help on those acronyms please?

Sorry James. 
EFI = Electronic Fuel Injection
PCM = Powertrain Control Module (the computer)
AFR = Air Fuel Ratio (rich or lean, it's fairly well fixed with a carb but is constantly adjusted with EFI)

BB

 

Good thought M1R, also when cold the choke is closed. Hmmmm?

Sounds like boiling fuel which accumulates in the intake, causing a too rich condition. I have had that happen on old Fords. Try pushing the gas pedal all the way down and hold it there, then crank the engine with the carb blades wide open to get some air in there. No pumping of the gas pedal, that makes it worse.

MustangSteve wrote:

Mach1_Ron wrote:

13james13 wrote:

It's that 30 minutes or so while the motor is still warm it won't bust right off. Any suggestions? Thanks. ☺

So if he looses gas from the bowls, then how does it sitting overnight NOT require him to reprime the pump???
 

OK, looks like I missed that about starting fine in the morning.  Thanks, Ron.  Back to that heat soak, vapor lock thing.  Answer still holds true about good gaskets and having proper routing of the fuel line away from heat sources.

Next time it occurs, quit trying to start it.  Remove air cleaner.  Note the choke position. Move throttle linkage manually and check for squirter operation to see if it has fuel to squirt.  Then we can go from there.
 

Alright I'll try that. Thank you! I'm running headers, so heat source to choke is capped. Carburetor has no heat other than manifold warming up. I'm running a 180 thermostat, north Florida.  The butterfly is "open cold" about 3/8 inch and fully opens when warmed up. My metal fuel filter is about 2 inches from the header and EFI fuel line is about 3/4 inch away from the front end of valve cover, goes up from there to base of carb. I can easily raise the fuel line and filter up another inch. Just so everyone is aware I'm running basically the same setup as I did in 1980's, except .030 bore. I don't recall this issue back then. I appreciate all your help.☺ Thanks again!

MarkinSC wrote:

13james13 wrote:

Okay Mustang Steve here's one for you ☺ and I'm not the only one with this issue. 289 four barrel points or electronic ignition; Early morning crank up, cranks and runs just fine. but say I go into Walmart come out, motor is warm, it takes several, several cranks before it will start. Or if I turn it off and right back on it cranks and runs fine. It's that 30 minutes or so while the motor is still warm it won't bust right off. Any suggestions? Thanks. ☺

Is this a stock 4 bbl intake or an aftermarket intake?
Do you have a spacer between the carb and the intake? If so, do you have a gasket between the spacer and the carb, and between the spacer and the intake?
What type of carb?  stock or aftermarket?
What kind of choke?
 

Its a old school, Torquer 289 Elderbrock Highrise. No spacer, gaskets are good, very small leak at throttle body rod. 650, 4 bbl Autolite carburetor with mechanical choke. Thanks for your input!

13james13 wrote:

MarkinSC wrote:

13james13 wrote:

Okay Mustang Steve here's one for you ☺ and I'm not the only one with this issue. 289 four barrel points or electronic ignition; Early morning crank up, cranks and runs just fine. but say I go into Walmart come out, motor is warm, it takes several, several cranks before it will start. Or if I turn it off and right back on it cranks and runs fine. It's that 30 minutes or so while the motor is still warm it won't bust right off. Any suggestions? Thanks. ☺

Is this a stock 4 bbl intake or an aftermarket intake?
Do you have a spacer between the carb and the intake? If so, do you have a gasket between the spacer and the carb, and between the spacer and the intake?
What type of carb?  stock or aftermarket?
What kind of choke?
 

Its a old school, Torquer 289 Elderbrock Highrise. No spacer, gaskets are good, very small leak at throttle body rod. 650, 4 bbl Autolite carburetor with mechanical choke. Thanks for your input!

shall I assume that you had the same issue with both points and with electronic ignition?
I'm confused about the EFI fue lines you have with a carb setup?