Inliners International Forums General Discussion Engines Choke has no effect

Gentlemen,

My 250 Chevy has a Offy 5416 intake manifold with an Edelbrock #1403 , 4 bbl, 500 cfm carb. When I close the choke when the engine is warmed up and idling, there is no change in the way the engine runs. Shouldn't there be some effect? Also, my Air Fuel gauge shows no change. Thank you.

Ken

There should be. Sounds like either the coIL isn't getting juice or the linkage is gummed up.

gbauer,

Thanks for getting back to me.

The choke mechanism functions. The coil is getting voltage and moving the arm, which of course moves the choke blade. But when the choke blade is closed, the A/F mixture gauge does not register richer, nor does the engine RPM change. Shouldn't one or both of those changes happen?

Ken

The engine RPM is a matter of the fast idle screw. The A/F mix should change. On a Holley it's a matter of loosening the 3 screws that hold the choke in and turning it. Not sure on an Edelbrock but it's probably similar.

If you manually close the choke plate, the engine should be affected.
Possibly there is a vacuum leak that overrides the choke.

Will Willis

Put your hands over the throat of the carb and try to seal it off while running. If it doesn't die you have a vacuum leak.

You have a leak for sure somewhere. The idle should rise when the choke is closed for warm up and when the engine is warm the choke will open to let it idle. If the choke is closed when the engine is hot the engine should die. I can say...more than likely you have a vacuum leak. Check for vacuum leaks with some carb cleaner by spraying around the base of the carb and on the manifolds....any rise or fall in rpm and that's where your leak is. Edelbrocks have a large port hole for P/B setups....did you put the screw in plug in? Your probably running PCV...plug that off to and see if that helps anything.

The easiest way to test the accessories connected to the carb and intake is to pinch hoses. 3 vac connections on the carb: one to PCV, one to vac advance, and one to auto trans. If you don't have three hoses connected find the bungs and close the one not connected.

I doubt a gasket leak is going to be this excessive.

On mine I had a similar problem. Eventually I figured out the trans line wasn't connected at the trans. Up top everything looked perfect. The trans line went from the carb, through a short rubber hose, to a hard line, down to the output shaft, through another rubber hose and into the transmission (powerglide). It was that final rubber hose that had issues.

Once I fixed that everything came together quickly. It only took me 6 months to find the problem. Only.