[Nick 69 302]

I tried to start her up after she sat in my garage for 2 months without turning her over frequently (wasn't in the country to do it). When i did get her going i turned her off after about 2minutes running only to then not be able to restart her. Think i then flooded her and a huge backfire of black smoke came out the carb. I pulled all the plugs and replaced them, let her dry off for a few days and still can't start her. at one point i had her running for about a minute with one plug out. didn't expect that to happen. put all plugs in and tried for two hours to get her started but with no luck. Any ideas why she's not going yet? I don't know alot as i'm learning as i go. All plugs get a good spark and ignition is good too. I'm confused?

Cheers

Nick
1966 289 convertible
1969 302 convertible

[jlp66stang]

If it is still flooding, maybe float is stuck, a little tap may free it up.

[The Greek]

Do you have a Holley carb on the engine? On the older Holleys a backfire up through the carb will rupture the power valve. When this happens it will cause the engine to flood. The newer Holleys have a small check valve installed to prevent this, but it's not fool proof, I've seen them blow out power valves too, if conditions are just right.

It could be the needle and seat on the float sticking, as mentioned before too. If you have an Autolite 2100 (2 barrel) or an Autolite 4100 (4 barrel) the power valve is the same as the Holley's and they can blow out also, with the same results, engine flooding.

[Nick 69 302]

Thanks for that guys, Could need a new carb then. It's a auto 4100 4 valve i'm pretty sure of that. how can i check if it has blown a valve inside before replacing it?
One thing i forgot to mention was that when it does flood during restart attempt, the rear 4 plugs seem soaked in fuel, but the front 4 plugs remain bone dry. Is this a sign that it is carb? why don't all the plugs get wet?

nick

[The Greek]

What you describe as the problem leads me to believe it's the power valve. The power valve has a rubber diaphram. One side is exposed to the fuel in the fuel bowl. The other side is exposed to a vacuum port that picks up its vacuum from a small drilled hole in the base of the carb. When the diaphram ruptures the fuel in the fuel bowl will drain out and into the engine when the engine is not running. It's like pouring a half of a cup of fuel down the carb. It's the total amount of fuel in the primary fuel bowl.

As for why the rear four plugs are wet, it could be because most engines tilt slightly to the rear. Fuel wont flow up hill so from the carb, which is the middle of the engine to the last four cyls. makes sense.

If you get a power valve buy a Holley, not some parts store junk. The off-brand stuff won't flow fuel well. The power valves are rated by the amount of vacuum that is needed to open the valve. Most engines do well with a valve rated at 6.5 inches of vac. They can be bought as a separate piece and they cost about 13 bucks. They are easy to replace, but you will have to pull the carb to remove it. It's located on the bottom front and has a small cover held in place by four screws. Pull the cover and using a one inch socket or wrench unscrew it counterclockwise to remove it. The beauty of the 4100 is that it uses some of the Holley parts which are easy to find.

The 4100 carb is one of the finest designs ever and one that is in great demand.

[astumpf]

heres the problem with carbs...one big backfire can blow out the powervalve in it. i did the exact same thing with mine. only one big backfire and i was screwed.

[MARKMARTIN]

Get an edelbrock 1406. I've seen them at the autoparts store, or you can try Dallas Mustang. It's a 600cfm unit that you can get with or without an electric choke.

I have one on mine and it works great. I had a holley 650 and was experiencing the same flooding and backfire issues.

No powervalve to blow out. No problems.

[The Greek]

People that use Holleys, myself included, have to have a love-hate relationship with the things. I love them because they have a lot of tuneability, I hate them because they're tempermental. If anyone uses a Holley, they had better get an education on them or else they'll never get the darned thing to work right.

The Autolite 4100 is not that way. The only problem that they really have is that the power valve will blow out if you get a backfire up through it. Just like the Holley. Other than that they are one of the most trouble free carbs ever made.

I agree that the Edelbrock carbs are a simpler and less tempermental carb, but I wouldn't take the 4100 off just because the power valve needs replacement. The Edelbrock line of carbs is nothing more than updated Carter AFBs and AVSes. I prefer the AVS for a street engine because of the progressive secondary actuation which is similar in effect to a vacuum secondary Holley. The AFB has a mechanical secondary activation which is a non-progressive setup, it's either open or it's closed. Progressive secondaries only open to the amount that is needed by the engine in relation to the demand placed on it.

[OogeyBoogie]

Hey Nick...sounds like ya got some good answers from these nice people. I can speak from personal experience that they are right on the money when mentioning a sticking float in the carb tanks and/or blown power valve. Good luck to you in fixing it...and should you decide to work on it yourself..remember..take your time...avoid getting frustrated...and...make sure you are aware of where ya remove things from

[Nick 69 302]

Cheers all for the great advice. I'd certainly have been screwed without all this info. Cheers again GLP66STANG, THE GREEK, ASTUMPF, MARK MARTIN and OOGEY BOOGIE! All the best

[2LUCKY25]

Hi Hun How R U And The Girl Is She Running ?