67 BB - Issues starting when warm
Thread Starter
Instructor
Joined: Mar 2006
Posts: 110
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67 BB - Issues starting when warm
I am hoping you all can help my Dad and I out with a starting issue we are experiencing.
My Dad and I are thinking that we have a vapor lock issue where when the car sits for a while while the engine is warm fuel leaks into the carb and floods the motor.
Here is where the fun comes in. We have not been able attempt to fix the issue because we do not have clearance to install phenbolic spacer with the current intake and carb setup. Keep in mind this is with the BB stinger hood. I know the current intake is an edelbrock, but I will have to check and see what model.
So, my question is, does this sound like a vapor lock issue and if you think it does can you suggest an intake that will allow us clearence to install a phenbolic spacer.
Thanks in advance!
Blake
- Starts fine when the engine is cold. A few pumps on the gas and she fires right up.
- Starts fine when the engine is warm and the car has been off for less than 10-15min.
- We have issues starting if the car is warm and sits longer than 15min. To get it started we have to hold it WOT until it starts.
My Dad and I are thinking that we have a vapor lock issue where when the car sits for a while while the engine is warm fuel leaks into the carb and floods the motor.
Here is where the fun comes in. We have not been able attempt to fix the issue because we do not have clearance to install phenbolic spacer with the current intake and carb setup. Keep in mind this is with the BB stinger hood. I know the current intake is an edelbrock, but I will have to check and see what model.
So, my question is, does this sound like a vapor lock issue and if you think it does can you suggest an intake that will allow us clearence to install a phenbolic spacer.
Thanks in advance!
Blake
Drifting
Joined: Feb 2011
Posts: 1,259
Likes: 18
From: Dixon California
This is my story starting BB after hot....finally a mech asked where battery ground was attached? said move the ground from frame rail to as close to the starter as you can( I attached to (ground ) to bellhousing ..thus elimating the ground to travel through the Rubber mtr mounts.....In your case a simple ground change could be a path to starting hot.....worked for me....I on previous BB I installed a electric fan at rad blowing out ...when I shut car off the fan was set to blow for aprox 15 min..and then shut off.....seemed to cool the engine compartment and not perhaps (boil) the gas At carb also pop the hood to help disipate heat...
Bluzrocker
Bluzrocker
Thread Starter
Instructor
Joined: Mar 2006
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This is my story starting BB after hot....finally a mech asked where battery ground was attached? said move the ground from frame rail to as close to the starter as you can( I attached to (ground ) to bellhousing ..thus elimating the ground to travel through the Rubber mtr mounts.....In your case a simple ground change could be a path to starting hot.....worked for me....I on previous BB I installed a electric fan at rad blowing out ...when I shut car off the fan was set to blow for aprox 15 min..and then shut off.....seemed to cool the engine compartment and not perhaps (boil) the gas At carb also pop the hood to help disipate heat...
Bluzrocker
Bluzrocker
Racer
Joined: Feb 2011
Posts: 497
Likes: 7
From: Sweden
How do you try to restart when hot? Do you touch the gas pedal or just put the key in and turn? You shouldn't have to touch the pedal. Does the car stall when hot or just not refire?
The next time you get the motor nice and hot and shut her off, try to restart her by pushing the pedal to the floor and holding it there. DO NOT PUMP THE PEDAL!!! If she starts this way, then you are having a percolation issue.
And of course , what is your initial timing.. If your initial is high (18 degrees or so) than try backing it down a little. Advanced timing in engines are hard starting when they are hot.
And if your needle and seats are week when you shut the motor off the heat from the engine will boil the gas in the carb and it will bypass the seat and flood the motor with gas. just a thought, had it happen to a buddy of mine.
The next time you get the motor nice and hot and shut her off, try to restart her by pushing the pedal to the floor and holding it there. DO NOT PUMP THE PEDAL!!! If she starts this way, then you are having a percolation issue.
And of course , what is your initial timing.. If your initial is high (18 degrees or so) than try backing it down a little. Advanced timing in engines are hard starting when they are hot.
And if your needle and seats are week when you shut the motor off the heat from the engine will boil the gas in the carb and it will bypass the seat and flood the motor with gas. just a thought, had it happen to a buddy of mine.
Team Owner
Joined: Aug 2007
Posts: 58,061
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Army
If its percolation, oftentimes you can hear the fuel boiling in the carbs. Buy a Harbor Freight I/R temp gun for a few bucks and shoot the fuel bowls when your problem occurs. If they are spiking much over 150* then perc may well be the problem.
Le Mans Master
Joined: Nov 2008
Posts: 5,691
Likes: 12
From: columbus oh
sounds exactly like a fuel perc. problem....there is no remedy as a spacer will not fit under the hood...some of this can go away if you block off the heat riser gaskets on the intake ....
double check your timing to see if you have enough initialand run full time vacuum to the vac. advance if you are running one
sea foam additive in the tank does help somewhat, other than that you will have to live with it...be sure the floats are set correctly.....good luck...jmo...
double check your timing to see if you have enough initialand run full time vacuum to the vac. advance if you are running one
sea foam additive in the tank does help somewhat, other than that you will have to live with it...be sure the floats are set correctly.....good luck...jmo...
Melting Slicks
Joined: Jul 2004
Posts: 2,867
Likes: 195
From: Maryland
One possible cure is to use racing gas which has no ethanol and a higher boiling point.
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Le Mans Master
Joined: Jan 2000
Posts: 8,918
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From: New Hill NC
This is a common condition with any Holley, especially the ones with a rear metering plate. The plate warps. Gas gets into the vent circuit and floods the rear barrels. A new metering plate or straightening the old one with some gasket sealing will solve the problem. In the mean time start the engine by using the flood clearing method of holding the throttle down until it starts. Don't pump the throttle, just hold it down until it starts.
Thread Starter
Instructor
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Pro
Joined: Jul 2008
Posts: 622
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From: Clermont Florida
The problem is the alcohol in today's fuel, that causes it to boil off and flood the engine if it sits for a while when hot. I had the same problem. Check your area for a gas station that sells fuel with no alcohol in it. There are at least 2 here in little Durango, so you should be able to find one. This should help a great deal.
Melting Slicks
Joined: Apr 2003
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From: Florida
Le Mans Master
Joined: Jan 2000
Posts: 8,918
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From: New Hill NC
The problem is that the metering block is pot metal and it sits on a stack of gaskets one of which is thick. The torque of the screws eventually warps the block. The seal of the gasket is lost and it opens the path for the fuel to travel into the passage and eventually into the engine. It is very common and happens to almost all of them. I have straightened the blocks, but it is chancy. The best way is to get a new one. I use some epoxy on the lower part of the block to seal the gasket. You have to be careful and not use much. You don't want any squeeze out into the passages. With a new block you don't want to over tighten the screws. It contributes to the problem by stressing the block. Do that and your hot start problem will go away.