[xk49]

1964 327 with Holley 670 Street Avenger carb, electronic choke. Car starts great when cold(one tap of the gas pedal, turn key, and like in 1-2secs fires right up). Car starts great hot(don't touch the gas pedal, turn key, 2-3secs fires right up). My problem is when I drive the car and let it sit for like 1/2 to 1 hour, it won't start. I don't touch the gas pedal because I think everything is still primed and warm. I'll try for three or more times, but nothing. That's when I say, "hey, maybe it's in a cold state and I need to engage the choke", so I give the gas pedal a pump, but that will usually do nothing too. Now I think it's flooded as if I wait like another 1/2 hour for the engine to really cool down, it will fire up, but only after like 4-5secs of starter engagement.

Any ideas where to start at diagnosing the issue?

 

[drivejunk]

Have you tried holding the throttle partly open when cranking, during warm restarts?

Even EFI can take additional cranking in that scenario and most OEM owner's manuals from the carb era say hold the gas pedal down halfway.

Its not necessarily an issue, unless it goes beyond that in my opinion. Don't stroke the pedal, just crack it open.

 

[z27]

Have you tried holding the throttle partly open when cranking, during warm restarts?

Even EFI can take additional cranking in that scenario and most OEM owner's manuals from the carb era say hold the gas pedal down halfway.

Its not necessarily an issue, unless it goes beyond that in my opinion. Don't stroke the pedal, just crack it open.

sounds like an old G/M malady heat soak. If your problem is it won't crank or cranks slow the first thing to check is your distributor in right and in phase. this needs checking because it will run up to two teeth of eighter way but not really good or well. That said if the carb and timing are good now you need to check the starter battery and cables for draw and capacity. My guess, it's going to be a heavy draw. The solution to this is one get the biggest high CCA battery you can fit in the box. Two get 6-volt heavy duty battery cables to carry the amperage to the starter and lastly get a high torque starter for the application . If the problem is hot heat soak which was very common way back your problem will be cured . OPne more thing you may as well check the charging system while your at it also. that should cover it hope this helps . Alex

 

[123pugsy]

sounds like an old G/M malady heat soak. If your problem is it won't crank or cranks slow the first thing to check is your distributor in right and in phase. this needs checking because it will run up to two teeth of eighter way but not really good or well. That said if the carb and timing are good now you need to check the starter battery and cables for draw and capacity. My guess, it's going to be a heavy draw. The solution to this is one get the biggest high CCA battery you can fit in the box. Two get 6-volt heavy duty battery cables to carry the amperage to the starter and lastly get a high torque starter for the application . If the problem is hot heat soak which was very common way back your problem will be cured . OPne more thing you may as well check the charging system while your at it also. that should cover it hope this helps . Alex

Seems to me it's turning over fine, just not starting/flooded.

 

[xk49]

Seems to me it's turning over fine, just not starting/flooded.

Correct, super strong turnover on the engine. New battery begining of the summer and I believe the starter is a high powered mini starter. I think I'll try the partial pedal press next time. I assume by doing a lite press of the pedal it won't do the spray/choke like a blip of the pedal.

 

[123pugsy]

Hold the gas pedal to the floor if you think it's flooded. No pumping.

 

[Jasons 69 Chevelle]

Vapor lock

 

[drivejunk]

Correct, super strong turnover on the engine. New battery begining of the summer and I believe the starter is a high powered mini starter. I think I'll try the partial pedal press next time. I assume by doing a lite press of the pedal it won't do the spray/choke like a blip of the pedal.

You don't want to stab the pedal or stroke very far or you'll add accelerator pump shot to the problem. Just crack the throttle enough so it won't tug on the idle circuit when cranked. It just has to suck the partially condensed gas/fog sitting in the intake through. Crank til it fires then lift off the pedal. You'll get a feel for how long to crank to clear all eight and fire right up gracefully.

If its that.

Choke should not set if engine is warm.