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412 Posts
Discussion Starter #1
Car: 66 I-6 200CID, Manual trans. Carb was rebuilt about 1 year ago.

Car is not currently on the road. Finally recovering from a case of "While I'm at it!" (That was a PAIN!!!).

Engine starts easily, idles fairly smoothly around 725-775 RPM.

If I give it gas slowly (say, 1-2sec to WOT), it revs right up. No problem. Does not stall when letting off.

However if I have it idling and I stomp on the gas, she sputters for 1/2 sec, then dies. Restarts quickly and easily. If I let off before she dies, while she's sputtering, the engine will recover it's origonal RPM.

Any ideas on where to start looking? Vacuum leak? Fuel pressure? Carb need a rebuild (again)?



3,595 Posts
Sounds like a case of:

1. Accelerator pump not working properly. Easy to check by removing the air cleaner and looking down the carb throat while manually operating the accelerator linkage (engine OFF) and observe if there is a healthy squirt of gas.

2. Vacuum advance diaphragm ruptured and not giving any spark advance. Check by removing the distributor cap and disconnecting the line to the carb. Suck on the line and see if the breaker plate in the distributor moves. Hold suction on it and see if it bleeds off.

3. Not enough intial advance on your timing.

One of the three, or a combination of 2 & 3.

Have fun!
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