Car stalling at idle and some other weird stuff

I have a friend who has a 502 Chevy in his 68 Tempest and when he came over today he had a really hard time getting his car back home and we have no idea what the problem is. I think it's a carb problem, due to some things that we tried to correct it.

Now mind you, I have no experience with carbs other than the basic tune up procedures, so I hope that I can give enough information to you guys to see if anyone will be able to help us.

I know that it's a Holley double pumper carb, I think it's an 800 or 850, electric choke and is about 2 years old.


The problem is that when the car pulls up to a stop light, the engine just dies and will not start again until the hood is opened. o No: Once the hood is opened, the car starts right up. o No: I thought it was just some coincidence when he told me that, so we tried it several times and sure enough that's exactly what happens. The car cranks and it smells of raw gas, but won't fire, until the hood is opened.

He normally runs with a K&N air filter, the type that uses the entire air cleaner, the top and sides. When he uses that air cleaner (which was just cleaned a week or so ago), the car will start with the hood all the way opened, but as soon as it is closed about half way, the motor dies. He switched to a regular paper air cleaner and the hood only has to opened a couple of inches and it will start right up, and will idle fine, until it has been driven and then stops, then the motor dies.

He has a GTO hood on the car with the holes in scoops drilled out to allow more air in, and once the car gets moving, it's okay and runs fine.

The carb has black soot all over the plates on top and in the bottom of the chrome top that is used for the paper air cleaner. The secondary system plates are also covered in black soot.

I thought that maybe he had an electrical problem and maybe a pinched wire in the hood hinges, but there is nothing near the hinges or the latch mechanism. Once, the motor sputtered to a stop and the engine spewed smoke up through the carb and out the ram air scoops (looked like a dragon), which made me think maybe it was something to do with the timing.

A neighbor mentioned that it could possibly be the accelerator pump. Does that sound possible?

So, since I have no idea about working on Holleys (I didn't even see an air/fuel mixture screw), I thought maybe some of the strange things that happened might strike a chord with some of you guys and you might be able to enlighten us as to what it possibly could be. It's such a strange thing that it has something to do with the hood (or at least that's what it seems like). I think the car is possessed and wants me back as it owner again. :grin:

 

It's possible that the carb could be to close to the hood, causing a choking effect, kinda like putting your hand over the carb.