No start question

[Jamz33]

I have a 78 cobalt with a 350. You can run it for maybe 30 minutes, or sometimes maybe 5 minutes, and once you shut it off it won’t start until it cools down. And if it starts it won’t plane out. Idles fine. I have ruled out fuel by using a jug once it starts acting up to bypass the tank and before that tried pouring fuel into carb thinking maybe it was running out of fuel. Points and condenser have been changed. Carb has been gone through. Could this be a timing issue? Any suggestions please.

 

[Scott Danforth]

What did you set dwell to?

What is your timing set to?

How hot does the motor get? Have you serviced the raw water pump?

 

[Jamz33]

What did you set dwell to?

What is your timing set to?

How hot does the motor get? Have you serviced the raw water pump?

I don’t believe it’s getting hot. And we haven’t checked the timing yet. I was just wondering if a timing issue could cause this or would timing cause it to more run rough/not run from the start? Also what do you mean by “dwell”?

 

[dubs283]

Dwell is the amount of time measured in degrees of rotation of the distributor shaft the points are open

Need to set dwell first, roughly 28-30 degrees for a sbc. Then set timing, ought to be 8 degrees btdc for your engine

Yes, dwell/timing is important for proper starting and runnability for the engine

Have you changed the cap/rotor, plugs, wires, fuel filter(s)?

Is the battery and connections sound?

What does carb gone through mean? Rebuilt or simply inspected/adjusted?

 

[Scott06]

I don’t believe it’s getting hot. And we haven’t checked the timing yet. I was just wondering if a timing issue could cause this or would timing cause it to more run rough/not run from the start? Also what do you mean by “dwell”?

dwell is want you set the points to - it is the amount of time that the points are building up energy in the coil. If you changed the points and didn't set dwell I would start there. Yes if timing is off it may not run, set timing as well.

this is a great video on how to tune up points ignitions. Note the blue color of the spark in video that's what a good hot spark looks like

If you had spark and dumped gas in carb it should cough or run.

 

[Jamz33]

dwell is want you set the points to - it is the amount of time that the points are building up energy in the coil. If you changed the points and didn't set dwell I would start there. Yes if timing is off it may not run, set timing as well.

this is a great video on how to tune up points ignitions. Note the blue color of the spark in video that's what a good hot spark looks like

If you had spark and dumped gas in carb it should cough or run.

Ok thanks for the help.